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J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195

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Journal of Behavior Therapy andExperimental Psychiatry

journal homepage: www.elsevier .com/locate/ jbtep

Internet-based Cognitive Bias Modification of Interpretationsin patients with anxiety disorders: A randomised controlled trial

Elske Salemink a,*, Merel Kindt b, Henk Rienties c, Marcel van den Hout a

aDepartment of Clinical and Health Psychology, Utrecht University, Utrecht, The NetherlandsbDepartment of Clinical Psychology, University of Amsterdam, Amsterdam, The NetherlandscAltrecht Academic Anxiety Centre, Altrecht, Utrecht, The Netherlands

a r t i c l e i n f o

Article history:Received 28 March 2013Received in revised form2 October 2013Accepted 3 October 2013

Keywords:Anxiety disordersCognitive Bias Modification ofInterpretationsInternet-based

* Corresponding author. Present address: Departmchology, University of Amsterdam, Weesperplein 4Netherlands. Tel.: þ31 205258663; fax: þ31 2063902

E-mail address: E.Salemink@uva.nl (E. Salemink).

0005-7916/$ e see front matter � 2013 Elsevier Ltd.http://dx.doi.org/10.1016/j.jbtep.2013.10.005

a b s t r a c t

Background and objectives: Previous research suggests that negative interpretation biases stimulateanxiety. As patients with an anxiety disorder tend to interpret ambiguous information negatively, it washypothesised that training more positive interpretations reduces negative interpretation biases andemotional problems.Methods: In a randomised, double-blind placebo-controlled trial, patients with different anxiety disor-ders were trained online over eight days to either generate positive interpretations of ambiguous socialscenarios (n ¼ 18) or to generate 50% positive and 50% negative interpretations in the placebo controlcondition (n ¼ 18) (Study 1).Results: Positively trained patients made more positive interpretations and less negative ones thancontrol patients. This training was followed by a decrease in anxiety, depression, and general psycho-logical distress, but this effect was also observed in the control group. To get a better understanding ofthese unexpected results, we tested a 100% neutral placebo control group (Study 2, n ¼ 19); now thescenarios described neutral, non-emotional situations and no valenced interpretations were generated.The results from this neutral group were comparable to the effects from the other control group.Limitations: An advantage, but potentially also a disadvantage of the study is that CBM-I training wasperformed online with less control over the procedures and setting. In addition, the scenarios were notmatched to the specific concerns of each patient and the training sessions were performed in closeproximity to one another.Conclusions: Compared to both control conditions, CBM-I had superior effects on interpretations, but noton emotions. The current findings showed the boundary conditions for CBM-I.

� 2013 Elsevier Ltd. All rights reserved.

1. Introduction

Cognitive theories argue that patients with an anxiety disorderinterpret potential threatening information as much more threat-ening than they are and this biased interpretation is held to be thepathogenic nucleus of the disorder (Beck, Emery, & Greenberg,1985; Williams, Watts, Macleod, & Mathews, 1988). It is hypoth-esised that biased interpretations are causally related to anxiousfeelings and behaviour and experimental evidence supports thiscausal claim (Mathews & Mackintosh, 2000). Interpretation biaswas modified using a scenario-based Cognitive Bias Modification

ent of Developmental Psy-, 1018 XA Amsterdam, The79.

All rights reserved.

for Interpretations (CBM-I) training and anxiety was affected sub-sequently. In the meantime these findings have been replicatedseveral times (see for an overview Hallion & Ruscio, 2011).

There is overwhelming evidence that patients with an anxietydisorder have the tendency to interpret ambiguity in a threat-related way. That is, patients with a social anxiety disorder (SAD)interpreted ambiguous social scenarios as more negative than anon-anxious control group (Amir, Foa, & Coles, 1998), patients witha panic disorder (PD) were more likely to interpret bodily sensa-tions as signs of threat than other anxiety disorder patients (Clarket al., 1997), and patients with Generalised Anxiety Disorder(GAD) interpreted ambiguous scenarios as more threatening thannon-anxious controls (Butler & Mathews, 1983). In a prospectivestudy, it was shown that interpretation of initial posttraumasymptoms predicted Posttraumatic Stress Disorder (PTSD) symp-toms at six and nine months follow-up (Dunmore, Clark, & Ehlers,2001).

E. Salemink et al. / J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195 187

According to cognitive theories of psychopathology, it isimportant that treatments for anxiety disorders address thesemaladaptive processes. Cognitive Behavioural Therapy (CBT), forexample, aims to alter those biased interpretations via cognitiverestructuring and behavioural experiments. As biases in informa-tion processing are fast and more automatic processes, the use ofverbal dialogue and explicit instructions might not be the optimalapproach to change them (Beard, 2011). Furthermore, processingbiases filter incoming information and may act as a barrier in CBTby hampering the activation of incongruent information (Baert,Koster, & De Raedt, 2011). A recent new development to changethese processing biases in a different way is Cognitive Bias Modi-fication (CBM). It is a computerised training consisting of “extensivepractice on a cognitive task designed to encourage and facilitate thedesired cognitive change” (p. 3, Koster, Fox, & MacLeod, 2009). InCognitive Bias Modification of Interpretation (CBM-I), participantsrepeatedly practice more positive interpretations. Compared toCBT, CBM changes processing biases through practicing the desiredprocess, and not through verbal instruction and explicitly chal-lenging thoughts. Due to the different approach, CBM might haveadded value in the treatment of anxiety disorders.

There is accumulating evidence that CBM-I training has effectsin non-anxious and highly anxious analogue samples. For example,four sessions of positive CBM-I training using scenarios provided tohighly anxious individuals resulted in stronger reductions in traitanxiety scores (d ¼ 0.58) compared to a testeretest control group(d ¼ 0.08) (Mathews, Ridgeway, Cook, & Yiend, 2007). These effectswere replicated in a study where (scenario-based) CBM-I sessionswere increased from four to eight in a sample of highly anxiousstudents with stronger reductions in trait anxiety and levels ofpsychological distress in the CBM-I training condition (d¼ 0.29 and0.41 respectively) compared to a placebo control condition (sce-narios had 50% positive and 50% negative outcomes, d ¼ 0.06 andd ¼ �0.04 respectively) (Salemink, van den Hout, & Kindt, 2009).Similar findings have been observed with different types of CBM-Iparadigms (Amir, Bomyea, & Beard, 2010; Beard & Amir, 2008) andwith different types of highly anxious analogues populations(Hirsch, Hayes, & Mathews, 2009; Steinman & Teachman, 2010;Teachman & Addison, 2008).

