A path model investigation of neurocognition, theory of mind, social competence, negative symptoms and real-world functioning in schizophrenia

Problems in real-world functioning are pervasive in schizophrenia and much recent effort has been devoted to uncovering factors which contribute to poor functioning. The goal of this study was to examine the role of four such factors: social cognition (theory of mind), neurocognition, negative symptoms, and functional capacity (social competence). 178 individuals with schizophrenia or schizoaffective disorder completed measures of theory of mind, neurocognition, negative symptoms, social competence, and self-reported functioning. Path models sought to determine the relationships among these variables. Theory of mind as indexed by the Hinting Task partially mediated the relationship between neurocognition and social competence, and negative symptoms and social competence demonstrated significant direct paths with self-reported functioning. Study results suggest theory of mind serves as an important mediator in addition to previously investigated social cognitive domains of emotional and social perception. The current study also highlights the need to determine variables which mediate the relationship between functional capacity and real-world functioning.     

The Relationship of Attitudinal Beliefs to Negative Symptoms,Neurocognition, and Daily Functioning in Recent-Onset Schizophrenia

Background: In the early course of schizophrenia, premorbid functioning, negative symptoms, and neurocognition have been robustly associated with several domains of daily functioning. Research with chronic schizophrenia patients suggests that attitudinal beliefs may influence daily functioning. However, these relationships have not been examined in recent-onset schizophrenia patients. Methods: The sample consisted of recent-onset schizophrenia outpatients (n = 71) who were on average 21.7 (SD = 3.3) years old, had 12.5 (SD = 1.8) years of education, and 5.9 (SD = 6.3) months since psychosis onset. Patients were assessed for premorbid adjustment, positive and negative symptoms, neurocognition, attitudinal beliefs, and daily functioning. Normal controls (n = 20) were screened for psychopathology and demographically matched to the patients. Results: Comparisons indicated that recent-onset patients had higher levels of dysfunctional attitudes and lower self-efficacy compared to healthy controls (t = 3.35, P < .01; t = −4.1, P < .01, respectively). Dysfunctional attitudes (r = −.34) and self-efficacy (r = .36) were significantly correlated with daily functioning. Negative symptoms were found to mediate the relationship between self-efficacy and daily functioning (Sobel test, P < .01), as well as between dysfunctional attitudes and daily functioning (Sobel test, P < .05). Neurocognition was a significant mediator of the relationship between self-efficacy and daily functioning (Sobel test, P < .05). Discussion: Early course schizophrenia patients have significantly more dysfunctional attitudes and lower self-efficacy than healthy subjects. Both self-efficacy and dysfunctional attitudes partially contribute to negative symptoms, which in turn influence daily functioning. In addition, self-efficacy partially contributes to neurocognition, which in turn influences daily functioning.Key words: recent-onset schizophrenia, dysfunctional attitudes, self-efficacy, negative symptoms, neurocognition, daily functioning, mediation models, premorbid history     

Social cognition in schizophrenia, Part 2: 12-month stability and prediction of functional outcome in first-episode patients

This study evaluated the longitudinal stability and functional correlates of social cognition during the early course of schizophrenia. Fifty-five first-episode schizophrenia patients completed baseline and 12-month follow-up assessments of 3 key domains of social cognition (emotional processing, theory of mind, and social/relationship perception), as well as clinical ratings of real-world functioning and symptoms. Scores on all 3 social cognitive tests demonstrated good longitudinal stability with test-retest correlations exceeding .70. Higher baseline and 12-month social cognition scores were both robustly associated with significantly better work functioning, independent living, and social functioning at the 12-month follow-up assessment. Furthermore, cross-lagged panel analyses were consistent with a causal model in which baseline social cognition drove later functional outcome in the domain of work, above and beyond the contribution of symptoms. Social cognitive impairments are relatively stable, functionally relevant features of early schizophrenia. These results extend findings from a companion study, which showed stable impairments across patients in prodromal, first-episode, and chronic phases of illness on the same measures. Social cognitive impairments may serve as useful vulnerability indicators and early clinical intervention targets.     

