Recovery from psychosis in schizophrenia and schizoaffective disorder: symptoms and neurocognitive rate-limiters for the development of social behavior skills

Transcranial direct current stimulation of the occipital lobes with adjunct lithium attenuates the progression of cognitive impairment in patients with first episode schizophrenia

BACKGROUND

There is no standard effective treatment for schizophrenia-associated cognitive impairment. Efforts to use non-invasive brain stimulation for this purpose have been focused mostly on the frontal cortex, with little attention being given to the occipital lobe.

MATERIALS AND METHODS

We compared the effects of nine intervention strategies on cognitive performance in psychometric measures and brain connectivity measured obtained from functional magnetic resonance imaging analyses. The strategies consisted of transcranial direct current stimulation (t-DCS) or repetitive transcranial magnetic stimulation (r-TMS) of the frontal lobe or of the occipital alone or with adjunct lithium, or lithium monotherapy. We measured global functional connectivity density (gFCD) voxel-wise.

RESULTS

Although all nine patient groups showed significant improvements in global disability scores (GDSs) following the intervention period (vs. before), the greatest improvement in GDS was observed for the group that received occipital lobe-targeted t-DCS with adjunct lithium therapy. tDCS of the occipital lobe improved gFCD throughout the brain, including in the frontal lobes, whereas stimulation of the frontal lobes had less far-reaching benefits on gFCD in the brain. Adverse secondary effects (ASEs) such as heading, dizziness, and nausea, were commonly experienced by patients treated with t-DCS and r-TMS, with or without lithium, whereas ASEs were rare with lithium alone.

CONCLUSION

The most effective treatment strategy for impacting cognitive impairment and brain communication was t-DCS stimulation of the occipital lobe with adjunct lithium therapy, though patients often experienced headache with dizziness and nausea after treatment sessions.

Mechanisms underlying dorsolateral prefrontal cortex contributions to cognitive dysfunction in schizophrenia

Kraepelin, in his early descriptions of schizophrenia (SZ), characterized the illness as having "an orchestra without a conductor." Kraepelin further speculated that this "conductor" was situated in the frontal lobes. Findings from multiple studies over the following decades have clearly implicated pathology of the dorsolateral prefrontal cortex (DLPFC) as playing a central role in the pathophysiology of SZ, particularly with regard to key cognitive features such as deficits in working memory and cognitive control. Following an overview of the cognitive mechanisms associated with DLPFC function and how they are altered in SZ, we review evidence from an array of neuroscientific approaches addressing how these cognitive impairments may reflect the underlying pathophysiology of the illness. Specifically, we present evidence suggesting that alterations of the DLPFC in SZ are evident across a range of spatial and temporal resolutions: from its cellular and molecular architecture, to its gross structural and functional integrity, and from millisecond to longer timescales. We then present an integrative model based upon how microscale changes in neuronal signaling in the DLPFC can influence synchronized patterns of neural activity to produce macrocircuit-level alterations in DLPFC activation that ultimately influence cognition and behavior. We conclude with a discussion of initial efforts aimed at targeting DLPFC function in SZ, the clinical implications of those efforts, and potential avenues for future development.

The link between formal thought disorder and social functioning in schizophrenia: A meta-analysis

BACKGROUND

Formal thought disorder (FTD) and social functioning impairments are core symptoms of schizophrenia. Although both have been observed for over a century, the strength of the relationship between FTD and social functioning remains unclear. Furthermore, a variety of methodological approaches have been used to assess these constructs-which may contribute to inconsistency in reported associations. This meta-analysis aimed to: (a) systematically test the relationship between FTD and social functioning and (b) determine if the methodology used to assess FTD and/or social functioning moderates this relationship.

METHODS

Following Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines, a targeted literature search was conducted on studies examining the relationship between FTD and social functioning. Correlations were extracted and used to calculate weighted mean effect sizes using a random effects model.

RESULTS

A total of 1,478 participants across 13 unique studies were included in this meta-analysis. A small-medium inverse association (r = -0.23, p < 0.001) was observed between FTD and social functioning. Although heterogeneity analyses produced a significant Q-statistic (Q = 52.77, p = <0.001), the relationship between FTD and social functioning was not moderated by methodology, study quality, demographic variables, or clinical factors.

CONCLUSIONS

Findings illustrate a negative association between FTD and social functioning. Despite differences in the methodological approach used and type of information assessed, measurement type and clinical factors did not moderate the relationship between FTD and social functioning. Future studies should explore whether other variables, such as cognitive processes (e.g., social cognition), may account for variability in associations between these constructs.

Negative and disorganized symptoms mediate the relationship between verbal learning and global functioning in adolescents with early-onset psychosis

Neurocognitive deficits are associated with impaired global functioning and psychotic symptoms. However, whether symptoms can mediate the relationship between neurocognition and global functioning in adolescent psychosis is unclear. Here, we investigated if symptoms assessed with the Positive And Negative Syndrome Scale (PANSS), mediated the relationship between neurocognitive performance and global functioning in adolescents with non-affective early-onset psychotic disorders (EOP). Sixty-one adolescent EOP patients (age 12-18 years) from 2 Norwegian clinical cohorts were included. Linear regression models were applied to investigate associations between neurocognitive domains from the MATRICS Consensus Cognitive Battery (MCCB) and global functioning. PANSS symptoms were analyzed using the Wallwork/Fortgang five-factor model. Using the INDIRECT macro for SPSS, mediation effects were tested using bootstrapping with 95% bias corrected confidence intervals. Verbal learning was positively associated with global functioning (P < 0.001) and negatively associated with the disorganized symptom factor (P = 0.002), controlling for age, sex and cohort. Testing of indirect effects, controlling for age, sex and cohort, showed that the Negative (point estimate = 1.56, 95% CI 0.22, 3.47) and Disorganized (point estimate = 1.24, 95% CI 0.05, 3.69) symptom factors significantly mediated the relationship between verbal learning and global functioning. We found that verbal learning, negative and disorganized symptoms influenced global functioning in adolescents with EOP, while reality-distorted positive symptoms did not. These results suggest that assessing these domains in EOP is helpful for planning treatment and rehabilitation programs focusing on functional outcome.

Childhood maltreatment and treatment outcome in psychotic disorders: a systematic review and meta-analysis

OBJECTIVE

Childhood maltreatment (CM) plays an important role in the aetiology and course of psychotic disorders and is associated with characteristics that could be relevant for treatment. We aimed to conduct a systematic review and meta-analysis on the association between CM and treatment outcome in psychotic disorders.

METHODS

Treatment outcome was defined as change in psychotic symptoms or in social or occupational functioning between first and last reported measurement in the course of a pharmacological and/or psychological treatment.

RESULTS

Twelve treatment results from seven studies (636 patients, average treatment duration: 59.2 weeks) were included. CM was related to poorer treatment outcomes in psychotic disorders (OR = 1.51, 95% CI = [1.08, 2.10]). There is evidence that this association might increase with illness duration and increasing age and might be stronger in schizophrenia samples.

CONCLUSIONS

Childhood maltreatment is highly understudied with regard to treatment outcome in psychotic disorders. The need for more studies is emphasized by the fact that this meta-analysis reveals evidence for a poorer treatment response in patients with CM. If this association is confirmed, the identification of patients with CM and the consideration of associated clinical and biological conditions could contribute to improve treatment outcome in psychotic disorders.

Longitudinal trajectory of early functional recovery in patients with first episode psychosis

BACKGROUND

There is a large variability in the recovery trajectory and outcome of first episode of psychosis [FEP] patients. To date, individuals' outcome trajectories at early stage of illness and potential risk factors associated with a poor outcome trajectory are largely unknown. This study aims to apply three separate predictors (positive symptoms, negative symptoms, and soft neurological signs) to identify homogeneous function outcome trajectories in patients with FEP using objective data-driven methods, and to explore the potential risk /protective factors associated with each trajectory.