To the best of our knowledge, two studies actually examined theeffects of CBM-I in a clinically anxious sample (Amir & Taylor, 2012;Hayes, Hirsch, Krebs, & Mathews, 2010) and two other studiestested a combined training of both attention and interpretation biastraining (Beard, Weisberg, & Amir, 2011; Brosan, Hoppitt, Shelfer,Sillence, & Mackintosh, 2011). Hayes et al. (2010) investigated theeffects of a single CBM-I session in GAD. Forty patients wererandomly allocated to a positive interpretation bias training (ho-mograph and scenario-based training) or a placebo control condi-tion (both training paradigms contained 50% threateninginterpretations). CBM-I successfully modified interpretations andindividuals who had followed the positive training had fewer self-reported negative intrusive thoughts. However, there were nosignificant differences between the groups in change in self-reported anxiety following a worry period (dpositive CBM ¼ 0.03 vs.deterioration in the placebo group dplacebo ¼ �0.19). The lack ofeffects on anxiety might be, among other reasons, due to the factthat individuals were only trained once, whereas multiple sessionsof training might be necessary to obtain emotional effects in aclinical sample. Amir and Taylor (2012) provided a 12 sessioninterpretation training (based on WordeSentence AssociationParadigm, WSAP) to individuals with a generalised SAD. Trainingaffected interpretations and, compared to a placebo control con-dition (receiving 50% positive and 50% negative feedback afterendorsing threatening interpretations), participants who receivedthe training were judged as less socially anxious by clinicians who

were blind to treatment condition (d¼ 1.95 vs. 0.61). However, bothconditions did not differ on change in self-reported social anxietysymptoms; both the training condition (d ¼ 1.23) and the controlcondition (d ¼ 1.29) displayed large reductions in self-reportedsocial anxiety. These first findings in clinical samples seem tosuggest that CBM-I is successful in modifying interpretations, butthat it does not outperform the control condition with respect toself-reported anxiety. Regarding the two studies that examinedCBM-I in combination with attention training in a clinical sample;Brosan et al.’s study (2011) did not include a control group, thus it isunclear whether the observed reduction in self-reported anxiety(dstate anxiety ¼ 0.81, dtrait anxiety ¼ 1.12) is the result of the inter-vention. Beard et al., 2011 compared the combined CBM training(eight sessionsWSAP training) with a placebo condition (attention:probe replaced neutral and disgust faces with equal frequency;interpretation: words were not related to social, but to superficialaspects). A stronger reduction in self-reported anxiety wasobserved in the CBM condition (d ¼ 1.04) compared to the placebocondition (d ¼ 0.20). Even though this result is promising, it is hardto evaluate the role of interpretive bias training, as the effects couldalso be due to the attentional bias training. Up to now, the effects ofCBM-I on self-reported anxiety in clinical populations seem moremixed than the effects in non-anxious and highly anxious analoguesamples. Furthermore, little is known regarding the longevity of theeffects as only Amir and Taylor (2012) included follow-up mea-sures, though only in the CBM-I condition.

CBM-I training is a computerised training that has the possi-bility to be offered to participants via internet. Up to now, however,all published CBM-I studies with clinical samples have deliveredthe training in a laboratory or office setting with participantscoming to that location to complete each training session (Amir &Taylor, 2012; Beard et al., 2011; Brosan et al., 2011; Hayes et al.,2010, but see Salemink et al., 2009 for an online CBM-I training ina highly anxious, but not clinical sample). This is surprising asrepeatedly coming to a certain location might be a barrier for care.People living in remote areas, physically disabled patients withrestrictedmobility, or patients who are hesitant to seek face-to-facetreatment might be better reached with internet-delivered thera-pies (Lange, van der Ven, Schrieken, & Emmelkamp, 2001). Thusinternet-based treatment has the potential to increase availability,but also to facilitate dissemination. In addition, given the contextsensitivity of training effects, online interventions are promising asthey can be completed at home (Macleod, Koster, & Fox, 2009).Furthermore, E-mental health is a promising new area for treat-ment and studies have shown that internet-delivered CBT may beas effective as face-to-face CBT (e.g., Hedman et al., 2011). Finally,web-based interventions have the potential of being more cost-effective. Computerised CBM training paradigms seem ideal in-terventions to be provided online and this has been tested forattentional bias training (CBM-A). The first findings are howevermixed; while it has been shown that attentional bias can bemodified using an internet-delivered training (Macleod, Soong,Rutherford, & Campbell, 2007), another study revealed no supe-rior effects of CBM-A on self-reported anxiety symptoms (Carlbringet al., 2012). The findings of online interpretive bias training in ahighly anxious, non-clinical sample were promising (Saleminket al., 2009).

The aim of the present studywas to examine the effectiveness ofan internet-delivered CBM-I training in a clinical sample of patientswith a broad range of anxiety disorders. In a randomised, double-blind placebo-controlled trial, patients with anxiety disorderswere trained online to either generate positive interpretations ofambiguous social scenarios or to generate 50% positive and 50%negative interpretations in the placebo control condition. Thisplacebo-control condition was developed to control for the effects

Assessed for eligibility (n = 148)

Randomized (n = 47)

Excluded (n = 101)• Met exclusion criteria (n = 42)

Receiving psychological treatment, n = 21No pc / internet access, n = 14Insufficient Dutch literacy, n = 7

• Declined to participate (n = 59)

Allocated to positive CBM-I condition (n = 24) • Received intervention (n = 24)• Did not receive intervention (n = 0)

Allocated to control condition (n = 23)• Received intervention (n = 22)• Did not receive intervention (n = 1)

Refused after randomisation, n = 1

Lost during intervention (n = 4)

Completed intervention (n = 20)• Succesful (n = 18)• Unsuccessful; too many days no training (n

= 2)

Lost during intervention (n = 3)

Completed intervention (n = 19)• Succesful (n = 18)• Unsuccessful; too many days no training (n

= 1)

3 month follow-up assessment (n = 18)• Completed follow-up (n = 14)• Lost to follow-up (n = 4)

Not interested anymore, n = 3Untraceable, n = 1

3 month follow-up assessment (n = 18)• Completed follow-up (n = 16)• Lost to follow-up (n = 2)

Untraceable, n = 2

Analysed• Direct training effects (n = 18)• 3 month follow-up (n = 14)

Analysed• Direct training effects (n = 18)• 3 month follow-up (n = 16)

Fig. 1. CONSORT flow diagram illustrating the flow of participants through the study.

E. Salemink et al. / J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195188

of repeated exposure to emotional social material and non-specifictreatment effects (cf. Hayes et al., 2010; Salemink et al., 2009).Furthermore, to examine the longevity of the effects, a three-monthfollow-up assessment was included for both the CBM-I traininggroup as well as the placebo-control condition. During the eightday program, patients did not receive other treatments as theywere on a waiting list to receive treatment. However, at follow-upassessment three months later, they received treatment as usual. Itwas predicted that positive CBM-I would modify the interpretationbias. That is, patients trained to interpret ambiguity in a positiveway would interpret new ambiguous information less negativelyand more positively compared to patients in the placebo-controlcondition. Secondly, based on the theoretical model and previousfindings in high anxious individuals, it was predicted that patientsin the CBM-I condition would display less anxiety, depressivemood, general psychological distress, and more positive moodfollowing training relative to patients in the placebo control con-dition (primary outcome) and that those treatment effects wouldbe maintained at follow-up. In order to clarify the unexpected re-sults of the first study (see below), we performed a second studywith a different placebo control condition.

