ORIGINAL PAPER

Guided Internet-Based CBT for Common Mental Disorders

Gerhard Andersson • Per Carlbring •

Brjann Ljotsson • Erik Hedman

Published online: 21 May 2013

� Springer Science+Business Media New York 2013

Abstract The Internet has become a part of most people’s

lives in many parts of the world. Since the late 1990s there

has been an intensive research activity in which psycho-

logical treatments, such as cognitive behavior therapy

(CBT), have been found to be effective when delivered via

the Internet. Most research studies indicate that the effects

are larger when some form of guidance is provided from a

therapist, and unguided treatments tend to lead to more

dropout and smaller effects. Guided Internet treatments

often consists of book length text materials, but can also

include other components such as audio files and video clips.

Homework assignment is often included and feedback is

given for completed homework. Guided Internet-based CBT

(iCBT) has been found to work for problems such as

depression, panic-, social anxiety-, and generalized anxiety

disorders. There are many research trials in which partici-

pants have been recruited via media, and there has been less

research conducted in representative clinical settings. Most

research has been conducted on adults and in university

settings with nationwide recruitment. There is a need for

treatments and studies on older adults, children and ado-

lescents. In conclusion, dissemination of the research find-

ings on guided iCBT to regular clinical settings is warranted.

Keywords Internet � Guided self-help � Mood disorders �Anxiety disorders

Introduction

Internet has become an integral part of our lives and with a

few exceptions a majority of the population in the indus-

trialized countries use the Internet daily to communicate

and share information (www.internetworldstats.com).

Within the field of cognitive behavior therapy (CBT) cli-

nicians and researchers realized early on that the Internet

would be of great importance (Riley and Veale 1999), and

psychological research involving the Internet started by the

end of the 1990s (Barak 1999). A background to the study

of Internet treatment is research on bibliotherapy, i.e.

treatment based on self-help texts, which has been shown

to have beneficial effects in studies on anxiety and mood

disorders (Watkins 2008). In the 1980s computerized

treatments were developed and tested (Marks et al. 1998),

but increasingly the field of self-help interventions has

moved on to do research on Internet-delivered CBT

(iCBT).

In this review paper, we will mainly focus on research

conducted in Sweden, in which guided iCBT has been

around for almost 15 years and the treatment has been

G. Andersson (&)

Department of Behavioural Sciences and Learning, Swedish

Institute for Disability Research, Linkoping University,

581 83 Linkoping, Sweden

e-mail: gerhard.andersson@liu.se

G. Andersson � B. Ljotsson � E. Hedman

Division of Psychiatry, Department of Clinical Neuroscience,

Karolinska Institutet, Stockholm, Sweden

P. Carlbring

Department of Psychology, Stockholm University, Stockholm,

Sweden

B. Ljotsson

Division of Psychology, Department of Clinical Neuroscience,

Karolinska Institutet, Stockholm, Sweden

E. Hedman

Department of Clinical Neuroscience, Osher Center

for Integrative Medicine, Karolinska Institutet,

Stockholm, Sweden

123

J Contemp Psychother (2013) 43:223–233

DOI 10.1007/s10879-013-9237-9

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implemented in regular clinical practice. There is however

also an extensive international research (Hedman et al.

2012b), conducted mainly in Australia, The Netherlands

and Switzerland. This research will be mentioned as long

as it is the same treatment format (i.e., guided iCBT) that

has been tested. We will focus on mild to moderate mental

health problems as defined by the DSM-IV, but given the

extensive overlap between somatic and psychiatric disor-

ders, it is worth mentioning that iCBT also has been found

to be effective in the treatment of medical problems

(Cuijpers et al. 2008). In addition to describing the treat-

ment format we will review efficacy studies (regular

research studies) and effectiveness studies.

Description of the Treatment Format

To begin with, it is important to point out that there are

different forms of Internet treatment, and indeed of iCBT

as well. A first distinction is the difference between ‘‘open

access’’ programs and programs that require identification

(e.g., closed and not open to the public), are preceded by a

diagnostic interview, and careful screening procedures.

There is a blurred distinction between these formats of

Internet treatments, but an increasing amount of research

suggests that the latter form yields large treatment effects

(Andersson 2009), while open applications with no guid-

ance tend to have higher dropout rates and smaller effects

(Christensen et al. 2006a). Open access programs can be

justified because they can reach a large group of individ-

uals at a very low cost, for example to promote smoking

cessation (Munoz et al. 2012), but they may be less suitable

for more severe conditions and when self-reports need to

be supplemented with interviews to obtain an accurate

diagnosis. It is also possible that open Internet-based

treatment applications for severe conditions could be dif-

ficult to combine with high standards of patient safety and

that failure to respond to treatment could discourage the

patient to seek further therapist-guided treatment.