METHODS

A total of 369 first episode patients (93% antipsychotic naive) were included in the baseline assessments and followed-up at 4-8 weeks, 6 months, and 1 year. K means cluster modeling for longitudinal data (kml3d) was used to identify distinct, homogeneous clusters of functional outcome trajectories. Patients with at least 3 assessments were included in the trajectory analyses (N = 129). The Scale for the Assessment of Negative Symptoms (SANS), Scale for the Assessment of Positive Symptoms (SAPS), and Neurological examination abnormalities (NEA) were used as predictors against Global Assessment of Functioning Scale (GAF).

RESULTS

In each of the three predictor models, four distinct functional outcome trajectories emerged: "Poor", "Intermediate", High" and "Catch-up". Individuals with male gender; ethnic minority status; low premorbid adjustment; low executive function/IQ, low SES, personality disorder, substance use history may be risk factors for poor recovery.

CONCLUSIONS

Functioning recovery in individuals with FEP is heterogeneous, although distinct recovery profiles are apparent. Data-driven trajectory analysis can facilitate better characterization of individual longitudinal patterns of functioning recovery.

Association between symptom control and functional improvement in patients with acute schizophrenia: A post hoc analysis of an open-label, single-arm, multi-center study of paliperidone-extended release formulation

Both symptom control and functional improvement are important goals in schizophrenia treatment. A post hoc analysis of an 8-week, open-label, single-arm, multi-center study of paliperidone-extended release formulation was conducted to evaluate the correlation between personal/social functioning and symptom control in the acute phase, and to identify factors associated with psychosocial functioning, in patients with acute schizophrenia. Of 608 enrolled patients, 602 (99%) were included in the full analysis set. Correlation and regression analyses were applied to identify the association of Personal and Social Performance (PSP) total scores with Positive and Negative Syndrome Scale (PANSS) total scores and other factors. A significant negative correlation was observed between PSP and PANSS at all visits (week 1: r = -0.55; week 2: r = -0.79, p < 0.0001). Patients with PSP score improvement (≥10 point) showed a higher possibility of symptom improvement (PANSS reduction ≥30%). Duration of illness, PANSS Marder factors, and satisfaction with prior treatment, sleep quality, and daytime drowsiness influenced change in PSP total score at endpoint. These results suggest symptom outcome as an important factor to predict functional improvement in acute schizophrenia.

Disorganization and real-world functioning in schizophrenia: Results from the multicenter study of the Italian Network for Research on Psychoses

BACKGROUND

A general consensus has not yet been reached regarding the role of disorganization symptoms in real-world functioning in schizophrenia.

METHODS

We used structural equations modeling (SEM) to analyze the direct and indirect associations between disorganization and real-world functioning assessed through the Specific Levels of Functioning Scale (SLOF) in 880 subjects with schizophrenia.

RESULTS

We found that: 1) conceptual disorganization was directly and strongly connected with SLOF daily activities; difficulty in abstract thinking was associated with moderate strength to all SLOF domains, and poor attention was connected with SLOF work skills; 2) grandiosity was only related with poor work skills, and delusions were associated with poor functioning in all SLOF domains; interpersonal relationships were weakly indirectly influenced by hallucinatory behavior, delusions and unusual thought contents through the mediation of social cognition (SC); 3) among the negative symptoms, avolition had only direct links with SLOF work skills and SLOF activities; anhedonia had direct links with SLOF work skills and SLOF interpersonal and indirect link with SLOF work skills through functional capacity (FC); asociality with SLOF interpersonal; blunted affect had direct links with SLOF activities and indirect links with SLOF interpersonal relationships mediated by SC. Lastly, alogia had only indirect links mediated by SC, FC, and neurocognition (NC).

CONCLUSIONS

Overall conceptual disorganization is the symptom that contributed more (both directly and indirectly) to the activities of community living in real-world. Thus, it should be considered as a treatment target in intervention programs for patients with schizophrenia.

The role of cognitive functioning in the relationship between childhood trauma and a mixed phenotype of affective-anxious-psychotic symptoms in psychotic disorders

Cognitive impairments in patients with psychotic disorder have been associated with poor functioning and increased symptom severity. Furthermore, childhood trauma (CT) exposure has been associated with worse cognitive functioning as well as co-occurrence of affective-anxious-psychosis symptoms or a 'mixed phenotype of psychopathology' (MP), which in turn is associated with greater symptom severity, and poor functioning. This study aims to evaluate if cognition could be associated with CT/MP. 532 patients with non-affective psychotic patients were assessed on CT, symptom profile, cognition, functioning, and symptom severity at baseline and 3 and 6-year follow-up. Four subgroups were made according to trauma exposure (CT- or CT+) and presence of a mixed phenotype (MP- or MP+): CT-/MP (n=272), CT-/MP+ (n=157), CT+/MP- (n=49), and CT+/MP+ (n=54). Mixed-effects multilevel regression, linear regression, and Tobit analyses were performed. Patients with both CT and MP showed lower verbal learning and memory than CT-/MP+ individuals (p<0.001). No other significant differences were found among the 4 subgroups. No cognitive decline was found at follow-up, neither in the CT+/MP- nor in CT-/MP- group. Lower cognition was not associated with increased symptom severity or poor functioning at follow-up, neither in the CT+/MP- nor in CT-/MP- group. Although cognitive impairments and CT may be related to clinical or functional features of psychotic disorder, and cognitive functioning could be affected by CT exposure, cognition does not discriminate subgroups of patients stratified by CT exposure and MP.

Defining functioning levels in patients with schizophrenia: A combination of a novel clustering method and brain SPECT analysis

This study aims to define functioning levels of patients with schizophrenia by using a method of interpretable clustering based on a specific functioning scale, the Functional Remission Of General Schizophrenia (FROGS) scale, and to test their validity regarding clinical and neuroimaging characterization. In this observational study, patients with schizophrenia have been classified using a hierarchical top-down method called clustering using unsupervised binary trees (CUBT). Socio-demographic, clinical, and neuroimaging SPECT perfusion data were compared between the different clusters to ensure their clinical relevance. A total of 242 patients were analyzed. A four-group functioning level structure has been identified: 54 are classified as "minimal", 81 as "low", 64 as "moderate", and 43 as "high". The clustering shows satisfactory statistical properties, including reproducibility and discriminancy. The 4 clusters consistently differentiate patients. "High" functioning level patients reported significantly the lowest scores on the PANSS and the CDSS, and the highest scores on the GAF, the MARS and S-QoL 18. Functioning levels were significantly associated with cerebral perfusion of two relevant areas: the left inferior parietal cortex and the anterior cingulate. Our study provides relevant functioning levels in schizophrenia, and may enhance the use of functioning scale.

Exploring functioning in schizophrenia: Predictors of functional capacity and real-world behaviour

Impairment in daily functioning still represents a major treatment issue in schizophrenia and a more in-depth knowledge of underlying constructs is crucial for interventions to translate into better outcomes. This study aims to model factors influencing both functional capacity and real-life behaviour in a sample of outpatients with chronic schizophrenia, through a comprehensive assessment including evaluations of psychopathology, cognitive and social cognitive abilities, premorbid adjustment, family environment and early childhood experiences. No significant correlation was observed between functional capacity and real-life behaviour. Functional capacity was significantly predicted by IQ, while real-life behaviour was significantly predicted by empathy, affect recognition and symptoms. Functional capacity seems mainly related to neurocognition, whereas real-life behaviour appears more complex, requiring the integration of different factors including symptoms, with a major role of empathy. Results thus support a divergence between the two constructs of functioning and their underlying components and highlight the need to target both dimensions through individualized sequential rehabilitation programs in order to optimize functional outcome.

Association between social contact frequency and negative symptoms, psychosocial functioning and quality of life in patients with schizophrenia

The lack of social contacts may be an important element in the presumed vicious circle aggravating, or at least stabilising negative symptoms in patients with schizophrenia. A European 2-year cohort study collected negative symptom scores, psychosocial functioning scores, objective social contact frequency scores and quality of life scores every 6 months. Bivariate analyses, correlation analyses, multivariate regressions and random effects regressions were conducted to describe relations between social contact and outcomes of interest and to gain a better understanding of this relation over time. Using data from 1208 patients with schizophrenia, a link between social contact frequency and negative symptom scores, functioning and quality of life at baseline was established. Regression models confirmed the significant association between social contact and negative symptoms as well as psychosocial functioning. This study aimed at demonstrating the importance of social contact for deficient behavioural aspects of schizophrenia.