2. Study 1

2.1. Participants

The waiting list at Altrecht Academic Anxiety Centre or MesosMedical Centre (Utrecht, the Netherlands) was searched to identifypatients who had, based on the intake procedure, one of thefollowing diagnoses: PD with or without agoraphobia; SAD; PTSD;

or GAD. Eligible participants received a detailed letter describingthe study, the aim (to examine the effect of a computerised trainingfor anxiety), randomisation, the assessments, the risks etc., andinviting them to participate. Patients were subsequently contactedby the research team (the first author or a trained research assis-tant) by telephone to answer any questions and, when interested,to arrange a face-to-face assessment to determine Axis I diagnosisusing the Structured Clinical Interviews for the DSM-IV, version I(SCID; First, Spitzer, Gibbon, & Williams, 1996; van Groenestijn,Akkerhuis, Kupka, Schneider, & Nolen, 1999). All participants gavewritten informed consent to participate.

Inclusion criteria were: 1) age above 18, and 2) one of thefollowing diagnoses: PD with or without agoraphobia; SAD; PTSD;or GAD. Exclusion criteria were: 1) concurrent psychologicaltreatment, 2) no access to internet, 3) insufficient Dutch literacy, 4)current psychosis, or 5) current substance/alcohol dependence.There were no exclusion criteria with respect to other Axis I or IIdiagnoses. Patients prescribed psychotropic medication needed tobe taking a constant dose for at least two weeks before study entryand remaining stable throughout the study to reduce the likelihoodthat recent medication change could account for symptomimprovement.

The trial CONSORT flowchart (Fig. 1) describes the flow of po-tential participants assessed for eligibility through to random-isation either to the positive CBM-I (n ¼ 24) or the placebo controlgroup (n ¼ 23). In total, 18 patients in the positive and 18 in theplacebo-control condition successfully completed the eight-dayprocedure. As a main diagnosis, fourteen patients met diagnosticcriteria for PDwith or without agoraphobia, eight patients met GADcriteria, six SAD, six PTSD, and two agoraphobiawithout a history of

E. Salemink et al. / J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195 189

panic disorder. On average, participants had 2.3 (SD ¼ 1.0) Axis Idiagnoses and co-morbid diagnoses consisted of another anxietydisorder, depressive disorder (current or in remission), hypochon-driasis, body dysmorphic disorder, or binge-eating disorder. Due totechnical difficulties, five participants did not receive the post-program recognition test (CBM-I condition n ¼ 1 and control con-dition n ¼ 4). Six participants did not return the follow-up ques-tionnaires (CBM-I condition n ¼ 4 and control condition n ¼ 2),resulting in follow-up data for 14 patients in the positive CBM-Icondition and 16 patients in the placebo-control condition.

2.2. Design

Participants meeting the entry criteria were randomly allocated1:1 (carried out within the online computer program) to the pos-itive CBM-I training versus the control condition. Patients and re-searchers were blind to condition (double blind design). Data werecollected at baseline assessment before randomisation, during thetraining, directly after the training, and at three months aftercompletion of the training. G*Power was used to calculate samplesize. The study was approved by the medical ethics committee ofthe University Medical Centre Utrecht, the Netherlands. Datacollection was carried out from November 2006 to January 2008.

2.3. Materials

2.3.1. Positive Cognitive Bias Modification of InterpretationsTo modify interpretation bias, patients were trained for eight

sessions at home over the internet (Salemink et al., 2009). In eachsession, participants received 104 unique scenarios presented ineight blocks with optional rests between each block. Scenarios thatwere used successfully in previous studies (Mathews & Mackintosh,2000; Salemink, van denHout, & Kindt, 2007, 2009) were adapted toreflect situations relevant for a non-student, clinical population. Eachblock contained eight modification scenarios, three neutral fillerscenarios, and two probe assessment scenarios (see InterpretationBias OutcomeMeasurements), all presented in a fixed randomorder.

The modification scenarios consisted of three lines that wereambiguous in terms of valence. Aword fragment disambiguated thescenario in a positive way. Participants were asked to complete thefragments as quickly as possible and the complete word was pre-sented subsequently. A comprehension question with relevantfeedback appeared on the screen to consolidate the interpretationimposed by the word fragment. An example is:

You have just moved to a new area and your neighbour asks if youwould like to go to the local pub that evening. When youarrive, they are not yet there. After your earlier conversation,they probably thought you were .likeab-e (likeable)

Did you make a bad impression on your new neighbour?

The ‘neutral filler scenarios’ had no emotional content, nor didthey contain ambiguity. They were inserted to make the trainingless obvious.

2.3.2. Placebo control conditionThe difference between the positive CBM-I condition and the

placebo control condition is that the latter group received fourpositive and four negative scenarios instead of eight positive sce-narios within each block.

2.3.3. Interpretation bias outcome measurementsTo check whether CBM-I was successful in modifying interpre-

tation bias, two interpretation bias outcome measures were

obtained. The first is the latency to complete probeword fragments.Probe scenarios were comparable to the emotional scenarios, butthey had a fixed positive and negative valence, irrespective ofcondition. They were inserted to measure the speed of resolvingword fragments of positive and negative valences across thetraining phase (Mathews & Mackintosh, 2000; Salemink et al.,2007, 2009). A more positive interpretation style is expected tofacilitate finding solutions for the positive word fragments andimpede finding solutions for the negative word fragments.

The second interpretation bias outcome measure was therecognition task that consisted of ten new ambiguous scenarios(Mathews & Mackintosh, 2000; Salemink & van den Hout, 2010). Inthis task, solution of the word fragments did not disambiguate thescenario; the scenario remained ambiguous. An example is pre-sented here:

The evening class

You’ve just started going to an evening class. The instructor asks aquestion and no one in the group volunteers an answer, so he looksdirectly at you. You answer the question, aware of how your voicemust sound to the .

oth–s (others)

Have you been going to the evening class for a long time?

In the second part of the recognition test, participants saw thetitle of the ambiguous scenario, together with four sentences pre-sented in a random order. These sentences represented a) apossible positive interpretation, b) a possible negative interpreta-tion, c) a positive foil sentence, and d) a negative foil sentence. Thefour corresponding sentences of “The evening class”-scenario arepresented here:

a) You answer the question, aware of the others listeningattentively.

b) You answer the question, aware of how unsteady your voicesounds.

c) You answer the question and then realise what a goodanswer it is.

d) You answer the question, but realise that you have made amistake.

Participants rated each sentence for its similarity in meaning tothe original scenario using a 4-point scale ranging from 1 (verydifferent in meaning) to 4 (very similar in meaning).

2.3.4. Emotional outcome measurementsFour self-report measures were administered three times:

Assessment 1 (before the start of the training), Assessment 2 (aftercompleting all eight sessions), and Assessment 3 (at follow-up:approximately three months after training). The Dutch version ofthe State-Trait Anxiety Inventory (STAI-ST, Spielberger, Gorsuch,Lushene, Vagg, & Jacobs, 1983; Van der Ploeg, Defares, &Spielberger, 2000) was administered to measure state and traitanxiety. This four-point scale self-report questionnaire contains 40items and has adequate psychometric properties. To measure levelof depressive symptoms, the widely used and well-validated BeckDepression Inventory (BDI, Beck, Rush, Shaw, & Emery, 1979) wasused. It is a 21-item self-report questionnaire with good psycho-metric properties. A third measure was the Dutch translation of theSymptom CheckList-90 (SCL-90; Arrindell & Ettema, 1986;Derogatis, 1977). It comprises 90 items and answers are given ona five-point scale. The total score was used as a measure of generalpsychological distress. The internal consistency of this score issatisfactory. Fourth, positive and negative affect wasmeasuredwith

Table 1Socio-demographic and clinical characteristics of participants Study 1.