A second distinction is related to the degree of therapist

support when iCBT is given. The providers of open access

programs do usually not offer any guidance and the pro-

grams are often fully automated (Christensen et al. 2006b).

To date, there are clear empirical reasons to provide some

degree of support to clients in iCBT (Hedman et al. 2012b;

Johansson and Andersson 2012; Palmqvist et al. 2007;

Spek et al. 2007), as effects tend to be much larger. For

example, Spek et al. (2007) found that iCBT without

support had a pooled mean effect size of d = 0.24 whereas

iCBT with support had a large pooled mean effect size of

d = 1.00, and later reviews with a more specific focus

(e.g., depression) have found similar effects (Johansson

and Andersson 2012). As guided iCBT is the treatment

format that is focused in this review we will not comment

further on the unguided treatments, while acknowledging

that there is a room and place for such programs (e.g., the

smoking cessation example), and that future automated

programs may be developed that show sufficient evidence

in terms of treatment effects and that may mimic the char-

acteristics of guided treatments (e.g., therapist support).

The Role of Guidance

Not much has been written on the way guidance in iCBT

should be provided (Titov 2010). Support is usually given

on a regular basis in the form of answers to questions,

encouragement, and feedback on homework assignments

(Paxling et al. 2013). It is important to note that a majority

of the correspondence tends to be in the form of encour-

agement (Sanchez-Ortiz et al. 2011). Usually, the support

consists of short text messages, like email, about once a

week, which means that the therapist spends about 15 min

per patient each week (for example in a 10 week treatment

program). When therapist behaviors were analyzed in a

study on generalized anxiety disorder (GAD), we found

that flexibility with homework completion was negatively

associated with the outcome, and that encouragement was

positively related to the outcome (Paxling et al. 2013).

Thus, in the cases were therapists granted the patient extra

time to work on assignments patients were less improved,

potentially indicating that a clear deadline is an important

part of iCBT (see below for more on this topic). There is a

version of iCBT that is conducted in real time, which is

more like a form of ‘‘chat’’. This form of treatment has

been evaluated in a few studies and is likely effective

(Kessler et al. 2009). However, real time online treatment

does not save time for the therapist, but may be a conve-

nient option for clients who cannot reach a clinic easily.

For these patients, video conferencing, where therapist and

patient communicate using web cameras, might be a suit-

able treatment alternative if the clients are less comfortable

with text interaction. In one form of iCBT treatment called

‘‘Interapy’’ there is a significant amount of writing

assignments for the client, which the therapist reads and

comments on in detail (Ruwaard et al. 2011). This version

of iCBT requires more therapist time, but is about as

effective as treatments with minimal therapist contact (e.g.,

10 min or less per week). In one study the difference

between email-based treatment based on an individual

analysis and guided standardized iCBT for depression was

investigated (Vernmark et al. 2010). The individualized

email treatment worked well, but it can be debated whether

the added effect justified the substantially increased ther-

apist time that was needed.

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Assessments

There are several key aspects of how guided iCBT can be

implemented in order to be effective. First, careful

assessments before treatment is important so that the per-

son can be matched to the correct treatment (Andersson

et al. 2009a). This assessment may include a diagnostic

evaluation and an assessment of the general requirements

in order to be able to take part of iCBT. One example of a

requirement could be that the person has the opportunity to

work with the treatment material at least a few hours a

week, and sometimes even every day, when engaging in

certain types of behavior change, such as behavioral acti-

vation for depression. Of note is that these requirements

generally do no differ from those that would be applied in

conventional face-to-face CBT.

An important part of Internet treatment is that self-report

inventories are completed online as well as the treatment.