Conceptual disorganization weakens links in cognitive pathways: Disentangling neurocognition, social cognition, and metacognition in schizophrenia

Disentangling links between neurocognition, social cognition, and metacognition offers the potential to improve interventions for these cognitive processes. Disorganized symptoms have shown promise for explaining the limiting relationship that neurocognition holds with both social cognition and metacognition. In this study, primary aims included: 1) testing whether conceptual disorganization, a specific disorganized symptom, moderated relationships between cognitive processes, and 2) examining the level of conceptual disorganization necessary for links between cognitive processes to break down. To accomplish these aims, comprehensive assessments of conceptual disorganization, neurocognition, social cognition, and metacognition were administered to 67 people with schizophrenia-spectrum disorders. We found that conceptual disorganization significantly moderated the relationship between neurocognition and metacognition, with links between cognitive processes weakening when conceptual disorganization is present even at minimal levels of severity. There was no evidence that conceptual disorganization-or any other specific disorganized symptom-drove the limiting relationship of neurocognition on social cognition. Based on our findings, conceptual disorganization appears to be a critical piece of the puzzle when disentangling the relationship between neurocognition and metacognition. Roles of specific disorganized symptoms in the neurocognition - social cognition relationship were less clear. Findings from this study suggest that disorganized symptoms are an important treatment consideration when aiming to improve cognitive impairments.

Neurocognition as a predictor of outcome in schizophrenia in the Northern Finland Birth Cohort 1966

The purpose of this study was to study neurocognitive performance as a predictor of outcomes in midlife schizophrenia. There is a lack of studies with unselected samples and a long follow-up. The study is based on the prospective, unselected population-based Northern Finland Birth Cohort 1966. The study includes 43 individuals with schizophrenia and 73 controls, whose neurocognitive performance was assessed twice, at 34 and 43 years. At both time points we used identical neurocognitive tests to assess verbal and visual memory and executive functions. Our main aim was to analyse neurocognitive performance at 34 years as a predictor of clinical, vocational and global outcomes at 43 years. Additionally, the analysis addressed cross-sectional associations between cognitive performance and clinical, vocational and global measures at 43 years. The assessment of outcomes was performed in the schizophrenia group only. In the longitudinal analysis poorer visual memory predicted poorer vocational outcome and poorer long-term verbal memory predicted poorer global outcome. In the cross-sectional analysis poorer visual memory and lower composite score of neurocognition were associated with poorer global outcome. No individual neurocognitive test or the composite score of these predicted remission. These data indicate that neurocognition, especially memory function, is an important determinant of long-term functional outcome in midlife schizophrenia.

Glutamatergic metabolite correlations with neuropsychological tests in first episode schizophrenia

Increased glutamatergic metabolites have been found in first episode schizophrenia. Although abnormal neuropsychological functioning has been demonstrated to be a core feature of schizophrenia, no studies have examined glutamatergic metabolites and neuropsychological function in drug-naïve patients. The present study addressed whether higher levels of glutamatergic metabolites would be associated with poorer neuropsychological performance and social functioning in first episode patients. Glutamatergic concentration estimates were obtained from the left anterior cingulate cortex (ACC) and thalamus at baseline and 10 months after treatment in 16 patients with psychosis using 4.0 T (1)H magnetic resonance spectroscopy. A neuropsychological test battery was administered at baseline and 1 year. In the ACC, baseline glutamine was associated with performance on the Paced Auditory Serial Addition Task (PASAT). Glutamate at 10 months was associated with Wisconsin Card Sorting Test (WCST) errors and Trail-Making Test-B duration. Glutamine at 10 months was positively associated with WCST errors and negatively associated with WCST categories completed. In the thalamus, baseline glutamine was negatively associated with performance on the PASAT. Thalamic glutamate at baseline showed a trend towards a negative association with social functioning at 5 years. Glutamatergic metabolites were associated with neuropsychological test deficits and impaired social functioning at 5-year follow-up in patients with first episode psychosis, findings suggestive of an association between glutamatergic alterations on neurotoxicity early in the course of schizophrenia.

The effects of aging on insight into illness in schizophrenia: a review

OBJECTIVES

Impaired insight into illness is a prevalent feature of schizophrenia, which negatively influences treatment adherence and clinical outcomes. Little is known about the effects of aging on insight impairment. We aimed to review the available research literature on the effects of aging on insight into illness in schizophrenia, in relation to positive, negative, and cognitive symptoms. Ultimately, we propose a trajectory of insight in schizophrenia across the lifespan.

METHOD

A systematic Medline® literature search was conducted, searching for English language studies describing the relationship of insight into illness in schizophrenia with aging.

RESULTS

We identified 62 studies. Insight impairment is associated with illness severity, premorbid intellectual function (i.e. IQ), executive function, and memory. Insight impairment improves modestly during midlife, worsening again in late life. It tends to fluctuate with each episode of psychosis, likely in relation to worsening positive symptoms that improve with antipsychotic treatment. The relationship between insight impairment and cognitive dysfunction appears to attenuate with age, while the relationship with lower premorbid intellectual function is preserved. The association between impaired insight and negative symptoms is unclear.

CONCLUSIONS

The available literature suggests that the course of insight impairment follows a U-shaped curve, where insight impairment is severe during the first episode of psychosis, modestly improves over midlife, and declines again in late life. Future studies are required to investigate the trajectory of insight into illness and its core domains across the lifespan from prodromal phase to late life.

Necessary, but not sufficient: links between neurocognition, social cognition, and metacognition in schizophrenia are moderated by disorganized symptoms

Intact neurocognition has been posited as a necessary, but not sufficient prerequisite for efficient social cognition and metacognition in schizophrenia. Disorganized symptoms likely play a prominent role in these cognitive processes, given the detrimental effects of disorganization on one's ability to synthesize discrete information into an organized whole. However, the relationship between disorganized symptoms and cognitive processes remains unclear. In this study, we examined whether disorganized symptoms: 1) exhibited stronger inverse relationships with cognitive processes than other symptoms, and 2) moderated links between neurocognition and a) social cognition, and b) metacognition. Trained raters assessed psychotic symptoms, neurocognition, social cognition, and metacognition in patients with schizophrenia from a Midwestern VA Medical Center (n=68) using validated, clinician-rated instruments. We observed significantly greater inverse associations with cognitive processes for disorganized compared to reality distortion symptoms; inverse associations with neurocognition and social cognition were significantly greater for disorganized than negative symptoms. Our hypotheses that disorganized symptoms would moderate relationships between neurocognition and a) social cognition, and b) metacognition were also supported. These findings highlight the importance of disorganized symptoms in elucidating links between neurocognition and social cognitive and metacognitive abilities. Future work should assess whether similar findings occur across the schizophrenia-spectrum, and investigate if targeting disorganization can ameliorate social cognitive and metacognitive impairments in schizophrenia.

The longitudinal association between social functioning and theory of mind in first-episode psychosis

INTRODUCTION

There is some cross-sectional evidence that theory of mind ability is associated with social functioning in those with psychosis but the direction of this relationship is unknown. This study investigates the longitudinal association between both theory of mind and psychotic symptoms and social functioning outcome in first-episode psychosis.

METHODS

Fifty-four people with first-episode psychosis were followed up at 6 and 12 months. Random effects regression models were used to estimate the stability of theory of mind over time and the association between baseline theory of mind and psychotic symptoms and social functioning outcome.

RESULTS

Neither baseline theory of mind ability (regression coefficients: Hinting test 1.07 95% CI -0.74, 2.88; Visual Cartoon test -2.91 95% CI -7.32, 1.51) nor baseline symptoms (regression coefficients: positive symptoms -0.04 95% CI -1.24, 1.16; selected negative symptoms -0.15 95% CI -2.63, 2.32) were associated with social functioning outcome. There was evidence that theory of mind ability was stable over time, (regression coefficients: Hinting test 5.92 95% CI -6.66, 8.92; Visual Cartoon test score 0.13 95% CI -0.17, 0.44).