PositiveCBM-I group(n ¼ 18)

50%/50%control group(n ¼ 18)

Statistic p-Value

Age, mean (SD) 41.9 (9.5) 38.6 (10.8) t ¼ �.97 .34Women 15 11 c2 ¼ 2.22 .26Marital statusSingle 2 2Relationship,not cohabitating

0 3

Cohabitating 6 5 c2 ¼ 5.49 .24Married 4 6Divorced 6 2

Education: exams passedUniversity e graduate level 2 2University e undergraduatelevel

3 5

High school 1 0 c2 ¼ 1.9 .75Middle school 10 8Elementary school 2 3

No. of Axis I diagnoses,mean (SD)

2.0 (1.1) 2.5 (.9) t ¼ 1.53 .13

Duration of diagnoses,mean (SD), in years

14.9 (12.7) 15.7 (10.8) t ¼ .20 .84

Years of treatment, mean (SD) 1.7 (2.4) 1.3 (1.6) t ¼ �.70 .49Psychotropic medication use 8 14 c2 ¼ 4.21 .09

Note. Data is given as number of individuals, except where is indicated that data isgiven as means with standard deviation in parentheses.

E. Salemink et al. / J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195190

the psychometrically sound Positive and Negative Affect Schedule(PANAS, Watson, Clark, & Tellegen, 1988). This scale consists of 20words that describe different feelings and emotions and partici-pants indicated on a five-point scale to what extent they felt thatway.

2.3.5. Exit interviewAn exit interview was conducted to obtain participants’ ideas

regarding their allocated condition (positive vs. placebo-control).They were asked to indicate which condition they thought theyhad followed. If they had no idea, they were invited to guess.

2.4. Procedure

During the first assessment session, participants completed theself-report questionnaires. As a next step, participants were told toimagine themselves being in the situations described in the sce-narios and completed ten practice trials in the presence of theexperimenter. Afterwards, the experimenter left and the partici-pant could complete the first session individually at the time thatsuited him/her best.

Participants completed the subsequent sessions at home overthe internet and the experimenter received an automaticallygenerated e-mail confirmation when a session was successfullycompleted by a participant. Each session started with some in-structions on creating a quiet and undisturbed test environment.Then participants could start with the scenarios.1 The duration ofeach session was approximately 45 min. Participants had to com-plete eight sessions in a period of 11 days and were allowed toinclude three training free days. Directly after the last block oftraining on the eighth day, participants received the recognitiontask. Assessment II was planned within three days following the

1 Participants’ daily positive and negative mood states were assessed beforeevery session with three positive and three negative items from the PANAS. Thesedaily measurements were not reported, as we focused on the pre-, post-, andfollow-up assessments.

cessation of the program. Again the experimenter visited the pa-tient at home and they completed the questionnaires. Afterwards,an exit interview took place. Assessment III was by mail atapproximately three months follow-up. By that time patients werereceiving treatment as usual, thus limiting conclusions based onthe follow-up assessments. Participants did not receive compen-sation for screening, assessments nor participating in the study;they only received a small financial reimbursement for theirinternet costs.

2.5. Results Study 1

2.5.1. Between-group differences at baselineComparison of the two conditions at baseline (Table 1) revealed

no significant group differences regarding age, sex, marital status,educational level, number and duration of diagnoses, duration oftreatment, or psychotropic medication use. Furthermore, thegroups did not differ significantly on the pre-assessment ques-tionnaires (see Table 2), except for the STAI state questionnaire,t(34) ¼ 2.11, p < .05. That is, before starting the program, partici-pants in the control group felt more anxious than participants inthe positive condition. As these scores were related to the negativescale of the PANAS and the follow-up assessment (and not tochanges from T1 to T2 in reaction time data, recognition task, traitanxiety, SCL-90, BDI, and PANAS positive scale), these pre-assessment state anxiety scores were added as a covariate to thePANAS negative scale and follow-up analyses.

2.5.2. Interpretation bias outcome measuresRegarding the latency to complete probe fragments, reaction

time trials where an incorrect response was given to the fragmentcompletion (3.9%) or to the comprehension question (6.1%) wereomitted from the analysis. In addition, latencies were set aside ifthe latency was less than 200 ms (0.04%) or greater than three SDsabove the individual mean (1.7%). A mixed model ANOVA2 withCMB-I group (positive vs. control) as the between-subjects factorand probe (positive vs. negative) as the within-subject factor wasconducted to test the effectiveness of the online CBM-I in changinginterpretations. There was a significant main effect of probe, F(1,34) ¼ 32.63, p < .001, hp2 ¼ .49, that was qualified by a significantGroup� Probe interaction effect, F(1, 34)¼ 21.53, p< .001, hp2 ¼ .39.While, therewas no significant difference in responding to negativeand positive probes in the control group, t(17) ¼ �0.72, p ¼ .48(Mnegative probes ¼ 1470 ms, SD ¼ 557, Mpositive probes ¼ 1447 ms,SD¼ 539), participants who had been exposed to the positive CBM-I training displayed a marked slowing in reacting to negative(M ¼ 1852 ms, SD ¼ 507) as compared to positive probes(M ¼ 1635 ms, SD ¼ 433), t(17) ¼ �7.80, p < .001. Furthermore,directly comparing both groups using independent samples t-testindicated that positively trained patients were significantly slowerin responding to negative probes, t(34) ¼ �2.15, p < .05.

The second interpretation bias outcome measurement was therecognition test. A mixed model ANOVA2 with group as thebetween-subjects factor and valence (positive vs. negative) andtarget (possible interpretation vs. foil sentence) as the within-subject factors was performed. In addition to a significant maineffect of valence, F(1, 29) ¼ 50.40, p < .001, hp2 ¼ .64, and target, F(1,29) ¼ 55.47, p < .001, hp2 ¼ .66, the analysis revealed a significantGroup � Valence interaction effect, F(1, 29)¼ 6.58, p< .05, hp2 ¼ .19.Both the positively trained and control trained participants gavehigher similarity ratings to positive than to negative

2 An intention-to-treat analysis with last observation carried forward revealedthe same pattern of results.

Table 2Mean scores of the outcome measures (SD in parentheses) for the positive and 50%/50% placebo control group (Study 1).