Social Disinterest Attitudes and Group Cognitive-Behavioral Social Skills Training for Functional Disability in Schizophrenia

The majority of clinical trials of cognitive-behavioral therapy (CBT) for schizophrenia have used individual therapy to target positive symptoms. Promising results have been found, however, for group CBT interventions and other treatment targets like psychosocial functioning. CBT for functioning in schizophrenia is based on a cognitive model of functional outcome in schizophrenia that incorporates dysfunctional attitudes (eg, social disinterest, defeatist performance beliefs) as mediators between neurocognitive impairment and functional outcome. In this report, 18 clinical trials of CBT for schizophrenia that included measures of psychosocial functioning were reviewed, and two-thirds showed improvements in functioning in CBT. The cognitive model of functional outcome was also tested by examining the relationship between social disinterest attitudes and functional outcome in 79 people with schizophrenia randomized to either group cognitive-behavioral social skills training or a goal-focused supportive contact intervention. Consistent with the cognitive model, lower social disinterest attitudes at baseline and greater reduction in social disinterest during group therapy predicted better functional outcome at end of treatment for both groups. However, the groups did not differ significantly with regard to overall change in social disinterest attitudes during treatment, suggesting that nonspecific social interactions during group therapy can lead to changes in social disinterest, regardless of whether these attitudes are directly targeted by cognitive therapy interventions.     

The relationship of neuropsychological abilities to specific domains of functional capacity in older schizophrenia patients.

BACKGROUND: This study sought to determine the relative importance of cognitive measures in predicting various domains of everyday functional capacity in older outpatients with schizophrenia. METHODS: Ninety-three psychiatry outpatients with diagnoses of schizophrenia and schizoaffective disorders underwent a comprehensive neuropsychiatric evaluation, including neuropsychological testing and clinical ratings of psychopathology. Functional capacity was assessed with the Direct Assessment of Functional Status, a performance measure of basic and instrumental activities of daily living (ADLs/IADLs). RESULTS: Neuropsychological performance significantly predicted most ADLs/IADLs measured, except simple eating behaviors, time orientation, and grooming. Lower educational level and negative symptoms also were associated with worse functional capacity, whereas positive symptoms and depressed mood were not. Measures of cognitive functioning accounted for more variance in functional capacity than did psychiatric ratings of symptoms, and multiple regression analyses demonstrated that neuropsychological performance was predictive of functional capacity, over and above clinical symptoms. No specific cognitive domains were differentially predictive of specific domains of functional capacity. CONCLUSIONS: Neurocognitive abilities were more predictive of functional capacity than level of clinical symptoms; however, these abilities were not specific predictors of functioning. This is consistent with findings of relatively generalized, intercorrelated cognitive impairment in schizophrenia and multiply determined domains of everyday functioning.     

Test-performance after cognitive training in persons at risk mental state of schizophrenia and patients with schizophrenia

This exploratory study aims to examine the differential effects of a computer-based cognitive training in ‘prodromal’ patients (mean age 27.20 years, S.D. 5.31 years) compared with patients with full-blown schizophrenia (mean age 30.13 years, S.D. 7.77 years). Ten patients at risk for schizophrenia and 16 patients suffering from schizophrenia underwent a computerized cognitive training program (Cogpack). Cognitive functioning before and after a total of 10 training sessions was assessed by different tests controlling for memory, attention, and logical thinking. Prodromal patients turned out to be able to significantly improve their long-term memory functions and their attention after cognitive training with the Cogpack software package whereas in the group of patients with schizophrenia no improvement occurred (e.g. continuous performance test, identical pairs-subtest ‘shapes’: improvement from 0.73 to 0.88 in persons at risk of schizophrenia vs. no improvement in patients with schizophrenia (0.55 to 0.53). Cognitive training using Cogpack is helpful for the improvement of cognitive functioning in persons at risk of schizophrenia. Thus, the application of cognitive training should be provided as early as possible in the prodromal phases of schizophrenia in order to use the full rehabilitative potential of the patients. These results should be confirmed by further investigations including larger sample sizes.     

