Do specific neurocognitive deficits predict specific domains of community function in schizophrenia?

Frontal brain volume correlates of impaired executive function in schizophrenia

Cognitive impairments affect functional capacity in individuals with schizophrenia (SZH), but their neural basis remains unclear. The Wisconsin Card Sorting Test (WCST), and the Stroop Task (SCWT), are paradigmatic tests which have been used extensively for examining executive function in SZH. However, few studies have explored how deficits on these tasks link to brain volume differences commonly seen in SZH. Here, for the first time, we tested associations between FreeSurfer-derived frontal brain volumes and performance on both WCST and SCWT, in a well-matched sample of 57 SZH and 32 control subjects. We also explored whether these associations were dissociable from links to symptom severity in SZH. Results revealed correlations between volumes and task performance which were unique to SZH. In SZH only, volumes of right middle frontal regions correlated with both WCST and Stroop performance: correlation coefficients were significantly different to those present in the control group, highlighting their specificity to the patient group. In the Stroop task, superior frontal regions also showed associations with Stroop interference scores which were unique to SZH. These findings provide important detail around how deficits on these two paradigmatic executive function tasks link to brain structural differences in SZH. Results align with converging evidence suggesting that neuropathology within right middle frontal regions (BA9 and BA46) might be of particular import in SZH. No volumetric associations with symptom severity were found, supporting the notion that the structural abnormalities underpinning cognitive deficits in SZH differ from those associated with symptomatology.

The effect of exercise on cognition and clinical symptoms of patients with schizophrenia: A systematic review of randomized controlled trial

Physical activity has been viewed as a potential non-pharmacological therapeutic strategy to improve the clinical symptoms and neurocognitive deficits in patients with schizophrenia. However, there are various types of physical activities, and different exercise prescriptions might produce inconsistent benefits. Thus, this study aimed to conduct a systematic review of exercise interventions for patients with schizophrenia, clarifying the benefits of these interventions on cognitive function and clinical symptoms. This review encompasses six electronic databases, with inclusion criteria including randomized controlled trial designs, participants with schizophrenia, and a comprehensive exercise intervention program. Twenty-seven studies met the inclusion criteria, incorporating data from 1549 patients with schizophrenia. The results highlight that when comparing the exercise intervention group to the non-intervention control group, patients with schizophrenia showed significant improvement in negative symptoms. Structured exercise interventions can help improve the negative symptoms of schizophrenia, filling the gaps where medication falls short. Regarding functional outcomes, exercise interventions aid in enhancing the overall functionality (psychological, social, occupational) of individuals with schizophrenia. The improvement is largely tied to the boost in physical fitness that exercise provides. Based on current findings, exercise interventions assist in enhancing cognitive function in patients with schizophrenia. Notably, significant improvements are observed in higher-order cognitive functions, including processing speed, attention, and working memory. It is recommended to engage in moderate-intensity exercises at least three times a week, with each session lasting a minimum of 30min. Well-structured exercise interventions contribute to enhancing the negative symptoms and cognitive functions in patients with schizophrenia.

Benefits of video games for people with schizophrenia: a literature review

PURPOSE OF REVIEW

In spite of the overwhelming concerns about the deleterious impact of exposure to video games, a growing body of evidence suggests that it may be of potential interest for therapeutic purposes, particularly in schizophrenia. As literature is rapidly evolving, we carried out a systematic review of recent articles on this issue.

RECENT FINDINGS

We identified seven studies published from 2017 to 2022 exploring the benefits of commercial video games in people with schizophrenia and related disorders regarding symptoms, cognition and functional outcome. Six studies used an RCT design. Associations between gaming and better outcomes were found in three main areas: physical condition (walking speed, aerobic fitness), neurocognition (processing speed, memory and executive functions), and social functioning, self-efficacy in daily life activities and quality of life.

SUMMARY

Active use of video games is associated with better aerobic fitness and cognitive performances. Video gaming may contribute to better functional outcome and quality of life in patients suffering from cognitive impairments and difficulties in social functioning. Persons with schizophrenia may benefit from using commercial video games because of their potential therapeutic impact on functioning and cognition.

