www.elsevier.com/locate/schres

Schizophrenia Research

Neurocognitive and symptom correlates of daily problem-solving

skills in schizophrenia

Nadine Revheim a,*, Isaac Schechter a, Dongsoo Kim a, Gail Silipo a,

Baerbel Allingham c, Pamela Butler a,b, Daniel C. Javitt a,b

a Program in Cognitive Neuroscience and Schizophrenia, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road,

Orangeburg, NY 10962, USAb Department of Psychiatry, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA

c Information Science Division, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA

Received 10 June 2005; received in revised form 2 December 2005; accepted 17 December 2005

Available online 27 January 2006

Abstract

Functional outcome for individuals with schizophrenia has been associated with cognitive impairment. Deficits in attention,

memory, speed of information processing and problem-solving skills affect independent functioning, vocational performance,

and interpersonal functioning. This study investigated the relationship between neurocognitive functioning, clinical symptoms

and daily problem-solving skills in seriously and persistently ill persons. Thirty-eight inpatients and outpatients were

administered a neurocognitive battery for attention, working memory, processing speed, perceptual organization, and executive

functioning; and semi-structured clinical interviews using the BPRS and SANS. Estimates of daily problem-solving skills were

obtained using the relevant factor subscale from the Independent Living Scales (ILS-PB). Daily problem-solving skills were

significantly correlated with negative symptoms, processing speed, verbal memory, and working memory scores. A regression

model using an enter method suggests that working memory and negative symptoms are significant predictors of daily problem-

solving skills and account for 73.2% of the variance. Further analyses demonstrate that daily problem-solving skills and

negative symptoms were significantly different for inpatients and outpatients and significantly correlated with community

status. The findings suggest the ILS-PB has utility as a proxy measure for assessing real-world functioning in schizophrenia.

D 2006 Elsevier B.V. All rights reserved.

Keywords: Schizophrenia; Neurocognitive functioning; Negative symptoms; Community functioning; Daily problem-solving skills;

Independent living scales

0920-9964/$ - see front matter D 2006 Elsevier B.V. All rights reserved.

doi:10.1016/j.schres.2005.12.849

* Corresponding author. Tel.: +1 845 398 6543; fax: +1 845 398

6545.

E-mail address: revheim@nki.rfmh.org (N. Revheim).

1. Introduction

Researchers have focused on the relationships

between neurocognitive deficits and functional out-

come (Evans et al., 2003; Dickinson and Coursey,

83 (2006) 237–245

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245238

2002; Green, 1996; Green et al., 2000; Twamley et al.,

2002); neurocognitive deficits and clinical symptom-

atology (Berman et al., 1997; Harvey et al., 1997;

O’Leary et al., 2000; Suslow et al., 1998); and the

interrelationships of neurocognition, positive and

negative symptoms, and aspects of functioning in

daily life (McGurk et al., 2000; Tamminga et al.,

1998; Velligan et al., 1997). This quest for the relative

contribution of cognitive impairment and symptoms

to adaptive functioning for individuals with schizo-

phrenia has led to the understanding that both

cognitive impairment and negative symptoms are

independent, but together are largely responsible for

deficient performance in activities of daily living from

basic self care to social interaction, instrumental life

skills and community outcome. An emerging research

consensus suggests the importance of specific cogni-

tive impairment in processing speed, working mem-

ory, executive functioning and verbal memory

(Dickinson and Coursey, 2002; Gold et al., 2002;

Green, 1996; Green et al., 2000).

Most studies have been directed towards particular

populations (e.g. long-term; geriatric; community-

dwelling) and have used diverse measures to assess

levels of adaptation that are either global impressions

with descriptive anchors (Dickinson and Coursey,

2002) or performance-based instruments that rely on

role-playing (Twamley et al., 2002). The lack of

uniform measures for functional outcome for all

settings and paucity of empirical data about the

relative utility of the functional measures compared

to the standardized evaluations available for clinical

ratings and neurocognitive assessment is noteworthy.

We have previously evaluated the psychometric

properties of one potential functional outcome scale

that may fill this gap, the Independent Living Scales

(ILS, Loeb, 1996) problem-solving factor (ILS-PB),

for use with individuals with schizophrenia. The

present study evaluates the symptomatic and neuro-

psychological correlates of ILS-PB performance in a

mixed group of psychiatric inpatients and outpatients

to further establish its discriminant validity with this

clinical population.

