Does cognition predict community function only in schizophrenia?: a study of schizophrenia patients, bipolar affective disorder patients, and community control subjects

Cognitive deficits predict functioning in schizophrenia; however, little is known as to whether the association is present in other mental disorders. If specific cognitive deficits uniquely predict functional impairment in schizophrenia the association of select aspects of brain dysfunction with daily living would suggest an intervention target and perhaps a means by which to improve the functioning of schizophrenia patients. The relationship of cognition and functioning was investigated in schizophrenia (n=39), bipolar affective disorder (n=27), and nonpsychiatric control (n=38) participants to determine whether the associations varied across groups. We examined verbal memory, verbal learning, verbal fluency, vigilance, executive functioning, symptomatology, and generalized cognitive functioning for associations with social function. Correlational analyses revealed particular cognitive domains (e.g., verbal memory) to be associated with social functioning in schizophrenia, bipolar, and control subjects; however generalized cognitive function and symptomatology were also associated with social functioning in patients. Multiple regression analyses revealed that in schizophrenia poor verbal memory predicted worse social functioning even after the effects of generalized cognitive dysfunction were considered. Verbal memory indices failed to account for variance in social function in bipolar patients and control subjects after consideration of generalized cognitive function. Bipolar patients with worse planning and problem solving tended to have worse social functioning. Therefore, unlike schizophrenia patients who may fail to process verbally mediated material, bipolar patients' difficulty with logical approaches to problems in daily living may have the greatest impact on their community function.     

Social/communication skills, cognition, and vocational functioning in schizophrenia

Deficits in social/communications skills have been documented in schizophrenia, but it is unclear how these deficits relate to cognitive deficits and to everyday functioning. In the current study, social/communication skills performance was measured in 29 schizophrenia patients with a history of good vocational functioning (GVF) and 26 with a history of poor vocational functioning (PVF) using a role-play-based social skills assessment, the Maryland Assessment of Social Competence (MASC). A battery of standard cognitive tasks was also administered. MASC-indexed social skills were significantly impaired in PVF relative to GVF patients (odds ratio = 3.61, P < .001). Although MASC social skills performance was significantly associated with cognitive performance in domains of verbal ability, processing speed, and memory, the MASC nevertheless remained an independent predictor of vocational functioning even after controlling for cognitive performance. Social/communications skills predict vocational functioning history independently of cognitive performance, and social skills measures should be considered for inclusion in test batteries designed to predict everyday functioning in schizophrenia.     

Reality monitoring and its association with social functioning in schizophrenia

Reality monitoring, or the ability to discriminate internal from external information present in short-term memory, is relevant in the study of schizophrenia. Previous research has linked monitoring impairments with psychotic symptoms and certain forms of communication disturbance. The focus of the present study was to test the hypothesis that there would be specific relationships between reality monitoring in patients with schizophrenia and current and pre-morbid social functioning, beyond the effects of general verbal ability. Fifty outpatients with schizophrenia or schizoaffective disorder were assessed for internal/external reality monitoring deficits, general verbal intelligence, and both current and pre-morbid social functioning. Associations between these variables were assessed. Exploratory analyses also were conducted to determine whether specific types of reality monitoring errors were related to social functioning. Results showed that (a) overall accuracy in reality monitoring was related to pre-morbid social functioning beyond the effects of verbal ability, (b) sensitivity to old versus new information in reality monitoring was related to current social functioning, and (c) a say-report-think reality monitoring error was significantly associated with pre-morbid social functioning. The results support the hypothesis of an association between reality monitoring sensitivity and social functioning.     

Verbal memory, problem-solving skills and community status in schizophrenia

Neuropsychological deficits have been associated with poor community functioning in individuals with schizophrenia. Previous research suggests that verbal memory capacity is related to functional capacity. The purpose of this study was to investigate the relationship between verbal memory, problem-solving skills and community functioning, as measured by treatment status (inpatient vs. outpatient) in people with schizophrenia spectrum disorders. Evaluations were done on 162 individuals with schizophrenia or schizoaffective disorder, seen in inpatient (n=87) and outpatient settings (n=75). Verbal memory was assessed using narrative recall and list recall measures. Problem-solving skills for independent living were assessed using a social reasoning measure and a daily problem-solving skills measure. Better verbal memory performance was associated with better problem solving for independent living. However, inpatient vs. outpatient status was best determined by problem-solving skills for independent living rather than verbal memory performance. The results reveal the importance of daily problem-solving skills for community status in schizophrenia. Although verbal memory performance is associated with problem-solving skills for independent living, predictive probability of community status does not improve when memory performance is taken into account.     