Online data collection presents several advantages over

more traditional measurement methods with increased

more control, fewer data recording errors and more flexi-

bility. This is a research area in itself, where several studies

have demonstrated that psychometric properties are main-

tained when questionnaires are administered over the

Internet. For example, commonly used measures in

research on depression (Hollandare et al. 2010), panic-

(Carlbring et al. 2007a), and social anxiety disorders

(Hedman et al. 2010b) have been found to have adequate

psychometric properties when administered online. One

advantage of completing questionnaires on the Internet is

that items are not skipped (some clients can fail to report

the important issues or even accidentally miss to complete

a whole questionnaire page when they fill in ‘‘paper-and-

pencil’’ forms). Summary scores of the online question-

naires can also be calculated automatically and thus speed

up a screening process. Another important feature is that

iCBT is highly suitable for collecting symptom data on a

weekly basis throughout the treatment as the patient does

not have to log into a separate system, but is required to

complete assessments in order to access the treatment. At

the Internet Psychiatry Unit (IPSY) in Stockholm, Sweden,

the assessment system also has the advantage that it alerts

the therapist when a patient reports suicidal thoughts or

severe depressive symptoms. This is an important feature

of the clinical implementation of iCBT, as therapists tend

to treat several patients simultaneously. These patients may

not have started treatment at the same date, may not suffer

from the same diagnosis, and may be less ‘‘pure’’ in their

symptomatic presentation than participants in iCBT trials.

All these factors make it more difficult for the therapist to

keep track of their patients and automated alert systems are

therefore very valuable.

Data Security

Data security is important to consider when delivering

Internet-based treatments (Bennett et al. 2010). The sys-

tems that we work with are like the systems used when

paying bills online, that is, they are encrypted and use a

double authentication procedure at login. The latter is used

to reduce the probability of identity theft by not only

demanding a personal password to log in, but also a unique

single-use password that is sent automatically to the cli-

ent’s cell phone. All communication with the client is done

within a closed system and not the client’s personal email.

If email and SMS messages are used it is important that

they are designed so that they would not cause harm if

someone else would read the message without the patient’s

approval. An example of acceptable messages might be

simple reminders such as ‘‘You have a message in your

inbox’’. The systems used are continuously updated to meet

the latest security requirements. A possible danger is that

the more secure a system becomes, the more likely the

user-friendliness decreases. Hence, older people and indi-

viduals with only limited computer skills may have prob-

lems accessing very secure systems.

Treatment Contents

The contents of iCBT have gradually changed. When we

started with iCBT we used only PDF files that were

downloaded by the participants and then read. This was

necessary in the late 1990s, because few people had access

to high speed Internet connection by that time. Today, most

people using the Internet in Northern Europe have broad-

band access, and this allows for use of audio files, streamed

videos and interactive elements. However, the treatments

are still basically self-help texts that can either be down-

loaded or viewed directly on the screen. Interestingly, there

are no strong empirical reasons to believe that more

interactive programs would be better than mainly text-

based programs. One possible reason could be that some of

the more interactive programs have been fairly brief and

may therefore not convey the same amount of treatment as

in text-based iCBT. In the longer text-based treatments the

material has often been of book length, and with the

exception of the lesser input from the therapist, little has

been lost by going from face-to-face session to text (An-

dersson et al. 2009a). In fact, it may even be that the text

versions of the standard CBT treatments include more

information and components than is possible to present

during 1-h face-to-face sessions. The length of iCBT has

often been the same as in face-to-face CBT. For example, a

treatment for panic disorder may last for 10 weeks, which

is a fairly typical length of a face-to-face treatment for that

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condition. Moreover, it is important to note that iCBT

probably is not easier or less demanding for a client than

when seeing a therapist. The active treatment mechanisms

are most likely not different from traditional CBT. Thus,

for example, when exposure and response prevention is the

central part of CBT for obsessive–compulsive disorder

(OCD), these treatment components are retained in iCBT

(Andersson et al. 2011b), and it is mainly the administra-

tion format that differs (i.e., instructions in a session versus

instructions via text). Guided iCBT can be seen as a form

of distance learning online. The client receives texts to read

(and sometimes videos to view), and tasks to complete in

real life. When the homework assignment is sent in the

client gets feedback from the therapists. In the clinical

application (IPSY), there is also an automatic tracking

system that signals when the client has not been active for a

while. For these cases, the clinician may send a reminder or

even make a phone call.

In guided iCBT the text chapters (called treatment

modules) have associated online features such as quizzes

on the text. Most programs contain between 6 and 15

modules that often follow a determined structure. Treat-

ment always begins with educational elements (psycho-

education), and ends with relapse prevention/termination.