The ILS was initially developed as a scale

evaluating capacity for independent living in elderly

patients with cognitive disabilities, such as Alzheim-

er’s disease. Early studies demonstrated the ILS-PB

was significantly associated with the ILS total score

and was found to have the ability to predict

community status (Loeb, 1996). The ILS-PB has an

alpha coefficient of 0.86 and test–retest reliability of

0.90. Inter-rater reliability is 0.98. As reported in the

test manual, concurrent validity, as well as construct

and discriminant validity are adequate and suggest the

instrument is effective for evaluating levels of

independent community functioning in psychiatric

patients.

In prior studies in schizophrenia, the ILS-PB

showed significant capacity to distinguish patients

who are in different levels of care. In one study the

ILS-PB was shown to be more significant than verbal

memory in predicting inpatient vs. outpatient status

(Revheim and Medalia, 2004a). An additional study

found the ILS-PB to have better discrimination for

outpatient residential status than GAF ratings

(Revheim and Medalia, 2004b). Both studies estab-

lished the potential to use the ILS-PB to link cognition

and functional outcome but further study was pro-

posed to include additional measures.

A particular advantage of the ILS-PB is that it

takes only 20–25 min to administer and patients find it

largely non-aversive. Examples of questions are

bWhat might you do if your lights and TV went off

at the same time?Q and bTell me two ways you would

know it’s safe to cross a busy streetQ. Items are rated

on a 0 to 2 point scale according to the scoring

manual. These user-friendly capabilities suggest that

ILS-PB may be an addition to the armamentarium of

both clinicians and researchers working with seriously

and persistently mentally ill individuals as previously

advocated (see Revheim and Medalia, 2004b for

further discussion).

Despite the apparent clinical utility of ILS-PB, the

symptomatic and neuropsychological correlates of

problem-solving disability have not been fully eval-

uated in seriously mentally ill individuals. This study

investigated the validity of the ILS-PB, as a measure

of everyday problem solving, for defining functional

differences across diverse patient groups. In addition,

the present study evaluates ILS-PB performance

relative to structured clinical interview scales includ-

ing the Brief Psychiatric Rating Scale (BPRS),

Schedule for Assessment of Negative Symptoms

(SANS) and neuropsychological measures sensitive

to executive functioning, working memory and

sensory processing deficits.

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245 239

2. Methods

2.1. Participants

Thirty-eight participants (n =28 [74%] male, n =10

[26%] female) ranged in age from 19 to 55

(mean=39.2); with DSM-IV diagnoses of schizophre-

nia (n =29, 76%) and schizoaffective disorder (n =9,

24%); and long-term illness (mean illness dura-

tion=19 years; mean age, first hospitalization=20).

Participants were of varied ethnicity: 34% white

(n =13), 53% black (n =20), 13% Hispanic/Asian/

Other (n =5). Highest educational attainment for the

sample was 11.5 years. Current IQ estimate using the

Quick Test (Ammons and Ammons, 1962) was 96.4.

Individuals were recruited from an inpatient research

unit (n =24, 63%) and a variety of transitional and

residential community settings (n =14, 37%). All

participants were stabilized on medications with a

mean chlorpromazine dose of 1151 mg (S.D.=

515.2 mg.). Seventy-one percent of the participants

were on atypical neuroleptics, 21% were on a

combination of atypical and typical neuroleptics and

8% were on typical neuroleptics.

There were no significant differences between

inpatients and outpatients on demographic variables

(see Table 1). However, inpatients and outpatients

were distinctly different in terms of number of

hospitalizations and days in hospital for the 3 years

prior to testing: inpatients had a mean of 1.6

hospitalizations compared to 0.4 hospitalizations for

outpatients (t=3.7, p =0.001) and inpatients had an

average of 260.5 days of hospitalization compared to

89.8 for outpatients (t=2.1, p =0.04). At the time of

Table 1

Demographic characteristics of sample

Inpatients

Sample size 24 (63%)

Gender

Female 6 (25%)

Male 18 (75%)

Age (MFS.D.) 38.5F10.2

Age, 1st hospitalization (MFS.D., n =36) 19.4F6.5

Illness duration (MFS.D., n =35) 18.1F8.6

Symptom severity (BPRS, MFS.D.) 34.0F8.5

CPZE (MFS.D.) 1206.8F536

Education (MFS.D.) 10.9F2.3

IQ estimate (MFS.D., n =36) 93.3F11.3

testing, inpatients had been hospitalized for an

average of 344 days.

2.2. Procedures

All patients signed informed consent as part of

their enrollment in an ongoing study. Participants’

diagnoses were established using SCID interviews

administered by certified members of the research

team who received supervision and standardized

training with the DSM-IV modules. Patients were

excluded from study procedures if they had a history

of neurological impairment, mental retardation, cur-

rent alcohol or drug abuse within the previous month

or substance dependence within the past 6 months.