CONCLUSIONS

Neither baseline theory of mind ability nor psychotic symptoms are associated with social functioning outcome. Further longitudinal work is needed to understand the origin of social functioning deficits in psychosis.

Investigation of the role of the jumping-to-conclusions bias for short-term functional outcome in schizophrenia

Symptom severity and neuropsychological deficits negatively influence functional outcomes in patients with schizophrenia. Recent research implicates specific types of biased thinking styles (e.g. jumping-to-conclusions) in the pathogenesis of schizophrenia. This is the first study to test the impact of jumping-to-conclusions on functional outcome in schizophrenia. The aim of the study was to investigate the association of psychopathology, neuropsychology and JTC with subjective quality of life, vocational outcome and housing status in schizophrenia. Analyses were carried out both cross-sectionally at baseline, and longitudinally over the course of symptomatic improvement in the immediate aftermath of a psychotic exacerbation. Seventy-nine patients with schizophrenia were included in the study. Data concerning the variables of interest were collected at baseline, after one month, and after six months. Positive symptomatology was the most significant predictor of subjective and vocational outcome and changes across time. Verbal memory deficits were associated with functional status cross-sectionally, whereas general cognitive capacity significantly predicted functional changes over time. Improvement of the jumping-to-conclusions bias positively affected vocational outcome. Though limited, the observed effect of this bias on real-world functioning highlights the possible usefulness of interventions aimed at improving (meta)cognitive deficits in schizophrenia.

Correlation between the Personal and Social Performance scale (PSP) and the Positive and Negative Syndrome Scale (PANSS) in a Greek sample of patients with schizophrenia

BACKGROUND

Psychosocial dysfunction is one of schizophrenia's core features, often leading to a deprecation of independent living and significant failure to maintain a competent quality of life. Cognitive and occupational performance as well as psychosocial functioning is moreover recognized as determinants of treatment response. Therefore, the elaboration of measures regarding social performance besides scales that assess psychopathology is essential. The Personal and Social Performance (PSP) scale has been found to be as much valid as reliable for assessing social functioning in the acute and stable stage of schizophrenia. The aim of this study was to estimate the correlation between the PSP and Positive and Negative Syndrome Scale (PANSS) (convergent validity) in patients with schizophrenia during routine clinical practice.

METHODS

A longitudinal study with a six-month follow-up is presented. Correlation between the PSP scale and the Positive and Negative Syndrome Scale (PANSS) was conducted in a Greek sample of 2010 patients with schizophrenia in outpatient setting in two successive visits. PANSS and PSP scales were used for the assessment of psychopathological symptoms and social and personal functioning.

RESULTS

The PSP subscales scores were well correlated with each other with Spearman correlation coefficients (r) ranging from 0.56 to 0.76 on both visits in three out of the four main areas, whereas in the category of "disturbing and aggressive behavior" the correlations were lower but still significant. Furthermore, total PSP score showed high association to PANSS total score in the first (r = -0.59) as well as in the second visit (r = -0.50). Regression analysis showed that one point decrease of PANSS's total score is associated with a 0.42 points increase on the PSP scale. PSP and PANSS scales exhibited high convergent validity.

CONCLUSIONS

The PSP could provide additional valuable information in the assessment of schizophrenia related social functioning and treatment response.

A Longitudinal Examination of the Moderating Effects of Symptoms on the Relationship between Functional Competence and Real World Functional Performance in Schizophrenia

BACKGROUND

Many individuals with schizophrenia experience remission of prominent positive symptoms but continue to experience impairments in real world functioning. Residual negative and depressive symptoms may have a direct impact on functioning and impair patients' ability to use the cognitive and functional skills that they possess (competence) in the real world (functional performance).

METHODS

136 individuals (100 men, 36 women) with schizophrenia were classified as having primarily positive symptoms, primarily negative symptoms, primarily depressive symptoms, or undifferentiated symptom profiles. Performance based measures of cognition and adaptive and interpersonal functional competence were used, along with ratings of real world behavior by high contact clinicians. Assessments were performed at baseline and at an 18-month follow-up.

RESULTS

The relationships between neurocognition and capacity / performance were not moderated by symptom group ps > .091; neurocognition predicted capacity and performance for all groups ps < .001. The relationship between adaptive competence and adaptive performance was moderated by symptom group, ps < .01, such that baseline competence only predicted future performance ratings for participants with primarily positive or undifferentiated symptoms, and not for individuals with primarily negative or depressive symptoms. This same moderation effect was found on the relationship between interpersonal competence and interpersonal performance, ps < .002.

CONCLUSIONS

Residual negative and depressive symptoms are distinct constructs that impede the use of functional skills in the real world. Depressive symptoms are often overlooked in schizophrenia but appear to be an important factor that limits the use of functional ability in real world environments.

Neurocognition, functional capacity, and functional outcomes: the cost of inexperience

BACKGROUND

Neurocognitive impairments are the strongest predictor of functional deficits in schizophrenia, but adaptive (i.e., functional) capacity, typically measured with performance-based assessments, yields an objective index of current abilities, whereas real-world functional performance relies on observations of community activity. However, limited experiences in the community may limit the acquisition, retention, or expression of these skills.

METHODS

We examined the frequency of engagement in behaviors that are assessed in the current "gold standard" in person functional capacity assessment. The UCSD Performance-Based Skills Assessment (i.e., UPSA) examines skills associated with recreational engagement, handling money, scheduling appointments, and navigating public transportation. We used neurocognition, experience, and UPSA performance as predictors of the relationships among cognition and real-world functioning variables.

RESULTS

Neurocognition was a significant correlate of UPSA scores regardless of whether it was forced into the model before or after prior experience, whereas experience was only a significant predictor of UPSA scores when entered before neurocognition. Further, functional capacity, neurocognition, and experience were significant predictors of real-world outcomes and experience remained a significant predictor regardless of the order it was entered into the model.

CONCLUSIONS

The amount of current experience with functional tasks is not a rate-limiter of the relationships between neurocognition and functional capacity but does account for some previously unexplained variance in the functional capacity-everyday functioning relationship. These findings underscore the importance of neurocognitive deficits as they relate to functional capacity in schizophrenia, and suggest an incremental functional cost of limited experience with independent living.

Cognition, function, and disability in patients with schizophrenia: a review of longitudinal studies

This paper aims to review longitudinal studies assessing the impact of cognition on function in patients with schizophrenia. PubMed and Scholars Portal were searched using search terms related to schizophrenia, cognition, function, and longitudinal studies. Some functional abilities have been studied more than others. Some studies suggest that the impact of cognition on function depends on the severity of baseline cognitive deficits. Other studies suggest that the impact of cognition on function depend on what phase of the illness the patient is in or what stage in that particular function the patient is involved in. Finally, few studies assessed interactions between cognition and other aspects of schizophrenia in predicting function, such as functional capacity, insight, motivation, and negative symptoms. More longitudinal and comprehensive studies are needed. A focus on community living is of high public significance as patients with schizophrenia continue to grow old. Future studies should also focus on the longitudinal interactions between cognition and other dimensions of schizophrenia as well as on the biological factors that underlie these interactions.

Prediction of functional outcome in individuals at clinical high risk for psychosis

IMPORTANCE

A major public health concern associated with schizophrenia and psychotic disorders is the long-term disability that involves impaired cognition, lack of social support, and an inability to function independently in the community. A critical goal of early detection and intervention studies in psychosis is therefore to understand the factors leading to this often profound impairment.

OBJECTIVE

To develop a predictive model of functional (social and role) outcome in a clinical high-risk sample for psychosis.

DESIGN

Prospective, naturalistic, longitudinal 3- to 5-year follow-up study.

SETTING

The Recognition and Prevention Program in New York, a research clinic located in the Zucker Hillside Hospital in New York.

PARTICIPANTS

One hundred one treatment-seeking patients at clinical high risk for psychosis. Ninety-two (91%) were followed up prospectively for a mean (SD) of 3 (1.6) years.

INTERVENTION

Neurocognitive and clinical assessment.