The crucial role of sustained attention in community functioning in outpatients with schizophrenia

The aim was to explore the pattern of associations between visual cognitive performance and community functioning in a sample of outpatients with schizophrenia participating in a rehabilitation program. Visuo-spatial tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to assess cognitive performances in 88 subjects. The Multnomah Community Ability Scale (MCAS) was used to measure dimensions of community functioning. Our results showed that the sustained attention score was significantly associated with the global community functioning score and with two specific dimensions: "adjustment to living" and "behavioral problems". No association was found between other cognitive indices and MCAS scores. Since the sustained attention task mainly involves the executive component of working memory, these findings suggest that attentional control processes are limiting factors for community functioning in schizophrenia outpatients. Measures of such processes could serve as key indices of disability in clinical practice. Attention and working memory training may be helpful to improve community functioning in subjects with schizophrenia.     

Neurocognition and cognitive biases in schizophrenia

ABSTRACT: Individuals with schizophrenia have been found to exhibit a number of information processing biases that may play a role in the development and exacerbation of symptoms and may impair overall functioning. However, little is known about the factors that are associated with these cognitive biases. Recently, researchers have begun to consider whether neurocognitive deficits, common in schizophrenia, may be risk factors for the development of cognitive biases. In the present study, we assessed neurocognition (verbal learning, delayed verbal recall memory, and verbal recognition memory) and cognitive biases (knowledge corruption and impaired cognitive insight) in 72 individuals with schizophrenia or schizoaffective disorder. As hypothesized, poorer delayed verbal recall memory was associated with increased knowledge corruption. Contrary to expectations, verbal learning and verbal memory were not associated with cognitive insight. These findings suggest that an inadequate recall memory system may put patients with schizophrenia at greater risk for cognitive distortions.     

Correlations of functional capacity and neuropsychological performance in older patients with schizophrenia: Evidence for specificity of relationships?

BACKGROUND: Neuropsychological (NP) performance is a consistent correlate of everyday functioning in schizophrenia, but it is unclear whether relationships between individual NP ability areas and domains of everyday functioning are general or specific. Assessments of real-world everyday functioning may be influenced by environmental and social factors (e.g., social security, disability status, opportunities and restrictions in living situations). This study examined the specificity of the relationships between different NP abilities and performance-based measures of social and living skills. METHODS: 181 ambulatory older (age>50) patients with schizophrenia were examined with NP tests measuring episodic and working memory, executive functioning, verbal fluency, and processing speed. All subjects performed tasks examining social (Social Skills Performance Assessment: SSPA) and everyday living (UCSD Performance Based Skills Assessment: UPSA) skills. RESULTS: Using canonical analysis, the NP variables were used to predict the functional capacity measures. The analysis found that 37% of the variance in the functional capacity and NP measures was shared, X(2) (54)=106.29, p<.001. Two canonical roots described the cognitive variables and the roots were differentially associated with everyday living and social skills. The root loading on processing speed, episodic memory, and executive functions were associated with UPSA scores, while the root loading on working and episodic memory and verbal fluency were associated most strongly with social competence. IMPLICATIONS: Social and everyday living skills deficits in patients with schizophrenia may reflect generally independent domains of functional outcome, linked through cognitive performance. The data suggest that somewhat different cognitive processes are associated with these two domains of functional capacity, although there appears to be some overlap, which may be due to the nature of the NP tests employed.     