2.3. Measures

A comprehensive neurocognitive battery com-

prised of routine procedures to evaluate fine motor

(Grooved Pegboard), sensory processing (Tone

Matching Test), visual memory (Brief Visual Memory

Test, BVMT), semantic fluency (Categorical Verbal

Fluency-animals/fruits/vegetables), attention (Contin-

uous Performance Test-Identical Pairs, CPT-IP), ex-

ecutive functioning (WCST), verbal memory (WMS-

III Logical Memory), visual perception (WAIS-III

Perceptual Organization Index, POI: Block Design,

Picture Arrangement, Picture Completion, Matrix

Reasoning subtests; Wechsler, 1997a), processing

speed (WAIS-III Processing Speed Index, PSI: Sym-

bol Search and Digit Symbol-Coding subtests), and

working memory (WMS-III Working Memory Index,

WMI: Letter Number Sequencing, Spatial Span

Outpatients Total sample

14 (37%) 38 (100%)

4 (29%) 10 (26%)

10 (71%) 28 (74%)

40.4F9.8 39.2F9.9

20.8F2.9 19.9F5.4

19.4F8.8 18.6F8.6

35.8F9.3 34.7F8.7

.4 1056.0F480.4 1151.2F515.2

12.4F2.4 11.5F2.4

101.1F9.0 96.4F11.0

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245240

subtests; Wechsler, 1997b) was administered to each

participant.

Neurocognitive measures were operationalized

using selected scores for the various dependent

measures. For Grooved Pegboard, the sum of pins

placed with the dominant hand on trials 1 and 2 was

used. For Tone Matching Test, the minimum threshold

value to discriminate two tones was used. For the

BVMT, the raw score for the sum of all trials 1–3 was

used. For Categorical Verbal Fluency, the sum of all

items across all trials was used. For CPT-IP, the

percentage of total hits across 2, 3 and 4 digits was

used. For WCST, two scores were used: the number of

categories achieved and the number of perseverative

errors. For Logical Memory, the scaled score for total

immediate recall for two stories was used. For the

POI, PSI, and WMI, the scaled scores were used.

General psychopathology and positive symptoms

were assessed using the Brief Psychiatric Rating Scale

(BPRS) (Overall and Gorham, 1962). Negative

symptoms were assessed using the Schedule of

Negative Symptoms Scale (SANS) (Andreasen,

1981). BRPS and SANS ratings were acquired by

clinicians who were trained using standardized pro-

cedures with videotapes and consensus ratings that

met pre-established inter-rater reliability criteria rela-

tive to bgold standardQ ratings (F1 point).

The problem-solving factor subscale of the ILS,

consisting of 33 items related to money, home

management, health and safety issues and social

adjustment, was administered to measure reasoning

for daily problem-solving skills. Standardized scores

range from 20 to 60: 20–39 suggests the need for full

supervision for daily living (i.e., inpatient hospitali-

zation or nursing home setting); 40–49 suggests

moderate supervision is required for daily living

(i.e., structured community residence, adult home);

and 50 and above suggests the ability to function

independently in the community.

2.4. Data analyses

Data were examined for normal distributions using

plots and information about skewness. Four of the

twenty variables did not conform to the assumption of

normality (BPRS Positive Symptoms Factor, Tone

Matching Test, WAIS-III POI and WAIS-III PSI);

therefore nonparametric statistics were used accord-

ingly. Data were analyzed using Pearson Product

Moment and Spearman Rho correlations and multiple

regression in order to determine the relationships

among the variables. Variables that were entered into

the regression equation that did not have a normal

distribution were computed using a log transformation

for normalization of the data set. ANOVA and Mann–

Whitney U-tests were used to determine between

group differences related to community status (inpa-

tient vs. outpatients) for clinical symptoms, neuro-

cognitive measures and ILS-PB.

3. Results

3.1. Relationship between clinical symptoms and ILS-PB

Clinical symptoms that were significantly correlated with

the ILS-PB, after Bonferroni corrections, include the BPRS

withdrawal-retardation factor, SANS total score, and SANS

Affective Flattening and Alogia Global items (see Table 2).

Correlations with SANS remained significant whether or not

globals were included. When SANS sub-factors were

considered separately, significant correlations were observed

with Affective Flattening, Alogia, and Avolition, but not

with Asociality-Anhedonia global scores after Bonferroni

correction.