Positive CBM-I group (n ¼ 18) 50%/50% control group (n ¼ 18)

Pre-assessment Post-assessment Within-groupeffect sizea

FU (n ¼ 14) Pre-assessment Post-assessment Within-groupeffect sizea

FU (n ¼ 16)

STAI state 40.6 (13.5) 41.1 (10.1) �0.04 44.6 (12.2) 48.8 (9.6) 49.7 (12.3) �0.08 51.8 (12.3)STAI trait 50.7 (12.5) 46.7 (10.1) 0.35 46.0 (10.1) 54.3 (10.1) 52.3 (9.9) 0.20 51.7 (12.1)BDI 17.2 (9.4) 12.9 (8.3) 0.49 13.4 (10.6) 20.0 (10.6) 17.4 (12.2) 0.23 14.9 (12.6)SCL-90 190.6 (61.4) 177.8 (62.5) 0.21 179.7 (70.9) 207.5 (53.1) 187.3 (56.9) 0.37 187.3 (61.3)PANAS PA scale 29.2 (9.3) 28.4 (8.1) 0.09 32.2 (8.5) 24.8 (7.9) 25.1 (9.1) �0.04 23.3 (8.6)PANAS NA scaleb 18.3 (8.1) 17.1 (6.7) 0.16 18.9 (8.0) 21.7 (7.9) 20.9 (6.7) 0.11 20.3 (8.2)

21.2 adj. M 19.0 adj. M 20.7 adj. M 20.1 adj. M 18.8 adj. M 18.6 adj. M

Note. FU ¼ follow up. PA ¼ positive affect and NA ¼ negative affect.a Within-group pre- to post-training effect sizes ¼ (pre-assessment mean - post-assessment mean)/pooled standard deviation.b As the difference in state anxiety before the eight day program was related to change in PANAS negative scale, we also report adjusted means (adj. M).

E. Salemink et al. / J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195 191

interpretations, t(16) ¼ 6.34, p < .001 and t(13) ¼ 3.81, p < .01respectively, but this was more marked in the positive CBM-I group(Mpositive interpretations ¼ 2.58, SD ¼ 0.42 vs. Mnegative

interpretations ¼ 1.71, SD ¼ 0.50) than in the control group (Mpositive

interpretations ¼ 2.42, SD ¼ 0.42 vs. Mnegative interpretations ¼ 2.01,SD ¼ 0.33). Note that training effects did not interact with Targettype. This suggests that more general mechanisms might beinvolved such as emotional priming with CBM-I increasing theaccessibility of an entire category of emotionally positive materialor that general positive responses were trained.

2.5.3. Clinical outcomes and moodTable 2 gives means and standard deviations of the clinical as-

sessments for the positive CBM-I and placebo control group. A two-way mixed model ANOVA2 with group (positive CBM-I vs. controlcondition) as the between-subjects factor and time (before vs.directly after) as the within-subject factor was performed on theclinical outcome measures. To examine the stability of the effects onthe clinical measures, a subsequent two-way ANCOVA2 was con-ducted with group as the between-subjects factor and time (post-assessment vs. three-months follow-up) as the within-subject factorand pre-assessment state anxiety scores added as a covariate.

Regarding effects on trait anxiety, a significant main effect oftime appeared, F(1, 34) ¼ 6.08, p < .05, hp2 ¼ .15. Irrespective ofgroup assignment, trait anxiety scores decreased from pre- to post-assessment. The predicted Group � Time interaction effect was notsignificant, F(1, 34)¼ 0.63, p ¼ .43, hp2 ¼ .02. Analysis of the stabilityof the reduction of trait anxiety revealed no significant effectsregarding the factors Group and Time, F’s (1, 27) < 0.32, p’s > .58,hp2’s < .01, indicating that there was no significant change in trait

anxiety from post-assessment to follow-up.The predicted interaction effect of group by time was also not

significant for state anxiety scores, F(1, 34) ¼ 0.01, p ¼ .98, hp2 < .001.That is, thepositive andcontrol conditiondidnotdiffer significantly inchange of state anxiety. A significant main effect of group wasobserved, F(1, 34)¼6.38,p< .05,hp2¼ .16with thecontrol groupbeingmore state anxious than the positive CBM-I group. No significant ef-fects regarding the factors Group and Timewere observed from post-assessment to follow-up, F’s (1, 27) < 1.32, p’s > .26, hp2’s < .05.

Regarding effects on depression, a significant main effect of timeappeared, F(1, 34) ¼ 15.05, p < .001, hp

2 ¼ .31, indicating lessdepressive symptoms following the eight day program. This wasnot qualified by a significant Group � Time interaction effect, F(1,34) ¼ 0.93, p ¼ .34, hp2 ¼ .03. No significant effects regarding thefactors Group and Time were observed from post-assessment tofollow-up, F’s (1, 27)< 1.35, p’s> .26, hp2’s < .05, suggesting that thedecrease in depressive symptoms was maintained at follow-up.

For levels of psychological distress (SCL-90), analyses revealed asignificant main effect of time, F(1, 34) ¼ 10.35, p < .01, hp2 ¼ .23,

reflecting a general decrease in psychopathological symptoms,irrespective of group. No other effects were significant, includingthe predicted Group � Time interaction effect, F(1, 34) ¼ 0.53,p ¼ .47, hp2 ¼ .02. There were no significant effects regarding thefactors Group and Time from post-assessment to follow-up, F’s (1,27) < 0.25, p’s > .62, hp2’s < .009.

Analyses of the PANAS positive subscale data revealed no signifi-cant effects, including the Group � Time interaction effect, F(1,34)¼ 0.15,p¼ .70, hp2¼ .004. Examination of change inpositivemoodfrom post-assessment to follow-up revealed no significant effectsregarding the factors Group and Time, F’s (1, 27) < 02.66, p’s > .12,hp2’s < .09. The scores on PANAS negative subscale were entered into

an ANCOVA with pre-assessment state anxiety as a covariate. Theassumption of homogeneity of regression slopeswasmet and resultsrevealed a significant main effect for the covariate, F(1, 33) ¼ 11.88,p < .01, hp2 ¼ .27, reflecting a positive relationship between pre-assessment state anxiety and negative mood state. No other resultswere significant, including the Group � Time interaction effect, F(1,33) ¼ 0.75, p ¼ .39, hp2 ¼ .02, thus showing that the groups did notdiffer significantly in change in negative mood state. No significantchanges were observed regarding the factors Group and Time frompost-assessment to follow-up, F’s (1, 27)< 0.51, p’s > .48, hp2’s < .02.

2.5.4. Exit interviewAnalysis of the results from the exit interview revealed that

therewas no difference between the groups in their ideas about thetreatment they had received, c2(1, N ¼ 35) ¼ 0.24, p ¼ .71. Fiveparticipants in the positive CBM-I and four in the control groupthought they had followed the positive CBM-I condition. As a nextstep, it was examined whether their belief about the receivedtraining was related to the dependent variables by adding thisvariable as a covariate to the analyses. Results showed that such abelief was neither related to the interpretation bias measures (re-action times, F(1, 32)¼ 0.02, p¼ .90, hp2 ¼ .001; recognition task, F(1,27)¼ 0.10, p¼ .75, hp2 ¼ .004), nor to the dependentmood variables,F’s (1, 32) < 1.72, p ¼ .20, hp2 ¼ .05.