In between are modules that are based on treatment man-

uals for specific disorders like OCD, depression and other

psychiatric conditions. Modules are constantly revised and

new features may be added or removed. For example,

mindfulness exercises can be added, whereas sometimes

modules are either extended or shortened to fit better with

the client population at hand. From having been based on

established CBT protocols for conditions such as panic

disorder, we have also developed more unique treatments

that are not based on earlier manuals. In these cases, an

Internet treatment may be preceded by a clinical face-to-

face study. Research on severe health anxiety (previously

known as hypochondriasis) is an example, when we first

conducted an open pilot study of group treatment (Hedman

et al. 2010a), and later went on with a controlled iCBT

study (Hedman et al. 2011a). Modules used in the treat-

ment may vary in length, from short summaries to longer

texts of more than 20 pages of text. Illustrations are often

included as well as case vignettes. Writing good self-help

texts is a challenge and goes beyond presenting facts and

clear instructions in terms of exercises. In addition, the

texts should convey empathy and understanding for the

reader (Richardson et al. 2010). Self-help texts in iCBT

need to be easy to understand, while still providing clear

behavioral instructions and fit the entire range of problems

that can be experienced within a diagnosis. For example, a

person with social anxiety disorder may receive much

support from close relatives but at the same time such help

can have the function of a safety behavior, which prevents

effective exposure. Both scenarios may need to be inclu-

ded in the text, that is, when a significant other can be

helpful and when the help is rather a maintaining factor of

the anxiety. Text modules also need to fit all types of

clients, from highly educated people who are used to

reading and understanding texts to persons who may have

a harder time reading and understanding instructions. To

handle this and other differences between clients (in par-

ticular in terms of comorbidity between different prob-

lems), we have developed a form of iCBT that tailors the

intervention according to patient preferences and symptom

profile (Carlbring et al. 2010). This has been possible since

we have modules developed for several different problem

areas, including somatic problems. The tailoring means

that the client gets a treatment that is personalized. Some

may be able to handle more modules and others fewer. In a

depression trial, we developed briefer versions of some

modules for the clients with less capacity to read much text

(Johansson et al. 2012b). For a specific client tailoring may

include standard modules on psychoeducation and termi-

nation of treatment. However, in between there is room for

individualization, and if a client has problems with social

anxiety, insomnia and stress it is possible to combined

modules to fit in with that specific symptom profile.

Modules need to be rewritten to fit this approach and some

problem areas include a set of modules that go together.

However, all references to specific disorders are removed,

making tailored iCBT an example of a transdiagnostic

treatment, as comorbidity is allowed and accounted for. In

one study, we found that it also worked when the client

could choose a large part of the treatment content

(Andersson et al. 2011a), making room for client prefer-

ences. This approach, where a client actually could decide

to work with stress problems and not work with what

would have been prescribed if the diagnosis had been the

main indicator of the treatment content, worked well.

Thus, being given the option to choose modules following

a short description did not appear to have a negative effect

on outcome.

The Role of a Deadline

One aspect of iCBT treatment, as we have implemented it,

is that there is a clear deadline for treatment completion

(Andersson et al. 2009a). It may not seem obvious, but

compared to face-to-face treatments it can be less clear for

a client when the treatment ends. We have found that a

distinct deadline and an interview in association at the end

of therapy fosters adherence and also reduces dropout

(Nordin et al. 2010). This is does not mean that all clients

complete the full treatments, but it reduces the risk of

postponing the difficult, perhaps anxiety-provoking parts of

the treatment.

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In summary, iCBT is similar to bibliotherapy in that

text material is the primary treatment content. However,

the availability of support differs markedly from biblio-

therapy as it can be provided offline asynchronous, but

also rapidly outside of office hours. It is even the case that

iCBT provides greater opportunities for rapid feedback

than usual CBT provides. A client in iCBT can quickly

get feedback on homework and also get answers to

questions (which in face-to-face therapy can occur during

the next session if it is not very urgent). The client can go

back to read and repeat instructions which probably

facilitates learning (Andersson et al. 2012a). Indeed, it is

not clear how much a client remembers from a face-to-

face session, which can be problematic. In iCBT this is

probably less of a problem. In addition, in some cases, as

with social anxiety disorder, an advantage with iCBT is

when the psychologist is a source of anxiety in face-to-

face CBT, which could inhibit learning. Having described

the content and structure of iCBT we now turn to sum-

marizing the research support in the field of mild to

moderate psychiatric conditions.