3.2. Relationship between neurocognitive measures and

ILS-PB

Neurocognitive measures that were significantly corre-

lated with the ILS-PB, after Bonferroni corrections, include

Tone Matching Test, CPT-IP, WMS-III Logical Memory,

WAIS-III Processing Speed Index (PSI) and WMS-III

Working Memory Index (WMI) (see Table 3). Other

neurocognitive measures including Grooved Pegboard,

Brief Visual Memory Test, Categorical Verbal Fluency,

WAIS-III Perceptual Organization Index (POI), and WCST

were not significant after Bonferroni correction. Fewer

participants completed the Categorical Verbal Fluency test

and Grooved Pegboard (n =11, respectively) than other tests

due to a minor adjustment in the overall battery during data

collection.

3.3. Multiple regression for ILS-PB

In order to determine which variables were most related

to daily problem-solving skills, the ILS-PB scores were

regressed on the five significant neurocognitive and clinical

symptoms variables after Bonferroni correction to p b0.005

Table 2

Relationship of ILS-PB with clinical symptomsa

Mean S.D. Correlation coefficient ( p value)b

ILS-PB (scaled score) 35.0 11.5 –

BPRS total score 34.7 8.7 �0.29 (0.08)

BPRS withdrawal-retardation factor 6.8 3.0 �0.49 (0.002)

BPRS positive symptoms factorc 8.5 4.4 �0.11 (0.5)

SANS total, with global scores 34.5 15.2 �0.58 (b0.001)

SANS affective flattening global item 1.6 1.2 �0.52 (0.001)

SANS Alogia global item 1.3 1.1 �0.45 (0.005)

SANS Avolition global item 2.3 1.1 �0.39 (0.016)

SANS Asociality-Anhedonia global item 2.2 0.86 �0.33 (0.04)

a n =38, Pearson Product Moment Correlation, unless otherwise noted.b Bonferroni correction for 0.05 level for 2 measures is 0.025.c Spearman Rho correlation.

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245 241

for 10 comparisons. They were the BPRS withdrawal-

retardation factor, SANS total score with globals (SANS-

TG), WMS-III Logical Memory, WAIS-III Processing

Speed Index (PSI) and WMS-III Working Memory Index

(WMI). WAIS-III PSI required a log transformation for

normalization of data for this analysis. Regression was

performed using an enter method for multiple regression. In

order to avoid redundancy, SANS was entered only once, as

total score with globals.

The model explained 73.2% of the variance in the ILS-

PB scores ( F[5,30] =13.7, p b0.001) when all the

variables were taken into account. The two significant

predictor variables in the model were SANS-TG

(t =�3.38, p =0.002) and WMS-III WMI (t =3.33,

Table 3

Relationships of ILS-PB and neurocognitive measuresa

M

Grooved Pegboard (sum, dominant hand, trials 1, 2)c 2

Tone Matching Test (percent threshold difference)d 2

Brief Visual Memory Test (raw score, sum, trials 1–3) 1

Categorical Verbal Fluency (sum, all trials)c 3

CPT-IP (percentage of total hits across 2, 3, 4 digits)e

WCST-Categories (number of categories achieved)

WCST-Perseverations (number of perseverative errors) 1

WMS Logical Memory, Recall Total Score (scaled score)f

WAIS-III Perceptual Organization Index (POI, scaled score)d 8

WAIS-III Processing Speed Index (PSI, scaled score)d 7

WMS-III Working Memory Index (WMI, scaled score) 6

a n =38, Pearson Product Moment correlations, unless otherwise noted.b Significance level adjusted to 0.01 for multiple, related cognitive testsc n =11.d Spearman Rho correlation.e n =29.f n =31.

p =0.003). WMI and SANS-TG showed limited intercor-

relation (r =�0.08, p =0.62), suggesting relative indepen-

dence of contributions.

3.4. Community status differences in neurocognitive, clinical

and daily problem-solving skills

In order to determine what variables were different

according to community status (inpatients vs. outpatients),

ANOVA and Mann–Whitney U-tests were performed across

all clinical and neurocognitive variables, including ILS-PB.

Bivariate correlations of all measures were also obtained to

further illustrate the relationship of each variable with

community status (see Table 4).

ean S.D. Correlation coefficient ( p value)b

3.5 8.0 0.65 (0.03)

7.2 28.5 �0.44 (0.006)

3.0 7.9 0.13 (0.45)

1.0 8.6 0.69 (0.02)

0.47 0.28 0.50 (0.007)

1.7 1.5 0.28 (0.09)

2.4 6.5 �0.36 (0.03)

4.4 2.5 0.56 (0.001)

0.5 13.5 0.35 (0.03)

7.9 12.3 0.65 (b0.001)

7.5 12.7 0.60 (b0.001)

.