Auditory verbal hallucinations and cognitive functioning in healthy individuals

Auditory verbal hallucinations (AVH) are a characteristic symptom in schizophrenia, and also occur in the general, non-clinical population. In schizophrenia patients, several specific cognitive deficits, such as in speech processing, working memory, source memory, attention, inhibition, episodic memory and self-monitoring have been associated with auditory verbal hallucinations. Such associations are interesting, as they may identify specific cognitive traits that constitute a predisposition for AVH. However, it is difficult to disentangle a specific relation with AVH in patients with schizophrenia, as so many other factors can affect the performance on cognitive tests. Examining the cognitive profile of healthy individuals experiencing AVH may reveal a more direct association between AVH and aberrant cognitive functioning in a specific domain. For the current study, performance in executive functioning, memory (both short- and long-term), processing speed, spatial ability, lexical access, abstract reasoning, language and intelligence performance was compared between 101 healthy individuals with AVH and 101 healthy controls, matched for gender, age, handedness and education. Although performance of both groups was within the normal range, not clinically impaired, significant differences between the groups were found in the verbal domain as well as in executive functioning. Performance on all other cognitive domains was similar in both groups. The predisposition to experience AVH is associated with lower performance in executive functioning and aberrant language performance. This association might be related to difficulties in the inhibition of irrelevant verbal information.     

The relations between cognition and the independent living skill of shopping in people with schizophrenia

A great deal of interest has developed regarding the impact of cognitive deficits on the everyday functioning of people with schizophrenia. This study examined the relationships between cognitive functioning and the performance of a specific independent living skill (grocery shopping) in a sample of 73 individuals with schizophrenia or schizoaffective disorder. Cognitive variables included tests of verbal memory, executive functioning, verbal fluency, sustained attention and visual motor skill. Functional outcome was measured with the Test of Grocery Shopping Skills, which is an ecologically based performance measure that requires participants to shop for 10 items within an actual grocery store. Accuracy on the shopping task was significantly associated with fewer perseverative responses on the Wisconsin Card Sorting Test, better verbal memory and faster processing speed. Shopping efficiency (i.e. less redundancy) was associated with better performance on several cognitive tasks, including verbal memory, verbal fluency, sustained attention and executive functioning. Results of this study extend previous research by examining the relation between cognition and the actual performance of daily living skills under natural circumstances.     

Cognitive functioning in young people with first episode psychosis: relationship to diagnosis and clinical characteristics

OBJECTIVE: To examine the extent and nature of neuropsychological deficits in adolescents and young people with first episode psychosis (FEP), and to determine whether the pattern and extent of neuropsychological deficits varied according to diagnosis. METHOD: A total of 83 FEP subjects aged 13-25 years, and 31 healthy controls completed a comprehensive battery of neuropsychological tests, grouped into 10 cognitive domains. First episode psychosis subjects were stratified into three diagnostic groups (schizophrenia, affective disorders, substance-induced psychosis) and differences in cognitive profiles were examined. The contribution of demographic and clinical characteristics to cognitive performance was also explored. RESULTS: The schizophrenia group demonstrated significantly worse performance on tasks of verbal learning and memory than the affective disorders group. Compared to healthy controls, the schizophrenia group also demonstrated global impairment across the majority of cognitive domains. The substance-induced group's performance lay between that of the schizophrenia and affective disorders groups. Analyses of differential deficits revealed that verbal learning, verbal memory and current intellectual functioning were selectively impaired in the schizophrenia group, whereas the affective disorders group demonstrated a selective deficit in speeded processing. Premorbid intellectual functioning, negative symptomatology and medication levels were the strongest predictors of cognitive performance in FEP subjects. CONCLUSIONS: Verbal memory deficits differentiate individuals with schizophrenia from those with psychotic affective disorders. Although significant cognitive deficits are evident across all diagnostic FEP groups, individuals with schizophrenia appear to have more generalized impairment across a broad array of cognitive functions than other psychotic diagnoses. Lower premorbid intellectual functioning does not appear to contribute to greater cognitive deterioration following onset of psychosis, but severity of illness may be a more important factor than levels of mood disturbance.     