Characteristic association of symbol coding test score with occupational function in Japanese patients with schizophrenia

AIM

Studies showed that cognitive function affects occupational function in patients with schizophrenia. This study aimed to determine the effects of cognitive function on occupational function in Japanese patients with schizophrenia using the Brief Assessment of Cognition in Schizophrenia (BACS).

METHODS

Participants were 198 outpatients with schizophrenia or schizoaffective disorder (66 females; mean age 34.5 ± 6.8 years). Occupational function was assessed using the work subscale of the Life Assessment Scale for Mental Ill (LASMI-w). Multiple regression analysis was performed using the BACS as the independent variable and LASMI-w as the dependent variable. Furthermore, we divided the LASMI-w score into three groups, <11, 11-20, and >21, and performed a multinomial logistic regression analysis.

RESULTS

Multiple regression analysis revealed that LASMI-w score was negatively associated with BACS composite score (β = -0.20, p < 0.01). Among the sub-items of the BACS, only the symbol-coding score showed a significant negative association (β = -0.19, p < 0.05). Multinomial logistic analysis showed that the better the composite and symbol coding scores, the smaller the impairment of the occupational function (composite score: β = 2.39 between mild and moderate occupational impairments, p < 0.05; symbol coding score: β = 2.44 between mild and severe impairments, p < 0.05).

CONCLUSION

The occupational function of patients with schizophrenia was associated with overall cognitive function (composite score). In particular, the symbol coding score of the BACS was suggested to be related to work ability. These results might be useful in the assessment and training of cognitive rehabilitation aimed at employment support.

Disruptions in white matter microstructure associated with impaired visual associative memory in schizophrenia-spectrum illness

Episodic memory ability relies on hippocampal-prefrontal connectivity. However, few studies have examined relationships between memory performance and white matter (WM) microstructure in hippocampal-prefrontal pathways in schizophrenia-spectrum disorder (SSDs). Here, we investigated these relationships in individuals with first-episode psychosis (FEP) and chronic schizophrenia-spectrum disorders (SSDs) using tractography analysis designed to interrogate the microstructure of WM tracts in the hippocampal-prefrontal pathway. Measures of WM microstructure (fractional anisotropy [FA], radial diffusivity [RD], and axial diffusivity [AD]) were obtained for 47 individuals with chronic SSDs, 28 FEP individuals, 52 older healthy controls, and 27 younger healthy controls. Tractography analysis was performed between the hippocampus and three targets involved in hippocampal-prefrontal connectivity (thalamus, amygdala, nucleus accumbens). Measures of WM microstructure were then examined in relation to episodic memory performance separately across each group. Both those with FEP and chronic SSDs demonstrated impaired episodic memory performance. However, abnormal WM microstructure was only observed in individuals with chronic SSDs. Abnormal WM microstructure in the hippocampal-thalamic pathway in the right hemisphere was associated with poorer memory performance in individuals with chronic SSDs. These findings suggest that disruptions in WM microstructure in the hippocampal-prefrontal pathway may contribute to memory impairments in individuals with chronic SSDs but not FEP.

It is time to address language disorders in schizophrenia: A RCT on the efficacy of a novel training targeting the pragmatics of communication (PragmaCom)

INTRODUCTION

Language and communication disruptions in schizophrenia are at the center of a large body of investigation. Yet, the remediation of such disruptions is still in its infancy. Here we targeted what is known to be one of the most damaged language domains in schizophrenia, namely pragmatics, by conducting a pragmatics-centered intervention with a randomized controlled trial design and assessing also durability and generalization. To the best of our knowledge, this is the first study with these characteristics.

METHODS

Inspired by the Gricean account of natural language use, we tailored a novel treatment addressing the pragmatics of communication (PragmaCom) and we tested its efficacy in a sample of individuals with schizophrenia randomized to the experimental group or to an active control group. The primary outcome with respect to the efficacy of the PragmaCom was measured by changes in pragmatic abilities (as evaluated with the global score of the Assessment of Pragmatic Abilities and Cognitive Substrates test) from baseline to 12 weeks and at 3-month follow-up. The secondary outcome was measured by changes in metaphor comprehension, abstract thinking, and global functioning from baseline to 12 weeks and at 3-month follow-up.

RESULTS

Relative to the control group, at post-test the PragmaCom group showed greater and enduring improvement in global pragmatic skills and in metaphor comprehension. At follow-up, these improvements persisted and the PragmaCom exerted beneficial effects also on functioning.