Table 4

Community status differences in neurocognitive, clinical and daily problem-solving skills

Inpatients Outpatients Test statistica,b p rc,d

Mean S.D. Mean S.D.

ILS-PB** 31.4 9.2 41.6 12.1 8.7a 0.006 0.44c

BPRS Total 34.0 8.5 35.8 9.3 0.3a 0.559 0.10c

SANS Total with Globals** 39.8 12.8 25.5 15.2 9.6a 0.004 �0.46cGrooved Pegboard 23.3 8.8 24.5 4.9 0.1a 0.863 0.06c

Brief Visual Memory Test 14.3 7.1 10.8 9.1 1.7a 0.202 �0.21cCategorical Verbal Fluency 30.9 8.1 31.5 14.8 0.1a 0.933 0.03c

CPT-IP .42 .29 .54 .27 1.1a 0.307 0.20c

WCST-categories achieved 1.4 1.4 2.3 1.4 4.2a 0.047 0.32c

WCST-perseverative errors 13.7 6.9 10.2 5.4 2.6a 0.116 �0.26cLM-I 4.0 2.2 4.9 2.9 1.0a 0.324 0.18c

WMS-III WMI 66.9 13.5 67.6 12.6 0.1a 0.958 0.01c

Tone Matching Test 29.9 29.2 22.5 27.7 133.5b 0.30 �0.17dWAIS-III POI 77.8 10.6 85.1 17.0 133.0b 0.29 0.17d

WAIS-III PSI 74.7 8.0 83.5 16.2 111.0b 0.08 0.28d

**p b0.01.a F-value (ANOVA).b U-value (Mann–Whitney U).c Pearson Product Moment correlation coefficient with community status.d Spearman Rho Correlation coefficient with community status.

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245242

Of all clinical variables, only SANS total score (with

globals) differed significantly between inpatient and outpa-

tient groups. BPRS total score was not significant.

No neurocognitive variable was found to be significantly

different between inpatient and outpatient groups. WCST-

categories achieved did not reach significance when

corrected for multiple comparisons.

Daily problem-solving skills (ILS-PB) were significantly

different between inpatient and outpatient groups. The mean

scaled score for the inpatient group (31.4) was commensu-

rate with the recommendation for maximum supervision for

individuals scoring below 40; and the outpatient group

(41.6) performance corresponds with the recommended cut-

off score (N40) associated with moderate supervision for

community living as per the test manual.

4. Discussion

4.1. Summary of findings

We found the ILS-PB to be significantly and

uniquely associated with key features of functional

outcome already identified for persons with serious

and persistent mental illness: namely, working mem-

ory and negative symptoms (Velligan et al., 1997). We

also found that community status (inpatient vs.

outpatient) is significantly associated with daily

problem-solving skills (ILS-PB) and negative symp-

toms: that is, inpatients were more impaired (lower

daily problem-solving skills and higher negative

symptoms) and outpatients were less impaired (higher

daily problem-solving skills and fewer negative

symptoms). Since everyday problem solving is part

of an adaptive process that depends on available

information and available energy to generate solutions

to problems (Sinnott, 1989), it seems plausible that

limited cognitive resources and decreased amounts of

affect and interpersonal interactions would be related

to the compromised responses and partial solutions to

life’s daily problems that are associated with the

ability to function in the community. Therefore, we

believe that our findings suggest that knowledge

about an individual’s daily problem-solving skills, in

addition to negative symptoms, improves prediction

of functional outcome.

In addition to gaining perspective on the meaning-

fulness of everyday problem solving (and problem

finding), and the importance of studying this aspect of

functioning in serious mental illness, our findings

replicate earlier studies that demonstrate the utility of

the ILS-PB as a discriminant measure for inpatients

and outpatients with schizophrenia (Revheim and

Medalia, 2004a,b).

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245 243

4.2. Cognition and daily problem-solving skills

Our findings relating the ILS-PB with verbal

memory, working memory and processing speed are

consistent with previous reports of neurocognitive

aspects of functional outcome (Green, 1996; Green

et al., 2000). The significant relationship of the

ILS-PB with an auditory discrimination task (i.e.,

Tone Matching Test) is also consistent with

previous findings in our laboratory. That is, we

have found significant correlations of daily prob-

lem-solving capacity with performance on sensory

processing tasks in the visual and auditory domain

(Butler et al., 2005; Leitman et al., 2005). Stevens

et al. (1998, 2000) also observed differential tone

matching performance between low and high

functioning patients with schizophrenia, suggesting

that tone matching may serve to assess degree of

functional impairment. Given the limited formal

overlap between tone matching and problem-solving

ability, it is unlikely that tone-matching deficits

contribute directly to poor ILS-PB performance.