2.6. Discussion of Study 1

Study 1 revealed that after an online eight-day CBM-I trainingprogram to interpret ambiguous information in a more positivemanner, patients interpreted new ambiguous information lessnegative than patients who had received the placebo-control con-dition. While the interpretation bias data revealed the predicteddifferences between the two groups, we observed no difference be-tween the two groups in reported change in emotions. Both groupsshowed a decrease in trait anxiety, depressive mood, and psycho-logical distress irrespective of the training. This decrease was main-tained at follow-up. The finding that both groups showed significant

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reductions in self-reported symptoms with no superiority for theCBM condition has also been observed in other CBM studies (Amir &Taylor, 2012; Beard & Amir, 2008; Boettcher, Berger, & Renneberg,2012; Carlbring et al., 2012). A post-hoc explanation for the changein symptoms is the role of general non-specific factors (support fromresearchers, participating in an academic clinical study, regression tothemean, hopeof improvement, etc.);non-specific factors account. Analternative possibility is that not only the positive CBM-I training, butalso the 50%/50% placebo-control condition has led to more positiveinterpretations and as a consequence to reductions in anxiety,depression, and psychological distress. At post-assessment, bothgroups made more positive than negative interpretations (thoughthiswasmoremarked in thepositive group). Aspatientswith anxietydisorders have a tendency to interpret ambiguous situations nega-tively (Ouimet, Gawronski, & Dozois, 2009), it seems likely that theystarted the experiment with a negative interpretation bias. Supposethat they are naturally inclined to interpret 90% of the ambiguousscenarios negatively. The “control” condition consisted of 50% posi-tive and 50% negative interpretations andmight thus have served todisconfirm spontaneous negative interpretations and enhance posi-tive interpretations. Patients might have learnt that, at least in thepresent context, positive outcomes of ambiguous scenarios aremorecommon than assumed. Thus, an alternative explanation (dilutedtraining account) is that the50%/50%placebo-control conditionmighthave functioned as a diluted version of training resulting in morepositive and less negative interpretations and, as a consequence, inreduced levels of anxiety, depression, and psychological distress. Totest this possibility and clarify the findings of Study 1, an additionalstudy was conducted.

3. Study 2

3.1. Introduction

Study 2 was designed to clarify the findings of Study 1 and toevaluate two alternative explanations (diluted training account versusnon-specific effects account). This study consisted of a 100% neutralcontrol condition that resembled the two previous conditions in thatparticipants read short scenarios and completed word fragments andcomprehensionquestions.However, this time, the scenariosdescribedneutral, non-emotional situations and no valenced interpretationswere to be generated. We therefore expected that interpretationswould remain unaffected in this 100% neutral condition.

Table 3Sociodemographic and clinical characteristics of participants Study 2.

Neutral placebo controlgroup n ¼ 19

Age, mean (SD) 33.4 (9.3)Women 11Marital statusSingle 6Relationship, not cohabitating 1Cohabitating 8Married 3Divorced 1

Education: exams passedUniversity e graduate level 6University e undergraduate level 2High school 1Middle school 10Elementary school 0

No. of Axis I diagnoses, mean (SD) 2.1 (1.0)Duration of diagnoses, mean (SD), in years 8.1 (6.6)Years of treatment, mean (SD) 2.2 (2.9)Psychotropic medication use 13

Note. Data is given as number of individuals, except where is indicated that data isgiven as means with standard deviation in parentheses.

When directly comparing the results from the neutral group tothe positive CBM-I and 50%/50% control condition from Study 1,different predictions were formulated based on the two alternativeaccounts. According to the diluted training account, participantswho received the neutral control condition would interpret ambi-guity more negative and less positive compared to Study 1’s posi-tive CBM-I and 50%/50% condition. Furthermore, participants fromthis neutral control group would feel more anxious, depressed, anddistressed than participants from Study 1’s groups. Alternatively,according to the non-specific effect account, participants from theneutral control group would e just like the 50%/50% group e

interpret ambiguity more negatively and less positively than par-ticipants from the positive CBM-I group and no differences be-tween the groups could be expected on emotional outcomes.

3.2. Participants

Patients were recruited at Altrecht Academic Anxiety Centre,Utrecht, the Netherlands. The inclusion and exclusion criteria forStudy 2 were the same as for Study 1 as well as the criteriaregarding psychotropic medication.

In total, 23 patients were allocated to the neutral condition. Tenpatientsmet diagnostic criteria for PDwith orwithout agoraphobia,six met diagnostic criteria for SAD, two for GAD, and one for PTSD.On average, participants had 2.1 (SD¼ 1.0) Axis 1 diagnoses and co-morbid Axis 1 diagnoses consisted of other anxiety disorders,depressive disorders (either current or in remission), trichotillo-mania, and ADHD. One participant did not receive the intervention,as he/she decided to stop directly after the pre-training assessment.Three participants were lost during training, resulting in 19 patientswho successfully completed the neutral condition. Two participantsdid not return the follow-up questionnaires, resulting in a sample of17 patients for the follow-up data.

3.3. Design

All participants were allocated to the neutral control condition.Data were collected at the same time points as in Study 1. Themedical ethics committee approved this second study and datacollection was carried out from May 2008 to January 2010.

3.4. Materials

Participants in the neutral condition received the same numberof scenarios as participants in Study 1. However, in this condition nopositive or negative emotional scenarios were presented, except forthe probes scenarios. The neutral scenarios consisted of the fillerscenarios from Study 1 and newly created neutral scenarios. Anexample is:

You arrange to meet a friend at your local pubone evening. As you arrive, you cannot help noticingthat the sign in front has been .

pa-nt-d (painted)

Has your pub changed it appearance?

Themanipulation checks, outcomemeasurements, exit interviewand experimental software were identical to the ones in Study 1.

3.5. Results Study 2

3.5.1. Between-group differences at baselineWhen comparing sociodemographic characteristics between

the neutral control group from Study 2 and the positive CBM-I and

E. Salemink et al. / J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195 193

control group from Study 1, no significant differences in sex, maritalstatus, and educational level appeared (Table 3). However, groupsdiffered significantly in age, F(2, 55) ¼ 3.54, p < .05, hp2 ¼ .12; par-ticipants who had followed the neutral control group were signif-icantly younger than participants why followed the positive CBM-Itraining (the two control groups did not differ significantly). Thethree groups did not differ in number or duration of Axis 1 di-agnoses, nor in years of treatment or psychotropic medication use.Furthermore, participants in the three groups did not differsignificantly for scores on the pre-assessment questionnaires.

3.5.2. Interpretation bias outcome measuresLatencies to complete probe trials were again set aside if the

response to the fragment (1.7%) or the corresponding comprehen-sion question (2.9%) was incorrect, or if the latency was less than200 ms (0%) or greater than three SDs above the individual mean(1.9%). A paired samples t-test revealed that that individuals in theneutral control group did not differ significantly in their responsesto positive and negative probes, t(18) ¼ �0.21, p ¼ .98 (Mpositive

probes ¼ 1457, SD ¼ 569 vs. Mnegative probes ¼ 1457, SD ¼ 546). A 3(Group)� 2 (Probe) Repeated Measures ANOVA2 was conducted onthe reaction time data to examine the CBM-I effects on interpre-tation bias. The significant main effect of Probe, F(1, 52) ¼ 23.9,p < .001, hp2 ¼ .32, was qualified by a significant Group � Probeinteraction effect, F(2, 52) ¼ 17.6, p < .001, hp2 ¼ .40. While the twocontrol conditions did not differ significantly from each other inresponding to positive, t(35) ¼ �0.05, p ¼ .96, or negative probes,t(35) ¼ 0.07, p ¼ .94, both groups differed significantly from thepositive CBM-I group in responses to negative probes, t’s > 2.15,p’s < .05. That is, the positive CBM-I group was disproportionatelyslow in responding to negative probes.