CONCLUSIONS

Despite the limited sample size, we believe that these findings offer initial yet encouraging evidence of the possibility to improve pragmatic skills with a theoretically grounded approach and to obtain durable and clinically relevant benefits. We argue that it is time that therapeutic efforts embrace communicative dysfunctions in order to improve illness outcome.

Functional Performance and the Allen Cognitive Level Screen for Adults With Mental Illness: A Scoping Review

IMPORTANCE

Research involving the use of the Allen Cognitive Level Screen (ACLS) in mental health practice has been available for more than 40 yr, yet there has been no comprehensive synthesis and review of this body of literature.

OBJECTIVE

To review, summarize, compare, and evaluate the existing literature regarding the relationship between the ACLS and the functional and adaptive functional performance of adults living with mental illness.

DATA SOURCES

Searches with no date limits were conducted in the CINAHL, MEDLINE, PsycINFO, ProQuest, and OTseeker databases. Study Selection and Data Collection: A five-stage scoping review methodology was used to examine peer-reviewed English-language literature reporting on the relationship between ACLS scores and functional and adaptive functional performance of adults with mental illness. Information from 15 studies was charted, collated, and numerically and thematically summarized.

FINDINGS

A positive relationship between ACLS scores and in-the-moment performance was consistently reported. The relationship of ACLS scores to community living performance was less consistent. Methods of assessing performance, complexity of tasks assessed, and timing of assessments affected relationships with cognition as measured by ACLS. Gaps in the literature were identified.

CONCLUSIONS AND RELEVANCE

Findings raise questions about how, why, and when occupational therapists use the ACLS. Increased examination is needed of what aspects of performance and functional cognition reliably determine people's ability to live successfully in the community. What This Article Adds: This article provides the first synthesis of the existing literature on the relationship between ACLS scores and functional and adaptive functional performance of people living with mental illness.

Adjunctive yoga training for persons with schizophrenia: who benefits?

OBJECTIVE

The aim of this study was to identify factors associated with acceptability and efficacy of yoga training (YT) for improving cognitive dysfunction in individuals with schizophrenia (SZ).

METHODS

We analysed data from two published clinical trials of YT for cognitive dysfunction among Indians with SZ: (1) a 21-day randomised controlled trial (RCT, N = 286), 3 and 6 months follow-up and (2) a 21-day open trial (n = 62). Multivariate analyses were conducted to examine the association of baseline characteristics (age, sex, socio-economic status, educational status, duration, and severity of illness) with improvement in cognition (i.e. attention and face memory) following YT. Factors associated with acceptability were identified by comparing baseline demographic variables between screened and enrolled participants as well as completers versus non-completers.

RESULTS

Enrolled participants were younger than screened persons who declined participation (t = 2.952, p = 0.003). No other characteristics were associated with study enrollment or completion. Regarding efficacy, schooling duration was nominally associated with greater and sustained cognitive improvement on a measure of facial memory. No other baseline characteristics were associated with efficacy of YT in the open trial, the RCT, or the combined samples (n = 148).

CONCLUSIONS

YT is acceptable even among younger individuals with SZ. It also enhances specific cognitive functions, regardless of individual differences in selected psychosocial characteristics. Thus, yoga could be incorporated as adjunctive therapy for patients with SZ. Importantly, our results suggest cognitive dysfunction is remediable in persons with SZ across the age spectrum.

Modelling change in neurocognition, symptoms and functioning in young people with emerging mental disorders