MAIN OUTCOMES AND MEASURES

The primary outcome variables were social and role functioning at the last follow-up visit.

RESULTS

Poor social outcome was predicted by reduced processing speed (odds ratio [OR], 1.38; 95% CI, 1.050-1.823; P = .02), impaired social functioning at baseline (OR, 1.85; 95% CI, 1.258-2.732; P = .002), and total disorganized symptoms (OR, 5.06; 95% CI, 1.548-16.527; P = .007). Reduced performance on tests for verbal memory (OR, 1.74; 95% CI, 1.169-2.594; P = .006), role functioning at baseline (OR, 1.34; 95% CI, 1.053-1.711; P = .02), and motor disturbances (OR, 1.77; 95% CI, 1.060-2.969; P = .03) predicted role outcome. The areas under the curve for the social and role prediction models were 0.824 (95% CI, 0.736-0.913; P < .001) and 0.77 (95% CI, 0.68-0.87; P < .001), respectively, demonstrating a high discriminative ability. In addition, poor functional outcomes were not entirely dependent on the development of psychosis, because 40.3% and 45.5% of nonconverters at clinical high risk had poor social and role outcomes, respectively.

CONCLUSIONS AND RELEVANCE

Results from this study support the increasing emphasis on functional decline as a critically important outcome that parallels conversion to psychosis and suggest that both psychosis and long-term functional disability are equally important targets for prevention. Reduced neurocognitive performance, functional impairments, and nonpositive attenuated symptoms at baseline were associated with an increased risk of poor functional outcomes in our sample. Poor functional outcomes were not entirely dependent on positive symptoms and the development of psychosis, further highlighting the need for intervention at this early stage of development for those who do and do not convert to a full-blown psychotic disorder.

Clinical characteristics of patients who have recovered from schizophrenia: the role of empathy and positive-self schema

AIM

This article compares the socio-demographic and clinical characteristics of patients with schizophrenia who recovered with those who achieved remission.

METHODS

Participants were classified based on predetermined criteria for recovery and remission. Data on demographic characteristics, information on duration of untreated psychosis, and assessments of current and historical symptom profiles and socio-occupational functioning emerged from careful chart review and direct interviews. Cross-sectional assessments of clinical variables were derived from the Positive and Negative Syndrome Scale, the Scale for the Assessment of Negative Symptoms, the Personal and Social Performance Scale, the Social Functioning Questionnaire, the Schizophrenia Cognition Rating Scale (ScoRS), the Basic Empathy Scale, and the Brief Core Schema Scales (BCSS).

RESULTS

We found no significant differences between recovered and remitted groups with respect to demographic variables or duration of untreated psychosis. Cognitive and total empathy scores, positive-self schema score on the BCSS, and global score on the ScoRS were significantly higher in the recovered than the remitted group. Furthermore, patients with good levels of empathy and positive-self schema and intact neurocognitive functioning were more likely to achieve recovery.

CONCLUSION

These results suggest that empathy, positive-self schema and neurocognitive functioning may serve as important clinical characteristics distinguishing those patients who have recovered from those who have achieved only remission.

Impairment in functional capacity as an endophenotype candidate in severe mental illness

Impairment in everyday functioning (also referred to as "disability") is a central feature of schizophrenia (SZ) and bipolar disorder, as well as other neuropsychiatric conditions. There is a genetic contribution to both SZ and bipolar illness (BPI), and the primary putative determinant of impairments in everyday functioning across these 2 conditions, cognitive impairments, also show substantial heritability and in fact have been proposed to be endophenotypes for these disorders. In this article, we review data and make our case that impairments in functional capacity, the functional abilities that result in functional disability, may also be a heritable trait that is common across neuropsychiatric illnesses such BPI and SZ. While there has been little previous research on the heritability of these abilities, it is an area receiving substantial research attention. We consider advances in the measurement of cognitive functioning in SZ that may facilitate the discovery of genetic influences on functional capacity. Functional capacity measures are proximal to real-world impairments, measured with suitable psychometric precision to be used in heritability analyses, and appear to be minimally influenced by environmental factors that may cause disability such as environmental factors, symptoms, and disability compensation. Our conclusion is that these functional capacity measures have potential to be the target of genetic analyses and that these measures should be considered across neuropsychiatric conditions where impairments in everyday functioning are present.

Developing models of how cognitive improvements change functioning: mediation, moderation and moderated mediation

BACKGROUND

Cognitive remediation (CRT) affects functioning but the extent and type of cognitive improvements necessary are unknown.

AIM

To develop and test models of how cognitive improvement transfers to work behaviour using the data from a current service.

METHOD

Participants (N49) with a support worker and a paid or voluntary job were offered CRT in a Phase 2 single group design with three assessments: baseline, post therapy and follow-up. Working memory, cognitive flexibility, planning and work outcomes were assessed.

RESULTS

Three models were tested (mediation - cognitive improvements drive functioning improvement; moderation - post treatment cognitive level affects the impact of CRT on functioning; moderated mediation - cognition drives functioning improvements only after a certain level is achieved). There was evidence of mediation (planning improvement associated with improved work quality). There was no evidence that cognitive flexibility (total Wisconsin Card Sorting Test errors) and working memory (Wechsler Adult Intelligence Scale III digit span) mediated work functioning despite significant effects. There was some evidence of moderated mediation for planning improvement if participants had poorer memory and/or made fewer WCST errors. The total CRT effect on work quality was d=0.55, but the indirect (planning-mediated CRT effect) was d=0.082

CONCLUSION

Planning improvements led to better work quality but only accounted for a small proportion of the total effect on work outcome. Other specific and non-specific effects of CRT and the work programme are likely to account for some of the remaining effect. This is the first time complex models have been tested and future Phase 3 studies need to further test mediation and moderated mediation models.

Functional outcomes in schizophrenia: understanding the competence-performance discrepancy

A problem in the study and treatment of functional disability in schizophrenia is that factors other than competence (what one can do) can limit real-world performance (what one does). We examined predictors of the competence-performance discrepancy in both adaptive and interpersonal domains. Patients with schizophrenia (N = 96) were evaluated at baseline of a clinical treatment study. Discrepancy scores were created by considering each subject's competence relative to their real-world performance in interpersonal and adaptive behaviour domains. Logistic regression analyses revealed that for the interpersonal competence-performance discrepancy, living in a group home, better neurocognition, more time spent in the hospital since a first episode of psychosis, and a longer first hospitalization predicted a greater discrepancy between interpersonal competence and performance measures. For adaptive behaviour, shorter time since most recent hospitalization, more depressive symptoms, greater number of months of first hospitalization, older age at baseline, younger age at first hospitalization, and more time spent in the hospital since a first episode of psychosis predicted a greater adaptive competence-performance discrepancy. A different pattern of demographic and clinical features may limit the extent to which patients are deploying interpersonal versus adaptive skills in everyday life.

Facial emotion linked cooperation in patients with paranoid schizophrenia: a test on the Interpersonal Communication Model

BACKGROUND

Patients with schizophrenia consistently show deficits in facial affect perception and social behaviours. It is illusive to suggest that these deficits in facial affect perception cause poor social behaviours.

AIM

The present research aims to study how facial affects influence ingratiation, cooperation and punishment behaviours of the patients.

METHODS

Forty outpatients with paranoid schizophrenia, 26 matched depressed patients and 46 healthy volunteers were recruited. After measurement of clinical symptoms and depression, their facial emotion recognition, neurocognitive functioning and the facial affects dependent cooperative behaviour were measured using a modified version of Mixed-Motive Game.

RESULTS

The depressed control group showed demographic characteristics, depression levels and neurocognitive functioning similar to the schizophrenic group. Patients with schizophrenia committed significantly more errors in neutral face identification than the other two groups. They were significantly more punitive on the Mixed-Motive Game in the neutral face condition.

CONCLUSION

Neutral face misidentification was a unique emotion-processing deficit in the schizophrenic group. Their increase in punitive behaviours in the neutral face condition might confuse their family members and trigger more expressed emotion from them, thus increasing the risk of relapse. Family members might display more happy faces to promote positive relationships with patients.