A 3 (Group) � 2 (Valence: positive vs. negative) � 2 (Target:possible interpretation vs. foil sentence) Repeated MeasuresANOVA2 was conducted to examine the effects on the secondinterpretation bias measure, the recognition task. A significantmain effect of Valence, F(1, 47) ¼ 67.9, p < .001, hp2 ¼ .59, and ofTarget, F(1, 47) ¼ 93.6, p < .001, hp2 ¼ .67, was found. In addition, asignificant Group � Valence interaction effect, F(2, 47) ¼ 5.9,p < .01, hp2 ¼ .20, was observed. Follow-up analyses revealed thatthe two control conditions did not differ in their endorsement ofpositive, t(31) ¼ 0.17, nor negative interpretations, t(31) ¼ �0.07(neutral condition: Mpositive interpretations ¼ 2.39, SD ¼ 0.38 vs. Mne-

gative interpretations¼ 2.02, SD¼ 0.31), while both groups differed fromthe positive CBM-I training in endorsement of negative in-terpretations (neutral group: t(34) ¼ 2.22, p < .05; 50%/50% group:t(29) ¼ 1.90, p ¼ .06). That is, patients who had followed the pos-itive CBM-I training gave lower similarity ratings to the negativeinterpretations than patients from the two control groups. In sum,both control groups are comparable regarding their interpretations

Table 4Mean scores of the outcome measures (SD in parentheses) for the neutral placebocontrol group (Study 2).

Neutral placebo control group (n ¼ 19)

Pre-assessment Post-assessment Within-groupeffect sizea

FU (n ¼ 17)

STAI state 48.9 (13.2) 46.2 (12.4) 0.21 46.6 (14.9)STAI trait 52.2 (7.7) 49.5 (9.2) 0.32 47.9 (12.2)BDI 18.7 (8.5) 18.6 (10.5) 0.01 15.3 (12.4)SCL-90 190.2 (42.8) 180.1 (48.7) 0.22 174.0 (72.5)PANAS PA scale 24.2 (6.5) 25.7 (7.2) �0.22 26.6 (9.1)PANAS NA scale 24.6 (7.2) 17.7 (6.5) 1.01 20.2 (8.0)

Note. FU ¼ follow up. PA ¼ positive affect and NA ¼ negative affect.a Within-group pre- to post-training effect sizes ¼ (pre-assessment mean - post-

assessment mean)/pooled standard deviation.

of ambiguity, and the positively trained CBM-I group interpretedambiguity less negatively.

3.5.3. Clinical outcomes and moodTo examine the effects on the clinical measures, 3 (Group) � 2

(Time) Repeated Measures ANOVA2’s were conducted, first withthe within-subject factor time consisting of pre- versus post-assessment scores, and second with this factor consisting of post-assessment versus three-months follow-up scores (Table 4).

Analyses of trait anxiety scores revealed a significant main effectof time (T1 vs. T2), F(1, 50) ¼ 9.68, p < .01, hp2 ¼ .16. Irrespective ofgroup, therewas a decline in trait anxiety scores. The Group� Timeinteraction effect was not significant, F(2, 50) ¼ 0.38, p ¼ .69,hp2 ¼ .02, and there were no significant effects when analysing trait

anxiety scores from post-assessment to follow-up, F’s < 1.83,p’s > .17, hp2’s < .08. Analyses of state anxiety scores revealed nosignificant effects, including the Group � Time (T1 vs. T2) interac-tion effect, F(2, 52) ¼ 0.67, p ¼ .52, hp2 ¼ .03, and T2 vs. T3 analyses,F’s < 1.89, p’s > .16, hp2’s < .08.

Depression scores decreased significantly from pre- to post-assessment (main effect Time, F(1, 52) ¼ 9.19, p < .01, hp2 ¼ .15)and this did not differ significantly between the groups(Group� Time interaction effect was not significant, F(2, 52)¼ 2.54,p ¼ .09, hp2 ¼ .09). No significant effects emerged when comparingpost-assessment to follow-up depression scores, F’s < 2.0, p’s > .17,hp2’s < .04.For levels of psychological distress (SCL-90 scores), the pattern

of results was comparable to the pattern in trait anxiety anddepression. That is, a significant main effect of Time (T1 vs. T2) wasobserved, F(1, 50)¼ 15.2, p < .001, hp2 ¼ .23, indicating a decrease inlevel of distress, irrespective of group. This effect was not qualifiedby a significant Group � Time interaction effect, F(2, 50) ¼ 0.57,p ¼ .57, hp2 ¼ .02. There were no significant effects from post-assessment to follow-up, F’s < 1.23, p’s > .30, hp2’s < .06.

Analyses of the pre- and post-assessment scores on the PANASpositive scale revealed no significant effects, including theGroup � Time interaction effect, F(2, 52) ¼ 0.43, p ¼ .65, hp2 ¼ .02.A significant main effect of group emerged when examining post-assessment scores to follow-up scores, F(2, 44) ¼ 3.63, p < .05,hp2 ¼ .14; patients who had followed the positive CBM-I training

felt more positive at post and follow-up assessment than patientswho had followed either control condition. Regarding negativemood (PANAS negative scale), a significant main effect of Time wasobserved, F(1, 52) ¼ 13.5, p ¼ .001, hp2 ¼ .21, that was qualified by asignificant Group � Time interaction effect, F(2, 52) ¼ 5.9, p < .01,hp2 ¼ .19. There was a general decrease in negative mood and the

strongest reduction occurred in the neutral control group. Nosignificant effects emerged when analysing negative moodscores from post-assessment to follow-up, F’s < 0.47, p’s > .63,hp2’s < .02.

3.6. Discussion

Study 2 consisted of a 100% neutral control group to clarify theunexpected findings of Study 1 and to test two alternative expla-nations. We clearly found that the neutral control condition fromStudy 2 resembled the control condition from Study 1 in bothinterpretation style and changes in emotionality, thus providingsupport for the non-specific factors account.

4. General discussion

The aim of the current studies was to examine the therapeuticeffectiveness of an internet-based CBM-I training in a clinicalsample of patients with a broad range of anxiety disorders. Study 1

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compared an eight-day positive CBM-I training with a placebocontrol condition. As predicted, individuals who received the pos-itive CBM-I training interpreted ambiguous situations less negativecompared to individuals who received the control condition. Thissuggests that the online training was successful in modifying in-terpretations, however, as there was no pre-training assessment ofinterpretive bias, the actual change in interpretive bias cannot bedetermined in the current study. Though note, that the observedpost-training difference in interpretive bias was consistent withlab-/office-based studies revealing the pre- to post-CBM-I trainingchange in interpretive bias in clinical samples (Amir & Taylor, 2012;Brosan et al., 2011). The current study is the first to examine CBM-Ieffects on interpretations using online training and across a rangeof different anxiety disorders, and the findings are suggestive, butnot conclusive, of CBM-I affecting interpretations.