Mental disorders and their functional impacts evolve dynamically over time. Neurocognition and clinical symptoms are commonly modelled as predictors of functioning, however, studies tend to rely on static variables and adult samples with chronic disorders, with limited research investigating change in these variables in young people with emerging mental disorders. These relationships were explored in a longitudinal clinical cohort of young people accessing early intervention mental health services in Australia, around three-quarters of whom presented with a mood disorder (N = 176, aged 12-30 at baseline). Bivariate latent change score models quantified associations between neurocognition (a latent variable of working memory, verbal memory, visuospatial memory, and cognitive flexibility), global clinical symptoms, and functioning (self- and clinician-rated) and their relative change over follow-up (median = 20 months). We found that longitudinal changes in functioning were coupled with changes in global clinical symptoms (β = -0.43, P < 0.001), such that improvement in functioning was related to improvement in clinical symptoms. Changes in neurocognition were not significantly associated with changes in functioning or clinical symptoms. Main findings were upheld in three sensitivity analyses restricting the sample to: (a) adults aged 18-30; (b) participants with 12-24 months of follow-up; and (c) participants without a psychotic disorder. Our findings show that global symptom reduction and functional improvement are related in young people with emerging mental disorders. More work is needed to determine the temporal precedence of change in these variables. Future studies should apply this methodology to intervention studies to untangle the causal dynamics between neurocognition, symptoms, and functioning.

Training Inhibitory Control Induced Robust Neural Changes When Behavior Is Affected: A Follow-up Study Using Cognitive Event-Related Potentials

Cognitive training results in significant, albeit modest, improvements in specific cognitive functions across a range of mental illnesses. Inhibitory control, defined as the ability to stop the execution of an automatic reaction or a planned motor behavior, is known to be particularly important for the regulation of health behaviors, including addictive behaviors. For example, several studies have indicated that inhibitory training can lead to reduced alcohol consumption or a loss of weight/reduced energy intake. However, the exact neurocognitive mechanisms that underlie such behavioral changes induced by training are still matter of debate. In the present study, we investigated the long-term impact (ie, at 1 week posttraining) of an inhibitory training program (composed of 4 consecutive daily training sessions of 20 minutes each) on the performance of a Go/No-go task. Healthy participants were randomly assigned to 1 of 3 designated groups: (1) an Inhibition Training (IT) group that received training based on a hybrid flanker Go/No-go task; (2) a group that received a noninhibition-based (ie, episodic memory; EM) training; and (3) a No-Training (NT) group to control for test-retest effects. Each group underwent 3 sessions of a Go/No-go task concomitant with the recording of event-related potentials. Our results revealed a specific impact of the Inhibitory Training on the Go/No-go task, indexed by a faster process compared with the other 2 groups. This effect was neurophysiologically indexed by a faster N2 component on the difference NoGo-Go waveform. Importantly, effects at both the behavioral and at the neural level were still readily discernible 1 week posttraining. Thus, our data clearly corroborate the notion that cognitive training is effective, while also indicating that it may persist over time.

[Cognitive disorders in schizophrenia]

Cognitive disorders in schizophrenia are highly correlated with the psychosocial level (e.g. relationships, quality of life and work). It has been shown that healthy relatives and people at ultrahigh risk also display cognitive dysfunctions albeit to a lesser degree. The cognitive impairment increases simultaneously with an acute phase and then reverts back to baseline levels. At the psychopathological level, negative symptoms and the disorganization syndrome show the strongest associations with cognitive deficits, whereby the extent of manifestation of deficits increases with increasing symptomatology. Cognitive remediation can improve the cognitive performance through training with small to moderate effects. With respect to drug therapy there is currently no drug with a positive effect on cognitive disorders.

P50 inhibition deficit in patients with chronic schizophrenia: Relationship with cognitive impairment of MATRICS consensus cognitive battery

OBJECTIVE

Cognitive impairment is a core symptom of schizophrenia (SCZ); however, its pathophysiological mechanisms remain unclear. The sensory gating (SG) deficits reflected by P50 inhibition are recurring in SCZ, and this inhibition may be related to the cognitive deficits seen in these individuals. This study aimed to investigate the relationship between P50 inhibition and cognitive dysfunction in SCZ, which has not been fully investigated up to this point.

METHODS

A total of 270 individuals with chronic SCZ and 116 healthy controls were enrolled in the study. Psychopathology of SCZ was rated by the positive and negative syndrome scale (PANSS), while cognitive function and P50 inhibition of subjects were assessed by the MATRICS Consensus Cognitive Battery (MCCB) and the electroencephalography system.

RESULTS

The MCCB total and its 10 index scores were significantly lower in patients than those in healthy controls (all p < 0.001). SCZ patients had a lower amplitude of S1, and higher P50 ratio than healthy controls (both p < 0.01). However, there were no significant correlations between the P50 ratio and any of the PANSS total and its subscale scores in SCZ patients (all p > 0.05). Moreover, no correlation was found between the P50 components and the MCCB scores (all p > 0.05).