The association between verbal memory, processing speed, negative symptoms and functional capacity in schizophrenia

The aim of this paper is to explore the links among verbal memory, processing speed, negative symptoms, and functional capacity, using structural equation modeling techniques. Model A is a multiple regression model with cognitive and symptom variables as predictors and functional capacity as the latent outcome variable. Model B consists of three two mediator models that assess the ability of each variable to mediate the effect of the other variable on outcome conditional on the inclusion of the other mediator in the model. Ninety-eight community-dwelling patients with schizophrenia (mean age = 35.8 years, S.D. = 10.1) participated in the study. Results indicate that verbal memory, processing speed and negative symptoms significantly contributed to functional status. Verbal memory was at least partially mediated by processing speed in its effect on outcome, while the impact of processing speed on outcome was mediated by both verbal memory and negative symptoms. The influence of negative symptoms on functional capacity was partially mediated by processing speed. These findings enrich our understanding of the direct and indirect effects of these three interrelated variables and provide a basis for the development of intervention strategies.     

Depression and cognitive deficits in geriatric schizophrenia

Objective

Past reports have found patients with comorbid depression and schizophrenia spectrum disorders exhibit greater deficits in memory and attention compared to schizophrenia spectrum disorder patients without depressive symptoms. However, in contrast to younger schizophrenia patients, the few past studies using cognitive screens to examine the relationship between depression and cognition in inpatient geriatric schizophrenia have found that depressive symptomatology was associated with relatively enhanced cognitive performance. In the current study we examined the relationship between depressive symptoms and cognitive deficits in geriatric schizophrenia spectrum disorder patients (n = 71; mean age = 63.7) on an acute psychiatric inpatient service.

Method

Patients completed a battery of cognitive tests assessing memory, attention and global cognition. Symptom severity was assessed via the PANSS and Calgary Depression Scale for Schizophrenia.

Results

Results revealed that geriatric patients' depression severity predicted enhancement of their attentional and verbal memory performance. Patients' global cognitive functioning and adaptive functioning were not associated with their depression severity.

Conclusion

Contrary to patterns typically seen in younger patients and non-patient groups, increasing depression severity is associated with enhancement of memory and attention in geriatric schizophrenia spectrum disorder patients. Also, diverging from younger samples, depression severity was unassociated with patients adaptive and global cognitive functioning.     

Self-assessment of functional status in schizophrenia

With new treatments targeting features of schizophrenia associated with functional disability, there is a need to evaluate the validity of ratings of everyday outcomes. It is unknown whether patients can validly self-report on aspects of their functional status, which would be a potentially economical method for obtaining outcome data. In this study, 67 older schizophrenia outpatients provided self-ratings of everyday real-world functioning using the specific levels of functioning scale (SLOF). They were also administered assessments of neuropsychological performance, performance-based measures of functional capacity and social skills, clinical symptoms, and quality of life. Case managers, unaware of other ratings, also generated SLOF ratings. Based on discrepancy scores, participants were categorized as accurate raters (n = 24), underestimators (n = 16), or overestimators (n = 27) of their functional status as compared to case managers’ ratings. Patients’ self-rated functional status was correlated with their subjective quality of life, but remarkably unassociated with case manager ratings of functional status or their own performance on functional capacity or social skills measures. Case manager ratings, however, were highly correlated with performance on functional capacity and social skills measures. Patients who underestimated their real world performance had better cognitive skills and greater self-rated depression than those who overestimated. Accurate raters demonstrated greater social skills than both overestimators and underestimators, while overestimators were most cognitively and functionally impaired. Accurate ratings of everyday outcomes in schizophrenia may require systematic observation of real world outcomes or performance-based measures, as self-reports were inconsistent with objective information.     