The relationship of social function to depressive and negative symptoms in individuals at clinical high risk for psychosis

BACKGROUND

Social dysfunction is a hallmark symptom of schizophrenia which commonly precedes the onset of psychosis. It is unclear if social symptoms in clinical high-risk patients reflect depressive symptoms or are a manifestation of negative symptoms.

METHOD

We compared social function scores on the Social Adjustment Scale-Self Report between 56 young people (aged 13-27 years) at clinical high risk for psychosis and 22 healthy controls. The cases were also assessed for depressive and 'prodromal' symptoms (subthreshold positive, negative, disorganized and general symptoms).

RESULTS

Poor social function was related to both depressive and negative symptoms, as well as to disorganized and general symptoms. The symptoms were highly intercorrelated but linear regression analysis demonstrated that poor social function was primarily explained by negative symptoms within this cohort, particularly in ethnic minority patients.

CONCLUSIONS

Although this study demonstrated a relationship between social dysfunction and depressive symptoms in clinical high-risk cases, this association was primarily explained by the relationship of each of these to negative symptoms. In individuals at heightened risk for psychosis, affective changes may be related to a progressive decrease in social interaction and loss of reinforcement of social behaviors. These findings have relevance for potential treatment strategies for social dysfunction in schizophrenia and its risk states and predict that antidepressant drugs, cognitive behavioral therapy and/or social skills training may be effective.

Cognition at illness onset as a predictor of later functional outcome in early psychosis: systematic review and methodological critique

BACKGROUND

Cognitive deficits occur early in the course of psychosis, are mostly stable, and have been identified as potential functional prognostic markers. Previous reviews of chronic schizophrenia have concluded that specific cognitive deficits are strongly associated with poorer functional outcomes. However, results of schizophrenia studies may be influenced by the effects of long-term illness or treatment or be biased toward individuals with poorer outcomes and may not be relevant to early psychosis (EP). This review aimed to systematically examine the evidence regarding general and social cognitive predictors of later functional outcome in EP and critique the methodology of the studies reviewed. A final aim was to conduct a meta-analysis of the studies reviewed, but methodological reasons precluded this.

METHOD

A comprehensive search of PsycINFO and MEDLINE databases identified 15 relevant articles and 7 further articles following a reference list search, totaling 22 included articles.

RESULTS

Most studies found at least one cognitive domain predicted functional outcome, but examination of separate cognitive domains revealed there were more null than significant associations between cognition and functional outcome across every cognitive domain. No study examined social cognition as a predictor of outcome. The frequency with which different cognitive domains predicted outcome varied depending on study methodology and this was most noticeable when studies with short-term follow-up were compared with longer-term follow-up studies.

CONCLUSIONS

Due to the methodological variability and limitations of the studies reviewed, firm conclusions regarding the relationship between cognition and functional outcomes in EP cannot be made. Tentatively, cognition may be prognostic in EP, especially for longer-term outcomes. However, further research that addresses the methodological issues identified, including examination of social cognition and other non-cognitive predictors, is needed.

Cognitive control deficits in schizophrenia: mechanisms and meaning

Although schizophrenia is an illness that has been historically characterized by the presence of positive symptomatology, decades of research highlight the importance of cognitive deficits in this disorder. This review proposes that the theoretical model of cognitive control, which is based on contemporary cognitive neuroscience, provides a unifying theory for the cognitive and neural abnormalities underlying higher cognitive dysfunction in schizophrenia. To support this model, we outline converging evidence from multiple modalities (eg, structural and functional neuroimaging, pharmacological data, and animal models) and samples (eg, clinical high risk, genetic high risk, first episode, and chronic subjects) to emphasize how dysfunction in cognitive control mechanisms supported by the prefrontal cortex contribute to the pathophysiology of higher cognitive deficits in schizophrenia. Our model provides a theoretical link between cellular abnormalities (eg, reductions in dentritic spines, interneuronal dysfunction), functional disturbances in local circuit function (eg, gamma abnormalities), altered inter-regional cortical connectivity, a range of higher cognitive deficits, and symptom presentation (eg, disorganization) in the disorder. Finally, we discuss recent advances in the neuropharmacology of cognition and how they can inform a targeted approach to the development of effective therapies for this disabling aspect of schizophrenia.

Association of demographic characteristics, symptomatology, retrospective and prospective memory, executive functioning and intelligence with social functioning in schizophrenia

OBJECTIVE

The objective of this study was to explore the influence of socio-demographic and clinical factors and neurocognitive variables (i.e. prospective and retrospective memory, executive functioning, and intelligence) on social functioning in Chinese schizophrenia patients.

METHODS

The study sample comprised 110 Chinese schizophrenia patients. Their clinical condition and social functioning were evaluated with the Brief Psychiatric Rating Scale (BPRS) and the Functional Needs Assessment (FNA), respectively. Three prospective memory (PM) tasks (time-, event-, and activity-based), three tests of executive functioning (the Design Fluency Test [DFT], Tower of London [TOL], and Wisconsin Card Sorting Test [WCST]), one test of intelligence (Raven's Progressive Matrices), and two retrospective memory (RM) tasks (the immediate and delayed recall conditions of the Logical Memory subtest of the Wechsler Memory Scales-Revised [WMS-R]) were administered to all patients.

RESULTS

In correlation analyses higher education and better performance on the WCST (categories completed) and the Logical Memory subtests (delayed and immediate) of the WMS-R are significantly correlated with better social functioning, whereas a lower WCST score (perseverative errors) and more severe negative symptoms are associated with poorer social functioning. Multiple linear regression analysis revealed that higher education and a lower WCST score (perseverative errors) independently contribute to better social functioning.

CONCLUSIONS

Unexpectedly, most socio-demographic and clinical factors do not seem to have a significant impact on social functioning of Chinese schizophrenia patients living in a Chinese society. Negative symptoms and certain cognitive deficits were the main predictors of social functioning and they should be the main targets for antipsychotic treatment and psychosocial interventions to improve social adjustment in Chinese schizophrenia patients.

Disorganization and reality distortion in schizophrenia: a meta-analysis of the relationship between positive symptoms and neurocognitive deficits

BACKGROUND

Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from other types of positive symptoms such as reality distortion (delusions and hallucinations). Although some studies have found that disorganization is more strongly linked to neurocognitive deficits and poor functional outcomes than reality distortion, the findings are not always consistent.

METHODS

A meta-analysis of 104 studies (combined n=8015) was conducted to determine the magnitude of the relationship between neurocognition and disorganization as compared to reality distortion. Additional analyses were conducted to determine whether the strength of these relationships differed depending on the neurocognitive domain under investigation.

RESULTS

The relationship between reality distortion and neurocognition was weak (r=-.04; p=.03) as compared to the moderate association between disorganization and neurocognition (r=-.23; p<.01). In each of the six neurocognitive domains that were examined, disorganization was more strongly related to neurocognition (r's range from -.20 to -.26) than to reality distortion (r's range from .01 to -.12).

CONCLUSIONS

The effect size of the relationship between neurocognition and disorganization was significantly larger than the effect size of the relationship between neurocognition and reality distortion. These results hold across several neurocognitive domains. These findings support a dimensional view of positive symptoms distinguishing disorganization from reality distortion.

The relationship between neurocognition and social cognition with functional outcomes in schizophrenia: a meta-analysis

The current systematic review and meta-analysis provides an extended and comprehensive overview of the associations between neurocognitive and social cognitive functioning and different types of functional outcome. Literature searches were conducted in MEDLINE and PsycINFO and reference lists from identified articles to retrieve relevant studies on cross-sectional associations between neurocognition, social cognition and functional outcome in individuals with non-affective psychosis. Of 285 studies identified, 52 studies comprising 2692 subjects met all inclusion criteria. Pearson correlations between cognition and outcome, demographic data, sample sizes and potential moderator variables were extracted. Forty-eight independent meta-analyses, on associations between 12 a priori identified neurocognitive and social cognitive domains and 4 domains of functional outcome yielded a number of 25 significant mean correlations. Overall, social cognition was more strongly associated with community functioning than neurocognition, with the strongest associations being between theory of mind and functional outcomes. However, as three-quarters of variance in outcome were left unexplained, cognitive remediation approaches need to be combined with therapies targeting other factors impacting on outcome.