Efficacy Studies

iCBT has been the subject of much research, and in the last

14 years a significant amount of randomized controlled

studies have been conducted for a range of clinical con-

ditions (Hedman et al. 2012b). Only in the areas of

depression, social anxiety-, and panic disorders, at least 40

randomized controlled trials have been conducted. In this

review, we will cover the support for guided iCBT for a

selection of psychiatric conditions, for which there is

empirical evidence in the form of randomized controlled

trials. In this section, we will cover efficacy studies, that is,

studies with research participants recruited via advertise-

ment from the general public. We focus on major depres-

sion, panic-, social anxiety disorder and GAD, but we also

mention research on clinical applications with somewhat

less evidence, such as the treatment of specific phobia,

OCD, severe health anxiety, and mixed anxiety. For each

condition, we ask three questions: (a) How good is the

treatment compared with untreated controls? (b) Do the

effects last? and (c) Is iCBT equally effective as traditional

face-to-face CBT?

Depression

There have been at least 20 controlled studies on iCBT for

mild to moderate depression (Johansson and Andersson

2012), although many have not been in the form of guided

iCBT. In the first study from Sweden, iCBT was com-

pared with a condition where clients participated in a

moderated online discussion group (Andersson et al.

2005). A total of 117 people participated in the study, and

the treatment lasted for 10 weeks. A between group effect

size of d = 0.88 was found at posttreatment. However,

there was relatively large dropout from the study (27 %),

which was addressed in later studies by being clear about

a deadline for completing the following survey. In a

subsequent study we compared guided self-help with

email-based therapy and a waiting list (Vernmark et al.

2010). In this study a total of 88 participants were

included. There was significant between group effect

between iCBT and control (d = 0.96 for email therapy

and d = 0.56 for guided self-help). Dropout from the

study was low (3 %). There was no significant difference

between the two active treatments, although the email

therapy appeared to be somewhat better. It should be

mentioned that the guidance provided was minimal for the

guided self-help group. Participants in the study were

followed up 3.5 years after treatment and depression

levels remained low for those who responded to the fol-

low-up, which was 58 % (Andersson et al. 2013a). The

third study from Sweden answered the question about the

difference between iCBT and face-to-face group CBT

(Andersson et al. 2013b). The study included 69 depres-

sed subjects who were randomized to either guided iCBT,

with the same program as mentioned above, or to a group

therapy condition. The study also included a 3-year fol-

low-up. The results showed that both treatments resulted

in significant effects with a within-group effect of d = 1.46

for the iCBT condition and d = 0.99 for group treatment

(pre- to posttreatment). The between group effect was in

favor of iCBT at posttreatment d = 0.58, and at 3-year

follow-up d = 0.55. Another trial has been published from

our group using a program that was based on acceptance-

oriented CBT and behavioral activation (Carlbring et al.

2013). This study showed a large between group effect

when the treatment was compared against a waiting list

control group. In a trial aimed at investigating if iCBT can

be effective in preventing relapse in depression, it was

found that persons who had residual symptoms of depres-

sion and had previously been treated for at least one

depression episode, could benefit from guided iCBT as a

form of relapse prevention (Hollandare et al. 2011). Sig-

nificantly fewer in the iCBT group relapsed a 6 months

follow-up (10.5 %), compared with a control group who

did not receive treatment where 37.8 % relapsed into

depression. The promising effects of guided iCBT for

depression has been replicated in other countries. Con-

trolled trials have been conducted in for example Australia

(Perini et al. 2009; Titov et al. 2010), The Netherlands

(Ruwaard et al. 2009), and Switzerland (Berger et al.

2011b). In sum, guided iCBT has been found to work in

controlled trials, a few studies show that effects last over

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time and there are indications that guided iCBT can be as

effective as group CBT.

Panic Disorder

In the case of panic disorder, there are slightly fewer

studies than on depression. The first controlled trial was

completed and published more than 10 years ago (Carl-

bring et al. 2001). In that study iCBT was compared to a

waiting list condition (Carlbring et al. 2001), with a total of

41 individuals. Between group effects were strong for the

panic-related measures (e.g., d = 1.10). In another study,

the panic program was tested against applied relaxation

delivered via the Internet (Carlbring et al. 2003). This was

a small study (N = 22), and the feedback from the therapist

was minimal and had a rather long delay. Results showed

that both treatments yielded medium to large within-group

effects (Cohen’s d = 0.71 for applied relaxation and

d = 0.42 for iCBT), and that there was no statistically

significant difference between the two treatments. A third

iCBT study on panic disorder was a direct comparison

between guided iCBT and manualized face-to-face CBT

(Carlbring et al. 2005). This study included 49 participants.