Determinants of real-world functional performance in schizophrenia subjects: correlations with cognition, functional capacity, and symptoms

OBJECTIVE: Impairments in adaptive life skills are a major source of disability in patients with schizophrenia. The relationship between adaptive life skills in real-world settings and performance on neuropsychological tests may be complicated by other factors that interfere with deployment of skills. Assessment of the ability to perform life skills under optimal conditions (i.e., assessment of functional capacity) has been proposed as a means to clarify these relationships. METHOD: The authors examined cross-sectional data from a study of the course of neuropsychological and adaptive life skills of older (age 50-85) schizophrenia patients (N=78). Functional capacity was examined with a performance-based measure (UCSD Performance-Based Skills Assessment), and case managers rated real-world adaptive functions (i.e., interpersonal skills, work skills, and community activities). Neuropsychological performance was assessed with a comprehensive battery, while symptoms were assessed with patient self-report and clinical ratings. RESULTS: Confirmatory path analyses were used to evaluate the effects of neuropsychological performance, functional capacity, and symptoms on the various domains of real-world functioning. Neuropsychological performance predicted functional capacity, which predicted all three domains of real-world functioning. Depression predicted interpersonal and work skills, while negative symptoms affected interpersonal skills independently of other predictors. CONCLUSIONS: Real-world adaptive life skills are predicted by neuropsychological performance, symptoms, and functional capacity. Neuropsychological performance contributes little to the prediction of real-world performance after accounting for functional capacity. In some domains, negative and depressive symptoms influenced real-world performance while not relating to functional capacity or neuropsychological performance.     

Longitudinal study of symptoms and cognitive function in chronic schizophrenia

There is conflicting evidence of a relationship between changes in symptoms and cognitive functioning in schizophrenia. This study investigated longitudinal changes in psychopathology and cognitive functioning in chronic schizophrenia utilising three different dimensional models of symptomatology. Sixty-two patients diagnosed with DSM-IV schizophrenia or schizoaffective disorder were examined on two occasions over a period of 6 months for symptom improvement, measured by Positive and Negative Syndrome Scale (PANSS) [Kay et al., Schizophr. Bull. 13 (1987) 261]. Participants also completed a comprehensive battery of neuropsychological tasks designed to assess attention, verbal and non-verbal memory, psychomotor processing and executive/frontal functioning on both occasions. Twenty-five control subjects were assessed for comparison purposes. Severity of negative symptoms predicted poor neuropsychological performance on IQ, verbal fluency and memory measures at occasion one. However, using regression analyses, significant improvements in symptom ratings over time using two-, three- or five-dimensional models did not predict improvements in any aspect of cognitive functioning measured, except motor speed. The results do not suggest a causal relationship between the course of symptoms and neuropsychological functioning in chronic schizophrenia.     

Placebo-controlled trial of glycine added to clozapine in schizophrenia

OBJECTIVE: The purpose of this study was to evaluate the effects of high-dose oral glycine on positive and negative symptoms and cognitive function when added to clozapine in adults with schizophrenia. METHOD: The authors conducted a double-blind, placebo-controlled, parallel-group trial of 60 g/day of glycine added to clozapine for 8 weeks in 30 adults with schizophrenia. Clinical ratings were performed every 2 weeks. RESULTS: Twenty-seven patients completed the trial. Glycine augmentation of clozapine produced no statistically significant change in positive or negative symptoms or cognitive functioning. No subjects showed clinically significant worsening of clinical ratings. CONCLUSIONS: These data, combined with data from previous trials with D-cycloserine and glycine, suggest that agonists at the glycine site may be less effective when combined with clozapine than they are when combined with conventional antipsychotics.     

Negative symptoms and everyday functioning in schizophrenia: A cross-sectional study in a real world-setting

Negative symptoms have been suggested to have a greater impact on real-world functioning in schizophrenia than other symptoms. We aimed to examine the relationship of specific negative symptoms components (“expressive deficits” – DE – which include alogia and blunted affect, and “avolition” – AA – which includes amotivation, anhedonia, and asociality), with separate domains of real-world outcomes (the Personal and Social Performance Scale – PSP – and selected items of the Heinrichs Quality of Life Scale – QLS – that did not overlap with negative symptoms) and two functional milestones (recent employment and marriage). Regression analyses were performed to identify the determinants of QLS and PSP scores and of the two milestones, in 92 consecutive outpatients with stable schizophrenia. AA was the strongest predictor of QLS interpersonal relations and social network (IRSN), PSP total score and the first three PSP domains. The variance explained ranged from 36% for PSP self care to 54% for the PSP personal and social relationships. Moreover, higher scores in AA were significant predictors of the single status. DE does not appear to have an impact at real-world functional performance. Taken together, our analysis indicates a relatively specific set of relationships between the AA subdomain and aspects of real-world functioning in schizophrenia. These findings, if confirmed, could have important implications for research, diagnostics and treatment: in fact our results would suggest that AA and DE should be analyzed as separate and distinct domains to be rated and treated individually.     