More likely, both tests index a poor outcome for

the disorder marked by global neurocognitive

dysfunctions. This may be true as well for the

significant relationship we found between the ILS-

PB and our measure of attention (CPT-IP), a well-

known and validated neurocognitive predictor of

schizophrenia in high-risk studies (Cornblatt et al.,

1992).

We did not find the ILS-PB to be related to fine

motor (Grooved Pegboard), or visual memory

(BVMT) processing, which appears consistent with

the differing realms of cognitive processing mea-

sured. On the other hand, we were surprised to

find the ILS-PB was not highly correlated with

WCST, a visual problem-solving measure that has

been related to functional outcome (Lysaker et al.,

1995) and highly associated with working memory

(Gold et al., 1997; Hartman et al., 2003). However,

given the limited variability of our sample for

categories achieved, it cannot be determined

whether the two problem-solving measures are

not related or whether the relationship was con-

strained by the performance of this sample. This is

true of the trend, but lack of significance for

distinguishing WCST performance between inpa-

tients and outpatients.

4.3. Clinical symptoms and daily problem-solving

skills

We did not find the ILS-PB to be related to positive

symptoms. This is consistent with previous studies

that have also not observed a significant relationship

of positive symptoms and either functional outcomes

or neuropsychological performance (Tamminga et al.,

1998). The lack of correlation with positive symptoms

is in contradistinction to the significant correlation

between ILS-PB and negative symptoms ( p b0.001).

4.4. Implications for rehabilitation approaches and

assessment

Despite the current emphasis on psychiatric reha-

bilitation, many patients with schizophrenia remain

unable to reintegrate into the community even with

adequate control of most psychiatric symptoms.

Currently, primary rehabilitation efforts are aimed at

social skills training (Bellack et al., 2004) and various

approaches that target cognitive deficits (Twamley et

al., 2003). However, our findings may suggest that

remediation of problem-solving skills may also be

critical. For example, it may be inadequate to teach

daily living skills, such as phoning for assistance or

how to administer first aid and other performance-

based skills, without teaching the rationale and

reasoning that actually prompts the awareness of the

problem and solution generation.

It remains to be determined whether problem

solving can be remediated directly or can only be

compensated for. In one recent study (Medalia et al.,

2001), problem-solving training techniques using

educational software aimed to improve concept

formation, reasoning, sequencing, self-monitoring,

working memory, and cognitive flexibility were used

to treat problem-solving deficits in individuals with

schizophrenia. The intervention was found to be

effective in improving problem-solving skills required

for independent living. This remediation result,

however, remains to be replicated.

In contrast, another current study employed error-

less learning techniques to improve social problem-

solving deficits (Kern et al., 2005). The researchers

found their skills training intervention, which

bypassed problem-identification deficits that occur in

schizophrenia, to be successful. This strategy assumes

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245244

that deficient problem-solving skills cannot be reme-

diated and must be overcome with compensatory

techniques.

Nevertheless, whatever core remediation strategy is

used, present findings suggest that improvement in

problem-solving ability as assessed by the ILS-PB

would be expected to lead to improved functional

outcome. The ILS-PB, therefore, may be an appro-

priate instrument for assessing upward generalization

of core cognitive remediation strategies.

By itself, the ILS-PB may be a useful alternative

method for describing an individual’s level of

neurocognitive functioning. In addition to its prag-

matism and good face validity with persons with

serious mental illness, its predictive value of

community status (inpatient vs. outpatient) compared

to other neurocognitive measures is promising. An

evaluation tool, such as the ILS-PB, can be

construed as a means of detecting strengths, as well

as deficits, and is user-friendly with clients who are

continually focused on their clinical pathology and

impaired thinking during standardized interviews and

neuropsychological testing.

In settings that do not require full symptomatic or

neuropsychological evaluations, ILS-PB may indeed

serve as a useful alternative measure for functional

outcome in schizophrenia. This is especially true for

individuals across a variety of residential placements

and living conditions because the measure is not

dependent on skills training or related to a specific

performance context. As such, the ILS-PB may be a

useful proxy measure in groups, such as forensic

patients, where functional status may be divorced

from functional capacity.