Results showed large within-group effects (Cohen’s

d = 0.80 for the iCBT group and d = 0.93 for the face-to-

face treatment group), and there were no significant dif-

ferences between the two treatments. In a subsequent

fourth panic study from Sweden, we wanted to increase

adherence to the treatment protocol and introduced weekly

brief phone calls (Carlbring et al. 2006). A total of 60

participants were randomized to guided iCBT or to a

waiting list control condition. In line with the previous

studies between group effects were large, with an average

between group effect size of d = 1.0 (Carlbring et al.

2006). Other research groups have found very similar

results. Two separate groups in Australia have conducted

controlled trials and have found that guided iCBT leads to

improvements in clients with panic disorder (Klein and

Richards 2001; Klein et al. 2006; Wims et al. 2010). There

is also at least one direct comparative trial suggesting

equivalence between guided iCBT and face-to-face CBT

for panic disorder (Kiropoulos et al. 2008), and one addi-

tional Swedish effectiveness trial showing similar findings

(Bergstrom et al. 2010). In addition, there is a study from

The Netherlands on panic symptoms (Ruwaard et al. 2010).

With the exception of the Dutch study (Ruwaard et al.

2010) which reported 3 year follow-up data, the typical

panic trial has only provided 1-year follow-up data (Carl-

bring et al. 2005). Overall, there is established support in

efficacy studies that guided iCBT works for panic disorder

with or without agoraphobia. Moreover, the results appear

to be similar to face-to-face CBT. As with most studies on

iCBT it has mainly been adults who have been included in

the trials.

Social Anxiety Disorder

Social anxiety disorder (formerly called social phobia) has

been the subject of several studies since the first Swedish

study (Andersson et al. 2006), and also many studies from

other countries. In the first trial, a total of 64 persons with

social anxiety disorder were included out of which 70 %

had generalized social anxiety disorder. Participants were

randomized to guided iCBT or to a waiting list condition.

The treatment lasted for 9 weeks. Between group effects at

posttreatment showed a moderate effect size d = 0.70, and

results were sustained at 1-year follow-up. In should be

mentioned that the study included two face-to-face group

exposure sessions, but in the subsequent study which

included 57 participants there was no face-to-face meet-

ings, but instead brief telephone calls. Comparing against a

waiting list control condition the between group effect was

large, d = 0.95 (Carlbring et al. 2007b). A 1-year follow-

up showed that the results were maintained. Since then,

these findings have been replicated in several studies, some

of which have been large with over 200 participants

(Furmark et al. 2009). The most recent effectiveness study

from our group was a large controlled study (N = 204),

where guided iCBT was compared against participation in

an online discussion group (Andersson et al. 2012a). The

results were in line with previous studies with a large

between group effect (Hedges g = 0.75). A special feature

of the study was that knowledge about social anxiety was

measured before and after treatment. Results showed that

knowledge increased and that participants were more

confident in their knowledge after treatment. Another

aspect of the study was that experienced Internet therapists

were compared with those who had no prior experience of

guiding iCBT. There was no difference in effect between

the two categories of therapists, even if the experienced

therapists spent less time guiding their clients. When it

comes to the question of equivalence between guided iCBT

and face-to-face CBT there are not many studies but one

fairly large study compared guided iCBT against group

CBT (Hedman et al. 2011c). The trial included 126

participants and large significant within-group effects were

found for both treatments (d = 1.42 for iCBT and

d = 0.97 for group CBT). There was even a tendency for

iCBT to be more effective, with a between group effect of

d = 0.41 in favor of the iCBT condition. In addition to

1-year follow-up data, which often are included in the

primary trials, there are two long-term follow-ups. One

collected data 30 months after treatment completion

(Carlbring et al. 2009), and the second 5 years after the end

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of treatment (Hedman et al. 2011d). Both studies showed

that the treatment effects were sustained. Research on

guided iCBT for social anxiety disorder has been con-

ducted at several places in the world and especially in

Australia, where numerous studies have been conducted

which have shown that iCBT can yield large improvements

(Titov et al. 2008), including showing that iCBT is as

effective as usual CBT (Andrews et al. 2011). Studies from

Switzerland (Berger et al. 2009, 2011a) and Spain (Botella

et al. 2010) support the notion that treatment of social

anxiety disorder via the Internet works. In sum, there is

substantial evidence from independent research groups that

iCBT leads to reduced symptoms of social anxiety disor-

der. Guided iCBT can be at least as good as conventional

CBT and effects appear to be sustained over time.