Determinants of work outcome in neuroleptic-resistant schizophrenia and schizoaffective disorder: cognitive impairment and clozapine treatment

There is considerable evidence that cognitive impairment is a better predictor of work and social function in schizophrenia than are positive and negative symptoms. Atypical antipsychotic drugs have been shown to improve cognitive function in schizophrenia patients, but it is unclear whether this improves patients' ability to gain employment. Data from a prospective longitudinal study was used to test the hypotheses that (1) clozapine treatment would improve employment outcome in treatment-resistant schizophrenia or schizoaffective disorder patients, and (2) specific cognitive functioning at baseline and after treatment would predict work status at baseline and change in work status. Employment status and cognitive assessment data were collected in 59 treatment-resistant schizophrenia or schizoaffective disorder patients. Forty-seven of 59 (79.7%) patients were unemployed at baseline. Over a 12-month period, 23 (48.9%) additional patients were able to gain paid or volunteer jobs, or attend school. As predicted, neurocognitive performance was a better predictor of employment status and ability to gain of employment than clinical symptoms. Improvement in verbal working memory was found to be a better predictor of employment outcome than other cognitive functions. Treatment that enhances cognitive function, especially verbal working memory, may lead to better employment outcomes in treatment-resistant schizophrenia or schizoaffective disorder patients.

Genetics and intermediate phenotypes of the schizophrenia--bipolar disorder boundary

Categorization of psychotic illnesses into schizophrenic and affective psychoses remains an ongoing controversy. Although Kraepelinian subtyping of psychosis was historically beneficial, modern genetic and neurophysiological studies do not support dichotomous conceptualization of psychosis. Evidence suggests that schizophrenia and bipolar disorder rather present a clinical continuum with partially overlapping symptom dimensions, neurophysiology, genetics and treatment responses. Recent large scale genetic studies have produced inconsistent findings and exposed an urgent need for re-thinking phenomenology-based approach in psychiatric research. Epidemiological, linkage and molecular genetic studies, as well as studies in intermediate phenotypes (neurocognitive, neurophysiological and anatomical imaging) in schizophrenia and bipolar disorders are reviewed in order to support a dimensional conceptualization of psychosis. Overlapping and unique genetic and intermediate phenotypic signatures of the two psychoses are comprehensively recapitulated. Alternative strategies which may be implicated into genetic research are discussed.

Sex differences in neuropsychological functioning among schizophrenia patients

OBJECTIVES

Evidence from the literature addressing sex differences in cognition in schizophrenia remains equivocal, with some researchers suggesting that male schizophrenia patients are more impaired than female subjects, while others report no significant sex differences in cognitive functioning. The aim of the present study was to investigate whether the differential pattern of cognitive performance observed in healthy men and women is preserved in male and female schizophrenia patients.

METHOD

Ninety-six schizophrenia patients (56 men) were compared with 62 age- and gender-ratio matched healthy controls (31 men), on a battery of neuropsychological tests that assessed basic cognitive abilities: attention, working memory, abstraction, inhibition, fluency, verbal learning and memory, visual memory, visuospatial skills, and psychomotor speed.

RESULTS

As a group, schizophrenia patients were significantly impaired in each of the cognitive domains assessed, with the exception of psychomotor speed. The effect of sex was significant for verbal learning and memory, wherein women outperformed men. No significant group x sex interactions were found in any cognitive domains, indicating that the female advantage typically observed in verbal learning and memory remained the same in the schizophrenia patients.

CONCLUSION

The degree of cognitive impairment is the same for male and female schizophrenia patients. Those sex differences found among the patients were typical of the healthy population as well. Therefore, differential decrements in basic cognitive domains do not appear to account for the favourable course of schizophrenia in women relative to men.

Defining "good" and "poor" outcomes in patients with schizophrenia or schizoaffective disorder: a multidimensional data-driven approach

The study's goal was to characterize the typology of patient outcomes based on social and occupational functioning and psychiatric symptoms following antipsychotic drug treatment, and to explore predictors of group membership representing the best/worst outcomes. A hierarchical cluster analysis was used to define groups of patients (n=1449) based on endpoint values for psychiatric symptoms, social functioning, and useful work measured up to 30 weeks of treatment. Stepwise logistic regression was used to construct predictive models of cluster membership for baseline predictors, and with 2/4/8 weeks of treatment. Five distinct clusters of patients were identified at endpoint (Clusters A-E). Patients in Cluster A (25.6%, best outcome) had minimal psychiatric symptoms and mild functional impairment, while patients in Cluster D (14.3%) and E (14.8%) (worst outcome) had moderate-to-severe symptoms and severe functional impairment. Occupational functioning, disorganized thinking, and positive symptoms were sufficient to describe the clusters. Membership in the best/worst clusters was predicted by baseline scores for functioning and symptom severity, and by early changes in symptoms with treatment. Psychiatric symptoms and functioning provided complementary information to describe treatment outcomes. Early symptom response significantly improved the prediction of outcome, suggesting that early monitoring of treatment response may be useful in clinical practice.

Symptoms as mediators of the relationship between neurocognition and functional outcome in schizophrenia: a meta-analysis

BACKGROUND

Neurocognitive functioning in schizophrenia has received considerable attention because of its robust prediction of functional outcome. Psychiatric symptoms, in particular negative symptoms, have also been shown to predict functional outcome, but have garnered much less attention. The high degree of intercorrelation among all of these variables leaves unclear whether neurocognition has a direct effect on functional outcome or whether that relationship to functional outcome is partially mediated by symptoms.

METHODS

A meta-analysis of 73 published English language studies (total n=6519) was conducted to determine the magnitude of the relationship between neurocognition and symptoms, and between symptoms and functional outcome. A model was tested in which symptoms mediate the relationship between neurocognition and functional outcome. Functional outcome involved measures of social relationships, school and work functioning, and laboratory assessments of social skill.

RESULTS

Although negative symptoms were found to be significantly related to neurocognitive functioning (p<.01) positive symptoms were not (p=.97). The relationship was moderate for negative symptoms (r=-.24, n=4757, 53 studies), but positive symptoms were not at all related to neurocogniton (r=.00, n=1297, 25 studies). Negative symptoms were significantly correlated with functional outcome (r=-.42, p<.01), and again the correlation was higher than for positive symptoms (r=-.03, p=.55). Furthermore, our findings support a model in which negative symptoms significantly mediate the relationship between neurocognition and functional outcome (Sobel test p<.01).

CONCLUSIONS

Although neurocognition and negative symptoms are both predictors of functional outcome, negative symptoms might at least partially mediate the relationship between neurocognition and outcome.

Affect recognition as an independent social function determinant in schizophrenia

INTRODUCTION

Facial affect recognition deficits may represent specific deficits and contribute to social dysfunction in patients with schizophrenia. Whether their impacts on social dysfunction are independent to those caused by deficits in basic neurocognition and clinical symptoms needs to be further delineated.

METHOD

Association patterns between affect recognition and basic neurocognitive abilities in 40 acute and 33 stable patients with schizophrenia were compared to explore whether their interrelationships changed across clinical stages. The independent contribution of affect recognition deficits to social dysfunction was explored by multivariate models controlling for general intellectual ability, basic neurocognition, and clinical symptoms.

RESULTS

Affect recognition deficits were associated with social role performances, self-care, and contributed independently to global social functioning in stable patients but not in acute patients. Conversely, affect recognition deficits were associated with impaired basic neurocognitions in acute patients but not in stable patients.

CONCLUSION

In stabilized community patients with schizophrenia, affect recognition deficits were relatively independent to basic neurocognition and had significant social functional consequences.