Furthermore, we observed reductions in anxiety, depression,and psychological distress. This was, however, irrespective of groupassignment. Thus in contrast to our hypothesis regarding emotionaloutcomes, there was no superior improvement in emotionality inthe positive CBM-I condition. While this finding was unexpectedbased on the theoretical model and findings in analogue samples, itis, however, consistent with findings from some other CBM studiesthat also observed improvements in self-reported emotions in thecontrol condition and no difference between the CBM and controlgroup (Amir & Taylor, 2012; Beard & Amir, 2008; Boettcher et al.,2012; Carlbring et al., 2012). We hypothesised that, in the currentstudy, this could be due to general non-specific factors (non-specificfactors account), but could also be due to the 50%/50% placebocontrol condition promoting more positive interpretations in theclinical sample (diluted training account). Therefore, a second study,consisting of a neutral control group, was designed to clarify Study1’s findings and test both accounts. It revealed that the 100% neutralcontrol condition resembled the pattern of data from Study 1’scontrol condition, thus ruling out the possibility that the emotionalimprovement in Study 1 was due to changes in interpretation bias(diluted training account). Instead, other factors might have pro-duced the effects on emotionality. Such factors might be related tothe study (e.g., positive expectations arising from participation inan academic research project, support and attention from theresearcher, demand effects, placebo expectation effects), but mightalso be independent of the study (e.g., spontaneous remission,expectation of the coming treatment as usual, regression to themean). To disentangle these two types of factors, future studiesshould include an assessment-only control condition as this wouldprovide information regarding the effects of being on a waiting list.

The fact that in the current study CBM-I training was offeredonline might have influenced the results as well. Note that it isunlikely that this fully explains the current findings, as our onlineCBM-I training seem to have affected interpretations, and there areoff-line CBM studies that also failed to observe superior effects ofCBM on self-reported anxiety and depression symptoms (Amir &Taylor, 2012; Beard & Amir, 2008; Hayes et al., 2010). While theadvantage of online (CBM) treatments is reduced barriers for pa-tients who are unable or unwilling to visit a clinic or university, thedisadvantage is less control over the procedures and setting. Astraining is performed at home, it is difficult to ensure a standardtest and training environment. However, when looking at thepercentage of incorrect responses given to the comprehensionquestion, there were no differences between the current study anda lab-based CBM-I training (see Hayes et al., 2010, if anything, thecurrent study had higher accuracy rates). In the same vein, thepresent CBM-I manipulation was superior in changing in-terpretations. It appears, therefore, that the fact that the trainingwas internet-delivered is an unlikely explanation for the lack ofdifferences between the experimental and control groups.

The current pattern of findings is in contradictionwith cognitivemodels of psychopathology (Beck et al., 1985; Williams et al., 1988).In these models, it is argued that the tendency to interpret ambi-guity in a negative way is causally related to anxiety. The observeddifference between the experimental condition and the controlgroups in interpretive bias following training should, based onthese models, be associated with concomitant change in anxiety.However, in the current study, no effect on anxiety and otheremotional measures were observed over and above the effects ofthe control groups. Evidently, future studies are necessary toexamine the robustness of these findings. If they are replicated, thisshould lead to a critical evaluation of the explanatory value of thoseearly cognitive models (Beck et al., 1985; Williams et al., 1988). Thiscould be accompanied by examining other factors that might play arole. Note that more recent cognitive theories (Mathews &Mackintosh, 1998) argue that not only bottom-up emotional acti-vation (threat-evaluation system), but also top-down regulatorycontrol plays an important role in anxiety (for supporting empiricaldata, see Salemink, Friese, Drake, Mackintosh, & Hoppitt, 2013;Salemink & Wiers, 2012). Based on this, it could be argued thatinterpretive bias only results in anxiety when the activation of theaffective system exceeds the capacity for control. In other words,CBM-I training might be more effective in individuals with lowlevels of regulatory control (see Salemink & Wiers). In summary,future studies are necessary to examine the replicability of thecurrent findings and also test recent theoretical models regardingother cognitive processes, such as regulatory control, in anxiety.

Some study limitations should be acknowledged. The samplesize is relatively small and reduced our ability to draw clear in-ferences about the absence of emotional change in light of thecognitive change. However, it is comparable to sample sizes ofprevious CBM-I studies (Beard et al., 2011; Brosan et al., 2011; Hayeset al., 2010; Mathews & Mackintosh, 2000). A second limitation isthe lack of a baseline assessment of interpretive bias. Future studiesshould include a pre-training interpretive bias assessment to beable to examine change in bias. In addition, the study lacks ameasure of credibility and expectancy and including such a mea-sure would be helpful to be able to examine placebo expectationeffects. A third point is related to the stimuli types used (social) andthe current sample (heterogeneous group of anxiety disorder pa-tients). The scenarios were not matched to the specific concerns ofall the patients. This might have affected the results given thecontent specificity of interpretive biases (Clark et al., 1988;Voncken, Bögels, & de Vries, 2003) and might explain why therewas a change in interpretive bias, but not in emotionality(Mackintosh, Mathews, Eckstein, & Hoppitt, 2013). However, asearlier CBM-I studies in anxious individuals suggested that theCBM-I effects were rather general and independent of the preciseconcerns of the individual (Mathews et al., 2007; Salemink et al.,2009), general social scenarios were used in the current study. Itmight, however, be that in clinical populations, it is more importantto have a match between content of the training and the concernsof the population and/or intended emotional change. A fourth pointis related to the temporal separation of the training sessions (seealso Macleod et al., 2009). The current study consisted of eighttraining sessions to be completed in an 11 day period. While such amassed training has shown to impact upon interpretations andemotions (Salemink et al., 2009), other CBM-I studies have usedmore spaced training where participants completed training ses-sions only once or twice per week (Amir & Taylor, 2012; Beard et al.,2011; Brosan et al., 2011). More spaced trainingmight providemoreopportunities to practice the new ways of interpreting informationin real life. A possibility is that in a clinical sample, interpretationscan be modified in eight days, as the current studies revealed, butthat further or more spaced repetition over time is needed to affect

E. Salemink et al. / J. Behav. Ther. & Exp. Psychiat. 45 (2014) 186e195 195

symptoms and emotions. This is an empirical issue and futurestudies might compare massed versus spaced CBM training. Finally,a limitation of the current study is the variability in (not) receivingtreatment as usual (and the type treatment and number ofcompleted sessions) during the follow-up assessment.

In sum, the current randomised controlled trial in patients withanxiety disorders revealed that internet-delivered positive CBM-Itraining was associated with less negative interpretations, howeverit did not outperform the control conditions regarding effects onanxiety, depression, and levels of psychological distress. Report ofthese null findings is important to increase knowledge regarding theeffectiveness of online CBM-I training and reduce file-drawer prob-lems that easily occur with novel and theoretically intriguing in-terventions. CBM-I has been described as a potential new treatmentforanxietydisorders,however, thepresentfindingssuggest thatmoreresearch is necessary before CBM-I training can be disseminated.

Acknowledgements

The work was carried out at the Department of Clinical andHealth Psychology, Utrecht University, the Netherlands. We arevery grateful to the patients of our study. We want to thank NellieBuurman and Erline Rood for their valuable help with patientrecruitment, assessments, and data entry. We thank Saskia Righartand Hellen Hornsveld for their help in patient recruitment atAltrecht Academic Anxiety Centre and Mesos Medical Centre,respectively. Martin Laverman is thanked for his help in developingthe internet-based computer program. This study was not sup-ported by a grant and none of the authors have financial interests todisclose.

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