Auditory working memory and verbal recall memory in schizotypy

Deficits on verbal memory tasks, as well as on spatial and auditory working memory tasks, have been observed in schizophrenia patients. A useful strategy in the determination of the premorbid indicator status of specific cognitive and memory deficits observed in patients is to examine those persons at increased biological risk for schizophrenia (e.g. first-degree relatives), schizotypal personality disorder patients, and/or psychometrically identified schizotypes for comparable deficits, though perhaps less profound than those seen in actual patients. We examined verbal memory and auditory working memory functioning in 31 schizotypic and 26 normal control subjects from a large randomly ascertained non-clinical university population. Schizotypy status was determined psychometrically using the well-known Perceptual Aberration Scale. Contrary to our theory-guided expectations, noteworthy deficits in verbal memory and auditory working memory were not observed in the schizotypic subjects and the two experimental groups did not differ significantly on any of the memory measures. These results were discussed in light of prior results obtained using the spatial delayed response task (i.e. spatial working memory) and Wisconsin Card Sorting Test performance on these same subjects. The theoretical implications of these findings are discussed in relation to the putative processes involved in the working memory system, as well as in relation to the schizotypy construct.     

Neurocognitive performance and functional disability in the psychosis prodrome

OBJECTIVE: This study evaluates the pattern of neuropsychological deficits and their association with clinical symptomatology and social functioning in individuals identified as ultra-high-risk (UHR) for psychosis. METHODS: A sample of 45 UHR individuals was identified using the Structured Interview for Prodromal Syndromes (SIPS) from consecutive referrals to the Staglin Music Festival Center for the Assessment and Prevention of Prodromal States (CAPPS) at UCLA. Participants were administered a neurocognitive test battery, as well as measures of global (Strauss-Carpenter Outcome Scale) and social functioning (UCLA Social Attainment Survey). RESULTS: Participants showed significant deficits in speed of processing, verbal learning and memory, and motor speed. Poorer verbal learning and memory performance was significantly associated with poorer social functioning, and there was a trend for poorer performance on reasoning and problem solving to be associated with poorer global functioning. Verbal memory independently predicted social functioning over and above severity of negative symptoms. Cognitive deficits were not associated with severity of clinical symptomatology. CONCLUSIONS: Despite the absence of fully psychotic symptoms, UHR individuals experience significant cognitive deficits, particularly on tasks requiring speeded information-processing and efficient recall from memory, and these deficits appear to be associated with functional disability in a manner parallel to that observed in patients with established psychotic illness.     

Neurocognitive performance and negative symptoms: are they equal in explaining disability in schizophrenia outpatients?

OBJECTIVE: The aim of this study is to assess if cognitive variables and symptom dimensions can predict disability in a sample of outpatients with schizophrenia. METHOD: A cross-sectional sample of 113 individuals with a diagnosis of schizophrenia (DSM-IV criteria) was selected from a computerized register of five Community Mental Health Centers. Patients were assessed by two trained psychologists, with a neuropsychological battery comprising measures for verbal memory, attention, operative memory and abstraction and flexibility functions. Symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS); a socio-demographic and clinical questionnaire, comprising the Disability Assessment Scale (DAS), was also completed. Test scores were standardized (t scores) to performance of healthy controls. To assess the relationship between clinical and sociodemographic factors and disability and cognitive functioning Pearson's correlation coefficients were computed. In order to establish the predictive capacity of the cognitive, clinical and symptom variables on disability linear regression models were fitted. RESULTS: Mean age of patients was 41.6 years and 68% were male. Higher ratings in the negative dimension were associated with more cognitive deficits. Association with the positive dimension was present but less strong. All disability areas, except for disability in occupational functioning, were partially explained by the negative dimension. Disability in family functioning was also partially explained by attention and number of admissions since onset. CONCLUSION: Negative symptoms are the major source of disability of our sample and are also associated to cognitive functioning. The present findings suggest that further investigation on the mediators between clinical and social outcomes may help to design specific treatments to reduce disability.     