Cognitive change processes in a group cognitive behavior therapy of depression

The present study attempted to examine the causal relationships among changes in automatic thoughts, dysfunctional attitudes, and depressive symptoms in a 12-week group cognitive behavior therapy (GCBT) program for depression. In all, 35 depressed patients attending the GCBT program were monitored with the Automatic Thoughts Questionnaire, Dysfunctional Attitudes Scale, and Beck Depression Inventory at the pre-treatment, 4th and 8th sessions, and post-treatment. The results were as follows: (1). GCBT reduces negative cognitions; (2). changes in automatic thoughts and dysfunctional attitudes lead to change in depressive symptoms; and (3). automatic thoughts play a mediating role between dysfunctional attitudes and depression. The findings taken as a whole support the Causal Cognition Model of depression.     

The relationship of early premorbid adjustment with negative symptoms and cognitive functions in first-episode schizophrenia: A prospective three-year follow-up study

Premorbid adjustment is an important prognostic factor of schizophrenia. The relationships between sub-components of premorbid adjustment and outcomes on symptoms and cognition in first-episode schizophrenia were under-studied. In the current study, we prospectively followed up 93 patients aged 18–55 years presenting with first-episode schizophrenia-spectrum disorder. Psychopathological and cognitive assessments were conducted at baseline, clinical stabilization, 12, 24 and 36 months. Premorbid adjustment was sub-divided into discrete functional domains, developmental stages and premorbid-course types based on ratings of the Premorbid Adjustment Scale (PAS). The study focused on early developmental stages to minimize contamination by prodromal symptoms. Results indicated that gender differences in premorbid functioning were primarily related to early-adolescence adjustment and academic domain. Social domain was more strongly related to negative symptoms, while academic domain was more consistently linked to cognitive outcome (Wisconsin Card Sorting test and verbal fluency). Patients with stable-poor premorbid course had more severe negative symptoms and cognitive impairment. In conclusion, in a Chinese cohort of first-episode schizophrenia-spectrum disorder, sub-components of early premorbid adjustment were shown to be differentially related to clinical and cognitive measures. The results highlighted the importance of applying a more refined delineation of premorbid functioning in studying illness outcome.     

Subjective and objective quality of life in schizophrenia

OBJECTIVE: Quality of life (QOL) is considered an important outcome in the treatment of schizophrenia, but the determinants of QOL are poorly understood in this population. Furthermore, previous studies have relied on combined measures of subjective QOL (usually defined as life satisfaction) and objective QOL (usually defined as participation in activities and relationships). We examined separately the clinical, functional, and cognitive predictors of subjective and objective QOL in outpatients with schizophrenia. We hypothesized that better subjective QOL would be associated with less severe negative and depressive symptoms, better objective QOL, and greater everyday functioning capacity, and that better objective QOL would be associated with less severe negative and depressive symptoms, better cognitive performance, and greater functional capacity. METHOD: Participants included 88 outpatients with schizophrenia or schizoaffective disorder who completed a comprehensive series of assessments, including measures of positive, negative, and depressive symptoms; performance-based functional skills; a neuropsychological battery; and an interview measure of subjective and objective QOL. RESULTS: In the context of multiple predictor variables, more severe depressive symptoms and better neuropsychological functioning were independent predictors of worse subjective QOL. More severe negative symptoms predicted worse objective QOL. Functional capacity variables were not associated with subjective or objective QOL. CONCLUSION: Treatments to improve QOL in schizophrenia should focus on negative symptoms and depressive symptoms.     