Generalized Anxiety Disorder

There are only a few studies of guided iCBT for GAD. The

first Swedish controlled study included a 3-year follow-up

when it was published (Paxling et al. 2011). The study

included 89 participants and the results after treatment

showed strong between-group effects (d = 1.11 compared

with a waiting list). The results at follow-up 1- and 3 years

after treatment showed that anxiety levels were further

reduced. The next study we conducted on GAD compared a

psychodynamically oriented guided self-help via the

Internet against iCBT and a waiting list control group (total

N = 81) (Andersson et al. 2012c). While there were sig-

nificant within-group effects (d [ 1.0) for both active

treatments, the waiting list group also improved which

resulted in small between group effects. There was no

difference between the active treatments. An 18-month

follow-up was conducted which showed that results were

sustained. This trial was the first to test psychodynamically

oriented Internet treatment and has been followed by a trial

on psychodynamic Internet treatment for depression

(Johansson et al. 2012a). In addition to these studies there

is just one group that have performed controlled studies on

iCBT for GAD (Robinson et al. 2010; Titov et al. 2009). In

these Australian studies, the effects were similar to those

we found in the Swedish studies. To our knowledge there is

no published comparison of iCBT versus face-to-face CBT

for GAD. In summary, there are as yet few studies on iCBT

for GAD, even if the results are promising in terms of

efficacy and long-term follow-up results.

Other Anxiety Disorders and Mixed Conditions

Guided iCBT has been tested for other anxiety disorders.

For example, there are trials on posttraumatic stress dis-

order and symptoms showing the guided iCBT works

(Lange et al. 2003; Spence et al. 2011b). For severe health

anxiety (previously called hypochondrias) there is one

controlled study (Hedman et al. 2011a). The study included

81 participants and the treatment, which had a strong focus

on exposure and response prevention, was compared with

an attention control condition (web-based discussion for-

ums). The between group effect on the main outcome

measure was d = 1.62, and results were maintained at

follow-up 1 year after the end of treatment (Hedman et al.

2013). OCD is a relatively new field for iCBT, at least if we

look at the number of published articles. There is at least

one controlled study (Andersson et al. 2012b), which

included 101 people with OCD. The between group effect

against waiting list control was d = 1.12. Little has been

done on specific phobia when it comes to guided iCBT,

with only one small study on spider phobia (Andersson

et al. 2009c).

There are also new studies on mixed conditions, moti-

vated by the fact that comorbidity is the rule rather than the

exception in anxiety and mood disorders. As mentioned we

have developed a form of iCBT that tailors the intervention

according to patient preferences and symptom profile. This

has the advantage that the treatment does not have to rely

as much on distinct diagnostic categories. For anxiety

comorbid with other psychiatric problems, there are two

controlled studies (Carlbring et al. 2010; Silfvernagel et al.

2012). The results from the first controlled study (N = 54)

showed that tailored treatment works with a between group

effect at the end of treatment of d = 0.69 when compared

to controls (Carlbring et al. 2010). The effects were sus-

tained at 1- and 2 years after treatment. Tailored guided

iCBT has also been tested for panic symptoms (Silfver-

nagel et al. 2012). In a depression trial tailored treatment

was directly compared against standard iCBT and a control

group (Johansson et al. 2012b). In that study (N = 121)

we found that tailored treatment was significantly better

than the standard treatment for those clients who had more

severe depressive symptoms. In addition to the Swedish

tailored treatment there is another related approach to

iCBT, developed and tested in Australia, where a ‘‘trans-

diagnostic’’ approach (with the option of additional mate-

rial) has been found to be effective (Titov et al. 2011).

In that study, which included 77 participants between-

groups effect sizes were moderate, ranging between 0.52

and 0.58.

In sum there are conditions for which only few con-

trolled trials on guided iCBT exists. Overall, there is to date

little research on severe health anxiety, OCD and specific

phobia. The preliminary results are promising, however,

but independent replications are needed. Two promising

approaches have been developed to handle the problem of

comorbidity and exclusion from trials that focus on specific

conditions. Both tailored guided iCBT and transdiagnostic

iCBT appears to be promising new treatments.