Remission in schizophrenia: the relationship to baseline symptoms and changes in symptom domains during a one-year study

The concepts of partial recovery and remission have become increasingly important for the evaluation of the effectiveness of schizophrenia therapeutics. The relationship of baseline symptoms and changes in symptoms to remission of psychosis was evaluated. Fifty-six outpatients with residual schizophrenia completed a double-blind trial of olanzapine versus haloperidol and were then enrolled into a one-year open-label trial of olanzapine. Out of these 56 subjects, 13 (23%) met remission criteria at the beginning of the open-label treatment and were excluded. During the one-year study, 7/43 (16%) subjects met remission criteria. These subjects had significantly lower baseline ratings for tardive dyskinesia (TD) than subjects who did not achieve remission (1.8 +/- 1.5 vs. 4.2 +/- 4.6, P = 0.03). As expected, remitted subjects had significantly greater improvements in Brief Psychiatric Rating Scale total scores, positive subscale scores and scale for the Assessment of Negative Symptoms total scores. Remitted subjects also experienced a significantly greater improvement in depressive symptoms (P = 0.001), activation (P = 0.005), and Clinical Global Impressions scores (P < 0.001), as well as greater improvements in extrapyramidal symptoms (P = 0.007) and TD (P < 0.001). These results suggest that the relationship of depressive symptoms and improved side effects to the construct of remission in schizophrenia may deserve special attention. Future studies should aim to relate remission criteria to functional outcomes, cognition, and other important symptom domains.

Predictors of change in life skills in schizophrenia after cognitive remediation

Few studies have investigated predictors of response to cognitive remediation interventions in patients with schizophrenia. Predictor studies to date have selected treatment outcome measures that were either part of the remediation intervention itself or closely linked to the intervention with few studies investigating factors that predict generalization to measures of everyday life-skills as an index of treatment-related improvement. In the current study we investigated the relationship between four measures of neurocognitive function, crystallized verbal ability, auditory sustained attention and working memory, verbal learning and memory, and problem-solving, two measures of symptoms, total positive and negative symptoms, and the process variables of treatment intensity and duration, to change on a performance-based measure of everyday life-skills after a year of computer-assisted cognitive remediation offered as part of intensive outpatient rehabilitation treatment. Thirty-six patients with schizophrenia or schizoaffective disorder were studied. Results of a linear regression model revealed that auditory attention and working memory predicted a significant amount of the variance in change in performance-based measures of everyday life skills after cognitive remediation, even when variance for all other neurocognitive variables in the model was controlled. Stepwise regression revealed that auditory attention and working memory predicted change in everyday life-skills across the trial even when baseline life-skill scores, symptoms and treatment process variables were controlled. These findings emphasize the importance of sustained auditory attention and working memory for benefiting from extended programs of cognitive remediation.

IQ as a predictor of functional outcome in schizophrenia: a longitudinal, four-year study of first-episode psychosis

Studies of established schizophrenia have consistently found that cognitive function predicts social and clinical outcomes. The findings from first-episode studies have been more variable, with only some studies reporting predictive relationships. We tested the possibility that an index of general cognitive ability, IQ, may be a more sensitive and reliable predictor of outcome in first-episode schizophrenia than specific measures of memory and executive function. Fifty-four patients with first-episode schizophrenia or schizoaffective disorder were assessed for cognitive and social function as well as symptoms at three time points over the four years following first presentation of their psychotic illness. Regression analyses were performed to determine whether IQ and specific neuropsychological measures at first episode and one-year follow-up predicted four-year social function and residual symptoms. The effects of premorbid and concurrent IQ on outcome were also assessed. Premorbid IQ and IQ at each assessment significantly predicted social function at four-year follow-up. This relationship remained significant after the social function or symptom scores at first presentation were accounted for in the regression. Specific measures predicted certain domains of social function, but these were weaker and less consistent than IQ. The predictive values of cognition on residual symptoms were less strong; the most consistent finding was a relationship between IQ and the negative syndrome. This study suggests that early in the course of schizophrenia, general cognitive ability, as measured by IQ, is a more sensitive and reliable predictor of functional outcome than measures of specific ability.

Measuring specific, rather than generalized, cognitive deficits and maximizing between-group effect size in studies of cognition and cognitive change

While cognitive impairment in schizophrenia is easy to demonstrate, it has been much more difficult to measure a specific cognitive process unconfounded by the influence of other cognitive processes and noncognitive factors (eg, sedation, low motivation) that affect test scores. With the recent interest in the identification of neurophysiology-linked cognitive probes for clinical trials, the issue of isolating specific cognitive processes has taken on increased importance. Recent advances in research design and psychometric theory regarding cognition research in schizophrenia demonstrate the importance of (1) maximizing between-group differences via reduction of measurement error during both test development and subsequent research and (2) the development and use of process-specific tasks in which theory-driven performance indices are derived across multiple conditions. Use of these 2 strategies can significantly advance both our understanding of schizophrenia and measurement sensitivity for clinical trials. Novel data-analytic strategies for analyzing change across multiple conditions and/or multiple time points also allow for increased reliability and greater measurement sensitivity than traditional strategies. Following discussion of these issues, trade-offs inherent to attempts to address psychometric issues in schizophrenia research are reviewed. Finally, additional considerations for maximizing sensitivity and real-world significance in clinical trials are discussed.

Symptoms versus neurocognition as predictors of change in life skills in schizophrenia after outpatient rehabilitation

A growing body of literature has shown that neurocognitive deficits in schizophrenia account for 20-60% of the variance in measures of outcome, and in many studies are more closely related to outcome than symptoms [Green, M.F., Kern, R.S., Braff, D.L., Mintz, J., 2000. Neurocognitive deficits and functional outcome in schizophrenia: are we measuring the "right stuff"? Schizophr. Bull. 26(1), 119-136; Green, M.F., Kern, R.S., Heaton, R.K., 2004. Longitudinal studies of cognition and functional outcome in schizophrenia: implications for MATRICS. Schizophr. Res. 72(1), 41-51]. Most of these studies have been cross-sectional, few longitudinal studies have investigated the degree to which neurocognition and symptoms predict ability to benefit from outpatient rehabilitation, and no longitudinal studies use measures of everyday life skills that are performance-based. In the current study we investigated the relationship between five measures of neurocognitive function, crystallized verbal ability, visual sustained vigilance, verbal learning, problem-solving, and processing speed, and two measures of symptoms, total positive and negative symptoms, and change on a performance-based measure of everyday life skills after a year of outpatient rehabilitation. Rehabilitation consisted of both psychosocial and cognitive interventions. Forty-six patients with schizophrenia or schizoaffective disorder were studied. Results of a linear regression model revealed that verbal learning predicted a significant amount of the variance in change in performance-based measures of everyday life skills after outpatient rehabilitation, even when variance for all other variables in the model was accounted for. Measures of crystallized verbal ability, sustained visual vigilance, problem-solving, processing speed and symptoms were not linked to functional status change. These findings emphasize the importance of verbal learning for benefiting from psychosocial and cognitive rehabilitation interventions, and suggest the development of alternative rehabilitation strategies for those who do not benefit.

Imitation, simulation, and schizophrenia

The social significance of imitation is that it provides internal tools for understanding the actions of others by simulating or forming internal representations of these actions. Imitation plays a central role in human social behavior by mediating diverse forms of social learning. However, imitation and simulation ability in schizophrenia has not been adequately addressed. The major aim of the present study was to investigate imitation ability in schizophrenia patients and healthy individuals by examining simple motor imitation that involved the replication of meaningless manual and oral gestures, and the imitation of emotional facial expressions, which has implications for mentalizing. A secondary aim of the present study was to investigate the relationships among imitation ability, social functioning, and working memory. Subjects were asked to mimic hand gestures, mouth movements, and facial expressions of others, online. Clinical symptoms, social competence, and working memory were also assessed. Patients with schizophrenia were significantly impaired on all imitation tasks. Imitation errors were significantly correlated with reduced social competence and increased negative symptoms. However, imitation ability was only weakly associated with working memory. To summarize, the present study examined the ability of patients with schizophrenia to imitate the behaviors demonstrated by others. The results indicate a fundamental impairment in imitation ability in schizophrenia and implicate a possible difficulty in simulation. Further research to determine the neural and developmental origins of this difficulty could be extremely helpful in elucidating the role of simulation in schizophrenia and to establish the complex relationships among mental representation, imitation, and social cognition.