Independence and overlap among neurocognitive correlates of community functioning in schizophrenia

Existing literature on the neurocognitive correlates of community functioning in schizophrenia has not adequately focused on the relationships among the correlated variables. In a sample of 40 outpatients with schizophrenia and related disorders, we studied two sets of variables that we expected to be related to broad ratings of community functioning: (1) the Wechsler Adult Intelligence Scale-III (WAIS-III) index scores for verbal comprehension, perceptual organization, working memory, and processing speed; and (2) positive, negative, disorganized and affective symptom variables. Of the WAIS-III index scores, working memory and processing speed entered a stepwise regression, together accounting for substantial variance in functional ratings (R(2)=0.37). However, only processing speed remained significantly associated with community functioning after controlling for the other indexes. In relation to community functioning, the remaining indexes appeared to be overlapping markers of general cognitive ability, rather than specific measures of discrete cognitive domains. Addition of positive and negative symptom variables in a further analysis greatly increased the explained functional variance (R(2)=0.65). Processing speed overlapped substantially with negative symptoms in predicting functioning, while the other WAIS-III indexes were independent of symptomatology. Results illustrate the importance of (1) knowing which neurocognitive variables have specific relationships to community functioning and which reflect the influence of more general cognitive ability in daily life, and (2) appreciating areas of overlap and independence among classes of correlates of functioning, such as neurocognitive and symptom variables. This improved understanding has implications for predictive models of community functioning, for cognitive rehabilitation and deficit compensation strategies, and for assessment practice.     

Diminished humour perception in schizophrenia: Relationship to social and cognitive functioning

This study attempted to confirm that humour recognition deficits previously found in schizophrenia are specific to the condition and not attributable to other parameters such as depression or anxiety. Secondarily, we explored any possible cognitive or social functioning correlates to humour recognition deficits. A total of 60 participants (20 outpatients with schizophrenia, 20 psychiatric control participants and 20 control participants) underwent a 64-question humour task in addition to a battery of standard cognitive tests and Social Functioning Scales. In order to compare the three groups of participants, we conducted an analysis of variance (ANOVA) and post-hoc t-tests on neuropsychological measures, social functioning measures, and the primary outcome, humour recognition. The schizophrenia group showed significant and substantial deficits in humour recognition compared to the healthy control group, t(38) = 5.1, P < 0.001, ES = −1.55 and the psychiatric control group, t(38) = 3.6, P = 0.001. In the schizophrenia group, humour recognition correlated positively with general intellectual functioning (NART) r = .45, P = 0.04, social reasoning (WAIS-III Comprehension) r = .54, P = 0.01, executive functioning (WCST-CC) r = .69, P = 0.001 and social adjustment ratings (SASS scores), r = .54, P = 0.02. These findings support the assertion that humour recognition deficits in schizophrenia are specific to the condition and not attributable to other factors such as depression or anxiety. Furthermore, humour recognition deficits in schizophrenia may perhaps be preferentially associated with deficiencies in set shifting and semantic cognition.     

The convergence of neuropsychological testing and clinical ratings of cognitive impairment in patients with schizophrenia.

This study examined the relationship between clinical rating of cognitive symptoms and performance on neuropsychological tests in acute and chronic samples of patients with schizophrenia. Two separate studies examined patients who varied widely in their lifetime functional outcome, including 263 elderly poor-outcome inpatients and 20 acutely admitted patients. In the first study, six cognitive performance measures were collected, and in the second study, five different measures were collected. Correlations with different symptom models of cognitive and negative symptoms were examined. In both samples, cognitive symptoms were never more highly correlated with cognitive test performance than with negative symptoms. When cognitive and negative symptom ratings were combined, they never accounted for as much as half of the variance in performance on the cognitive tests in both samples. These data suggest that clinical assessment of symptoms is not a viable alternative to neuropsychological testing to obtain information about cognitive functioning in schizophrenia. These results may also be specific to the clinical rating scale used, the Positive and Negative Syndrome Scale (PANSS).