J Contemp Psychother (2013) 43:223–233 229

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Effectiveness Studies

As seen in this review, the literature is dominated by

efficacy studies, but there are published effectiveness

studies showing that guided iCBT appears to work in more

regular clinical settings. It should be noted that the dis-

tinction between efficacy and effectiveness is not obvious

in iCBT studies, where participants are recruited from the

general public (Andersson et al. 2009b). There are however

studies from Sweden which have been conducted in a

regular clinical setting (Bergstrom et al. 2009, 2010;

Hedman et al. 2011c), and there are also effectiveness data

from clinics in Australia (Aydos et al. 2009), and The

Netherlands (Ruwaard et al. 2012). There are also studies

examining guided iCBT in primary care (Shandley et al.

2008). All of these studies support the notion that iCBT

works in more regular clinical settings. At the IPSY in

Stockholm guided iCBT has been provided as a standard

treatment since 2007. As the treatment includes outcome

monitoring there are now data from many clients with

specific conditions. In a recent report of this database, all

562 patients who had received treatment for their panic

disorders were included (Hedman et al. 2013). The results

showed within-group effects of d = 1.07–1.55. In a study

from Australia, effectiveness data were reported from 359

patients who had been prescribed the Sadness program for

depression (Williams and Andrews 2013). Results showed

medium to large within-group effect sizes d = 0.51–1.13.

In another report from the same research group similar

effects were found for the treatment of GAD (Mewton et al.

2012) in a clinical sample of 588 patients, with a within-

group effect size of d = 0.91 (based on data from 324

patients). A preliminary conclusion is that guided iCBT

works in everyday clinical settings for major depression,

social anxiety disorder, GAD, and panic disorder, but more

reports are needed and it needs to be said that it has mainly

been in specialist units and not in general practices or

clinics without previous experience of iCBT.

Discussion

Guided iCBT has quickly been established in research and

is gradually but slowly implemented in some countries,

mainly Sweden and Australia. Several challenges exist for

the future. First, it is clear that iCBT primarily has been

developed and tested for mild to moderate mental health

problems. For more severe problems, like bipolar disorder

and schizophrenia, very little has been done. For these

conditions, iCBT is more likely to be into form of a

complement. Another second aspect that has been tested in

Germany is to use the Internet for aftercare (Golkaramnay

et al. 2007), which could be useful as a booster treatment

after conventional CBT for conditions like OCD. Thirdly,

technology is developing rapidly, and today the Internet is

accessed not only via computers, but increasingly through

modern mobile phones. A challenge for the future is thus

the new technology with smartphones. New technologies

may open up new possibilities for the delivery of CBT and

research has begun in this field (Watts et al. 2013). A fourth

challenge for the future purpose is to transfer iCBT pro-

tocols into different languages. For example, since the

treatments often are text based it is fairly easy to translate

and adapt a treatment to another culture (Choi et al. 2012).

This could be a way to disseminate CBT to countries where

there are few trained CBT therapists or limited resources.

In addition to these challenges, there are yet few treatments

that are designed for children, adolescents and the elderly,

although studies are beginning to emerge (Spence et al.

2011a). In the present paper we did not review the cost-

effectiveness studies on iCBT. There is however an

increasing body of knowledge indicating that iCBT could

be a highly cost-effective treatment (Hedman et al. 2011b).

Finally, in this paper we did not focus on moderators and

mediators of treatment outcomes in relation to iCBT. There

is a growing literature on the role of the therapeutic alli-

ance in iCBT (Andersson et al. 2012d), patient predictors

(Andersson et al. 2008), the role of genetics (Hedman et al.

2012a), the need for a trained therapist versus a lay person

providing the guidance (Titov et al. 2010), and therapist

factors in general (Almlov et al. 2011). Studies on treat-

ment mechanisms will appear as iCBT may facilitate out-

come monitoring and mediator assessment on a weekly

basis, which is needed for robust mediator studies.

Conclusions

Based on the available evidence, partly reviewed in this

paper, the following conclusions can be drawn. Guided

iCBT has good research support for the treatment of

depression, social anxiety-, and panic disorders. For those

conditions guided iCBT could be an alternative to tradi-

tional CBT. There are also studies on GAD, severe health

anxiety, mixed anxiety, OCD and other anxiety disorders

which all point in the same direction. In the few studies that

directly have compared guided iCBT against conventional

face-to-face CBT there has usually been no differences in

effect. Studies conducted in more representative clinical

settings are few but indicate that guided iCBT works when

delivered as a regular treatment for typical psychiatric

patients. Given the potential benefits of increasing access to

evidence-based psychological treatment and the health

economic benefits of iCBT, this new treatment format

should be considered as a complement to conventional

CBT for mild to moderate mental health problems.

230 J Contemp Psychother (2013) 43:223–233

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