Neurocognitive and social functioning in schizophrenia

This cross-sectional study examined the relationships between neurocognitive and social functioning in a sample of 80 outpatients with DSM-III-R schizophrenia. The neurocognitive battery included measures of verbal ability, verbal memory, visual memory, executive functioning, visual-spatial organization, vigilance, and early information processing. Positive and negative symptoms were assessed with the Positive and Negative Syndrome Scale. A range of social behaviors were assessed using the Social Functioning Scale (SFS), the Quality of Life Scale (QLS), and a video-based test, the Assessment of Interpersonal Problem-Solving Skills (AIPSS). Social functioning as assessed by the SFS was unrelated to neurocognitive functioning. Poor cognitive flexibility was associated with low scores on the QLS and the AIPSS. Verbal ability and verbal memory were also significantly associated with the AIPSS. Visual-spatial ability and vigilance were associated with the sending skills subscale of the AIPSS. In this study, which used a wide range of neurocognitive tests and measures of community functioning and social problem solving, results support earlier research that suggests an association between certain aspects of neurocognitive functioning and social functioning.     

Neuropsychological functioning in early onset psychotic disorders

This paper examines whether neuropsychological profiles of youth with early onset psychotic disorders predicted diagnostic or clinical status. Youth with schizophrenia (n=27), bipolar disorder (n=22), and psychosis NOS (n=20) were included. Subjects received an extensive neuropsychological evaluation, including measures of general cognition, attention, memory, and executive functioning. Medication status was not controlled. No statistically significant neurocognitive differences across diagnostic groups were found. Compared to standardized norms, youth with schizophrenia demonstrated deficits in general cognition, verbal learning, recall, sustained effort, and social knowledge. Subjects with bipolar disorder and psychosis NOS exhibited deficits on measures of verbal learning, recall, and sustained effort similar to those of youth with schizophrenia. Neurocognitive deficits in memory and attention appeared to be common among youth with psychotic illnesses, regardless of diagnosis. Those with schizophrenia may have greater global cognitive deficits and problems with social knowledge. Across diagnoses, subjects demonstrated relative strengths on tests that provided them with immediate feedback, and performed most poorly on tests requiring delayed recall.     

Relationship between psychopathology and cognitive functioning in schizophrenia

The purpose of this study was to delineate the relationship between positive, negative, cognitive, depressive, and excitement symptom dimensions of schizophrenia and cognitive functioning. Fifty-eight patients with schizophrenia (DSM-IV criteria) were assessed using the Positive and Negative Syndrome Scale (PANSS) and a battery of neuropsychological tests (executive function/abstraction, verbal and spatial working memory, verbal and nonverbal memory/learning, attention, visuospatial ability, and psychomotor speed). The cognitive symptom dimension correlated with executive functions, attention, verbal memory, and spatial ability. Severity of the negative symptom dimension was related to impairment in the structure of the semantic knowledge system, verbal memory, and auditory attention. In contrast, severity of the positive symptom dimension correlated only with impairment in the structure of the semantic knowledge system, and psychomotor speed. Finally, severity of the depressive and excitement symptom dimension was not associated with cognition. Correlations between symptom dimensions and cognitive measures were at best modest. Severity of cognitive and negative symptoms was mainly correlated with deficits on executive functions, semantic memory, and verbal memory, while positive symptoms only with semantic memory. These correlations were modest, suggesting that psychopathology and cognitive deficits in schizophrenia are caused, at least partially, by distinct pathophysiological processes.     

Contribution of divergent thinking to community functioning in schizophrenia

Fluency deficits have been associated with poor community functioning in patients with schizophrenia. In our previous study we demonstrated that the ability to generate higher-quality responses on tasks of divergent thinking as measured by several fluency tests was impaired in patients with schizophrenia. The purpose of the present study was to investigate the contribution of the deficits in divergent thinking to community dysfunction in schizophrenia. Forty Japanese outpatients with schizophrenia and 32 healthy control subjects were recruited for this study and assessed over a broad spectrum of the neurocognitive domain. Their capacity for divergent thinking was assessed by idea, design, and word fluency tests. Community functioning was assessed by using the Global Assessment of Functioning (GAF), the Life Assessment Scale for the Mentally Ill (LASMI), and the Social Functioning Scale (SFS). The results confirmed the qualitative deficits of divergent thinking in schizophrenia. Stepwise multiple regressions using neurocognitive and demographic/clinical variables as predictors revealed that the higher-quality response scores on the tasks of divergent thinking significantly contributed to community functioning. Moreover, the deficit on the verbal task of divergent thinking significantly contributed to impairment in the area of daily living, and the deficit on the nonverbal task of divergent thinking significantly contributed to impairment in the area of interpersonal relations. The results of this study reveal the importance and the possibility of cognitive remediation and cognitive training with strategies that target capacity for divergent thinking to improve community functioning in patients with schizophrenia.     