CONCLUSIONS

Our findings suggest that the P50 inhibition deficits occur in Chinese individuals with SCZ, which may not be associated with their clinical symptoms and cognitive impairment.

Neural changes following cognitive remediation therapy for schizophrenia

Patients with schizophrenia experience cognitive impairments that relate to poorer social functioning even after amelioration of positive symptoms. Pharmacological treatment and cognitive remediation are the two important therapeutic approaches for cognitive impairment in schizophrenia. Cognitive remediation therapy (CRT) for schizophrenia improves cognitive functioning and induces neuroplasticity, but different approaches and durations of CRT and different neuroimaging devices have led to varying results in meta-analyses. The objective of this review was to explore the impact of CRT on neurobiology. Several studies have provided evidence of increased activation in the frontal brain regions, such as the prefrontal cortex, anterior cingulate cortex, and parietal and occipital regions during working memory or executive function tasks after CRT. Two studies have shown alterations in resting-state connectivity between the prefrontal cortex and temporal regions. Two studies have reported that CRT induces changes in gray matter volume in the hippocampus. Further, one study observed that patients who had received CRT had elevated fractional anisotropy in the basal ganglia. We conclude that neuroimaging studies assessing CRT in patients with schizophrenia showed functional, structural, and connectivity changes that were positively correlated with cognitive improvements despite heterogeneous CRT approaches. Future studies that combine multiple modalities are required to address the differences, effects of intrinsic motivation, and pharmacological augmentation of CRT. Further understanding of the biological basis might lead to predictions of the CRT response in patients with schizophrenia and contribute to identification of schizophrenia patients for future interventions.

Exploring Heterogeneity on the Wisconsin Card Sorting Test in Schizophrenia Spectrum Disorders: A Cluster Analytical Investigation

OBJECTIVES

The Wisconsin Card Sorting Test (WCST) is a complex measure of executive function that is frequently employed to investigate the schizophrenia spectrum. The successful completion of the task requires the interaction of multiple intact executive processes, including attention, inhibition, cognitive flexibility, and concept formation. Considerable cognitive heterogeneity exists among the schizophrenia spectrum population, with substantive evidence to support the existence of distinct cognitive phenotypes. The within-group performance heterogeneity of individuals with schizophrenia spectrum disorder (SSD) on the WCST has yet to be investigated. A data-driven cluster analysis was performed to characterise WCST performance heterogeneity.

METHODS

Hierarchical cluster analysis with k-means optimisation was employed to identify homogenous subgroups in a sample of 210 schizophrenia spectrum participants. Emergent clusters were then compared to each other and a group of 194 healthy controls (HC) on WCST performance and demographic/clinical variables.

RESULTS

Three clusters emerged and were validated via altered design iterations. Clusters were deemed to reflect a relatively intact patient subgroup, a moderately impaired patient subgroup, and a severely impaired patient subgroup.

CONCLUSIONS

Considerable within-group heterogeneity exists on the WCST. Identification of subgroups of patients who exhibit homogenous performance on measures of executive functioning may assist in optimising cognitive interventions. Previous associations found using the WCST among schizophrenia spectrum participants should be reappraised. (JINS, 2019, 25, 750-760).

A Randomized Controlled Trial of Executive Functioning Training Compared With Perceptual Training for Schizophrenia Spectrum Disorders: Effects on Neurophysiology, Neurocognition, and Functioning

OBJECTIVE

Cognitive remediation is an efficacious treatment for schizophrenia. However, different theoretical approaches have developed without any studies to directly compare them. This is the first study to compare the two dominant approaches to cognitive remediation (training of executive skills and training of perceptual skills) and employed the broadest assessment battery in the literature to date.

METHODS

Outpatients with schizophrenia spectrum disorders were randomly assigned to receive either executive training or perceptual training. Electrophysiological activity, neurocognition, functional competence, case manager-rated community functioning, clinical symptoms, and self-report measures were assessed at baseline, immediately after treatment, and at a 12-week posttreatment follow-up assessment.