4.5. Study limitations and future directions

Limitations of our study include the cross-sectional

nature of data collection, the small sample size and the

specificity of the demographic characteristics (persis-

tently ill, middle-aged males) that limit generalizabil-

ity. Furthermore, the ILS-PB was not cross-validated

with an alternate measure of daily problem-solving

skills. Therefore, it remains to be determined whether

ILS-PB can be used as a predictor for characteristics

such as dischargeability or the ability to function in

less restrictive environments. We did, however,

demonstrate that the inpatients and outpatients in

our sample were significantly different in terms of

community tenure. While it may not be surprising that

the ILS-PB differentiates daily problem-solving levels

between patient groups because of the respective

opportunities to practice daily living skills in context,

it nonetheless illustrates how the underlying cognitive

mechanisms of reasoning may be as important as the

actual performance of daily living tasks. Furthermore,

many of the items on the ILS-PB are relevant for

inpatients as well as outpatients (e.g. name 2 reasons

why it is important to have relationships with people),

insofar as tests that rely on memory for items on a

shopping list (e.g. CVLT) are equally valid. Cross-

validation of the ILS-PB with other standardized

functional outcome measures currently used in

schizophrenia research is compelling.

Acknowledgements

The authors would like to thank Ali Saperstein and

Maria Jalbrzikowski for assisting with the project.

This study was made possible with grant support

from NIMH, R01-MH049334-12, awarded to DCJ.

References

Ammons, R.B., Ammons, C.H., 1962. The quick test (QT):

provisional manual. Psychol. Rep. 11, 111–161.

Andreasen, N.C., 1981. Scale for the Assessment of Negative

Symptoms (SANS). University of Iowa, Iowa City.

Bellack, A.S., Mueser, K.T., Gingerich, S., Agresta, J., 2004. Social

Skills Training for Schizophrenia. The Guilford Press, New

York.

Berman, I., Viegner, B., Merson, A., Allan, E., Pappas, D., Green,

A.I., 1997. Differential relationships between positive and

negative symptoms and neuropsychological deficits in schizo-

phrenia. Schizophr. Res. 25, 1–10.

Butler, P.D., Zemon, V., Schechter, I., Saperstein, A.M., Hoptman,

M.J., Lim, K.O., Revheim, N., Silipo, G., Javitt, D.C., 2005.

Early-stage visual processing and cortical amplification deficits

in schizophrenia. Arch. Gen. Psychiatry 62, 495–504.

Cornblatt, B.A., Lenzenweger, M.F., Dworkin, R.H., Erlenmeyer-

Kimling, L., 1992. Childhood attentional dysfunctions predict

social deficits in unaffected adults at risk for schizophrenia. Br.

J. Psychiatry, 59–64.

Dickinson, D., Coursey, R.D., 2002. Independence and overlap

among neurocognitive correlates of community functioning in

schizophrenia. Schizophr. Res. 56, 161–170.

Evans, J.D., Heaton, R.K., Paulsen, J.S., Palmer, B.W., Patterson,

T., Jeste, D.V., 2003. The relationship of neuropsychological

N. Revheim et al. / Schizophrenia Research 83 (2006) 237–245 245

abilities to specific domains of functional capacity in older

schizophrenia patients. Biol. Psychiatr. 53, 422–430.

Gold, J.M., Carpenter, C., Randolph, C., Goldberg, T.E., Wein-

berger, D.R., 1997. Auditory working memory and Wisconsin

Card Sorting Test performance in schizophrenia. Arch. Gen.

Psychiatry 54, 159–165.

Gold, J.M., Goldberg, R.W., McNary, S.W., Dixon, L.B., Lehman,

A.F., 2002. Cognitive correlates of job tenure among patients

with severe mental illness. Am. J. Psychiatr. 159, 1395–1402.

Green, M.F., 1996. What are the functional consequences of

neurocognitive deficits in schizophrenia? Am. J. Psychiatr.

153, 321–330.

Green, M.F., Kern, R.S., Braff, D.L., Mintz, J., 2000. Neuro-

cognitive deficits and functional outcome in schizophrenia: are

we measuring the bright stuffQ? Schizophr. Bull. 26, 119–136.

Hartman, M., Steketee, M.C., Silva, S., Lanning, K., Andersson, C.,

2003. Wisconsin card sorting test performance in schizophrenia:

the role of working memory. Schizophr. Res. 63, 201–217.

Harvey, P.D., Sukhodolsky, D., Parrella, M., White, L., Davidson,

M., 1997. The association between adaptive and cognitive

deficits in geriatric chronic schizophrenia patients. Schizophr.