Cognitive and clinical predictors of success in vocational rehabilitation in schizophrenia

Cognitive impairments in schizophrenia appear to be associated with social problem solving, social and vocational functioning, and psychosocial skill acquisition. The present study examined the relationship of cognitive functioning, as well as clinical symptoms, to vocational outcomes among individuals with schizophrenia. One hundred and twelve participants with DSM-IV schizophrenia spectrum diagnoses underwent a comprehensive neuropsychiatric evaluation after enrolling in one of several employment programs. The neuropsychological evaluation examined verbal learning and memory, attention, speed of information processing, and executive functioning. Clinical symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS). Vocational outcomes were assessed 4 months after baseline assessment and included both measures of employment outcome (e.g., earnings) and of work performance as assessed by the Work Behavior Inventory (WBI). Negative symptoms, learning and memory performance, processing speed, and executive functioning were related to hours, weeks, and wages earned on the job. Stepwise multiple regression analyses found that among baseline clinical and cognitive predictors, only verbal learning and memory and cognitive disorganization symptoms were significant predictors of work behaviors 4 months later. Learning and memory were the only significant predictors of integrated employment at 4 months. These results suggest specific aspects of cognition may be modestly predictive of vocational outcomes.     

Daily activities, cognition and community functioning in persons with schizophrenia

OBJECTIVE: This cross-sectional study explored the relationships between daily activity performance, attention, memory, executive functions and community functioning in people with schizophrenia. More specifically, this study attempted to verify the hypothesis that functional limitations in the performance of daily activities negatively affect community functioning in people with schizophrenia. METHODS: Eighty-two individuals with schizophrenia living in the community were recruited for the study. The Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis was used to assess participants' functional capacity during a meal preparation task. Visuo-spatial associative memory, spatial working memory, planning, visuo-motor coordination, and selective attention were evaluated as well. Community functioning was assessed with the Independent Living Skills Survey (ILSS) and the Multnomah Community Ability Scale (MCAS). RESULTS: Correlations revealed significant associations between functional capacity and visuo-spatial associative learning, spatial working memory, planning and negative symptoms. Planning skills during meal preparation were found to be associated with MCAS. After regression analyses, only visuo-spatial memory, negative symptoms, education and familiarity with meal preparation explained variation in functional capacity. CONCLUSIONS: The findings of the current study suggest that visuo-spatial associative learning, negative symptoms, education and familiarity with task are among the important factors for functional capacity. Planning skills necessary for efficient task performance were also found to be those most determinant for community functioning. Rehabilitation interventions should consider these underlying strength and deficits when developing strategies to help people with schizophrenia build functional skills essential for community living.     

Cognitive deficits in relatives of patients with schizophrenia: a meta-analysis

BACKGROUND: Schizophrenia is characterized by a generalized cognitive impairment with pronounced deficits in the domains of verbal memory, executive functioning and attention. AIM: To investigate whether cognitive deficits found in patients with schizophrenia are also found in non-affected relatives. METHOD: A meta-analytic review of the published literature on cognitive performance between relatives of schizophrenic patients and healthy controls. RESULTS: The meta-analyses yielded nine weighted effect sizes from 37 studies comprising 1639 relatives of schizophrenia patients and 1380 control subjects. The largest differences were found on verbal memory recall (d=0.54, 95% CI=0.43-0.66) and executive functioning (d=0.51, 0.36-0.67). Attentional functioning showed smaller effect sizes (d=0.28, 0.06-0.50). These effect sizes are in the moderate range. CONCLUSION: Cognitive deficits found in patients with schizophrenia are also found in non-affected relatives. This finding is consistent with the idea that certain cognitive deficiencies in relatives are caused by familial predisposition to schizophrenia and that these deficiencies might be putative endophenotypes for schizophrenia. However, our results do not address genetic causes directly. Further work is needed to determine whether certain cognitive traits are familial and whether there is co-inheritance of these traits with schizophrenia within families.