Res. 27, 211–218.

Kern, R.S., Green, M.F., Mitchell, S., Kopelowicz, A., Mintz, J.,

Liberman, R.P., 2005. Extensions of errorless learning for social

problem-solving deficits in schizophrenia. Am J. Psychiatr. 162,

513–519.

Leitman, D., Foxe, J.J., Butler, P.D., Saperstein, A., Ravheim, N.,

Javitt, D.C., 2005. Sensory contributions to impaired prosodic

processing in schizophrenia. Biol. Psychiatr. 58, 56–61.

Loeb, P.A., 1996. ILS: Independent Living Scales Manual. The

Psychological Corporation, San Antonio.

Lysaker, P.H., Bell, M.D., Bioty, S.M., 1995. Cognitive deficits in

schizophrenia: prediction of symptoms change for participators

in work rehabilitation. J. Nerv. Ment. Dis. 183, 332–336.

McGurk, S.R., Moriarty, P.J., Harvey, P.D., Parrella, M., White, L.,

Friedman, J., Davis, K.L., 2000. Relationship of cognitive

functioning, adaptive life skills, and negative symptom severity

in poor-outcome geriatric schizophrenia patients. J Neuopsy-

chiatr. Clin. Neurosci. 12, 257–263.

Medalia, A., Revheim, N., Casey, M., 2001. The remediation of

problem-solving skills in schizophrenia. Schizophr. Bull. 27,

259–267.

O’Leary, D.S., Flaum, M., Kesler, M.L., Flashman, L.A., Arndt, S.,

Andreasen, N.C., 2000. Cognitive correlates of the negative,

disorganized, and psychotic symptom dimension of schizophre-

nia. J. Neurospychiatr. Clin. Neurosci. 12, 4–14.

Overall, J.E., Gorham, D.R., 1962. The brief psychiatric rating

scale. Psychol. Rep. 10, 799–812.

Revheim, N., Medalia, A., 2004a. Verbal memory, problem-solving

skills and community status in schizophrenia. Schizophr. Res.

68, 149–158.

Revheim, N., Medalia, A., 2004b. The Independent Living Scales

(ILS) as a measure of functional outcome for schizophrenia.

Psychiatr. Serv. 55, 1052–1054.

Sinnott, J.D., 1989. Summary: issues and directions for everyday

problem solving research. In: Sinnott, J.D. (Ed.), Everyday

Problem Solving: Theories and Applications. Praeger, New

York, pp. 300–306.

Stevens, A.A., Goldman-Rakic, P.S., Gore, J.C., Fulbright, R.K.,

Wexler, B.E., 1998. Cortical dysfunction in schizophrenia

during auditory word and tone working memory demonstrated

by functional magnetic resonance imaging. Arch. Gen. Psychi-

atry 55, 1097–1103.

Stevens, A.A., Donegan, N.H., Anderson, M., Goldman-Rakic, P.S.,

Wexler, B.E., 2000. Verbal processing deficits in schizophrenia.

J. Abnorm. Psychology 190, 461–471.

Suslow, T., Junghanns, K., Weitzsch, C., Arolt, V., 1998. Relations

between neuropsychological vulnerability markers and negative

symptoms in schizophrenia. Psychopathology 31, 178–187.

Tamminga, C.A., Buchanan, R.W., Gold, J.M., 1998. The role of

negative symptoms and cognitive dysfunction in schizophrenia

outcome. Int. Clin. Psychopharmacol. 13, S21–S26.

Twamley, E.W., Doshi, R.R., Nayak, G.V., Palmer, B.W., Golshan,

S., Heaton, R.K., Patterson, T.L., Jeste, D.V., 2002. Generalized

cognitive impairments, ability to perform everyday tasks, and

level of independence in community living situations of older

patients with psychosis. Am. J. Psychiatr. 159, 2013–2020.

Twamley, E.W., Jeste, D.V., Bellack, A.S., 2003. A review

of cognitive training in schizophrenia. Schizophr. Bull. 29,

359–382.

Velligan, D.I., Mahurin, R.K., Diamond, P.L., Hazleton, B.C.,

Eckert, S.L., Miller, A.L., 1997. The functional significance of

symptomatology and cognitive function in schizophrenia.

Schizophr. Res. 25, 21–31.

Wechsler, D., 1997a. The Wechsler Adult Intelligence Scale, Third

ed. The Psychological Corporation, San Antonio.

Wechsler, D., 1997b. The Wechsler Memory Scale-III. The

Psychological Corporation, San Antonio.