RESULTS

Perceptual training improved the EEG mismatch negativity significantly more than executive training immediately after treatment, although the effect did not persist at the 12-week follow-up. At the follow-up, executive training improved theta power during an n-back task, neurocognition, functional competence, and case manager-rated community functioning to a greater extent than perceptual training. These effects were not observed immediately after treatment.

CONCLUSIONS

Both perceptual training and executive training improved neurophysiological mechanisms specific to their domains of intervention, although only executive training resulted in improvement in neurocognition and functioning. Improvements in favor of executive training did not appear immediately after treatment but emerged 12 weeks after the end of active treatment. Thus, short-term intervention targeting higher-order cognitive functions may prime further cognitive and functional improvement.

An examination of the moderating effects of neurophysiology on treatment outcomes from cognitive training in schizophrenia-spectrum disorders

BACKGROUND

Impairments in neurocognition and community functioning are core features of schizophrenia and cognitive training techniques have been developed with the aim of improving these impairments. While cognitive training has produced reliable improvements in neurocognition and functioning, little is known about factors that moderate treatment response. Electroencephalographic (EEG) measures provide a neurophysiological indicator of cognitive functions that may moderate treatment outcomes from cognitive training.

METHODS

Data from a clinical trial comparing two cognitive training approaches in schizophrenia-spectrum disorders were utilized in the current report. Cluster analysis was conducted to identify participant clusters based on baseline P300, mismatch negativity (MMN), and theta power during an n-back task, and the EEG measures were also examined as continuous predictors of treatment response.

RESULTS

Three clusters were identified based on the baseline EEG variables; however, there were no significant differences in treatment response across the three clusters. Higher P300 amplitude and theta power during the n-back at baseline were significantly associated with greater improvements in a cognitive composite score post-treatment. None of the EEG measures were significantly associated with treatment outcomes in specific cognitive domains or community functioning. Change in EEG measures from baseline to post-treatment was not significantly associated with durability of cognitive or functional change at 12-week follow-up.

CONCLUSIONS

Clusters derived from the EEG measures were not significantly associated with either neurocognitive or functional outcomes. P300 and n-back theta power may be associated with learning-related processes, which are important for acquisition and retention of skills during cognitive training programs. Future research should aim to identify at an individual level who is likely to respond to specific forms of cognitive enhancement.

Three-Year Follow-Up Study Exploring Metacognition and Function in Individuals With First Episode Psychosis

Introduction: Research has demonstrated that functional outcome in psychosis is predicted by factors such as neurocognition, functional capacity, symptoms and, more recently, metacognition. Metacognitive ability has been demonstrated to mediate between neurocognition and functional outcome in First Episode Psychosis (FEP). Whether metacognition also predicts longer-term recovery in first episode psychosis is unknown. This study assessed whether neurocognition, functional capacity and metacognitive ability in FEP predicted functional outcome three years later. Methods: Eighty individuals with First Episode Psychosis were re-contacted after an average 3 years (range: 26-45 month follow-up) from baseline. Twenty-six participants (33%) completed completed measures of neurocognition, metacognition, functional capacity, functional outcome (hours spent in structured activity per week) and psychopathology at baseline and at follow-up. Results: Individual regression analyses demonstrated neurocognition, functional capacity, and metacognitive ability at baseline significantly predicted functional outcome at three years. However, when baseline functional outcome was controlled, only metacognitive ability was a significant predictor of change in functional outcome from baseline to follow-up, p < 0.001. This model explained 72% (adjusted r ² = 0.69) of the variance in functional outcome at follow-up. Negative symptoms did not change the model. Discussion: This study demonstrated that better metacognitive ability significantly predicted improvement in functioning in FEP across a 3-year period. This highlights the potential value of clinical interventions that focus on improving metacognitive ability at first point of illness to maximize recovery.

Brief executive function training for individuals with severe mental illness: Effects on EEG synchronization and executive functioning

BACKGROUND

Executive Functioning (EF) is an important factor for community functioning for people with severe mental illness. Cognitive remediation programs often improve EF, but do so by using multiple therapeutic techniques. Little is known regarding how individual treatment elements promote cognitive improvement. Oscillatory brain activity is a potential neurophysiological mechanism that may change as a result of targeted training on computerized exercises. The current study aimed to examine the effects of a brief EF training program on EEG and neurocognitive measures.

METHODS

25 people with severe mental illness were randomized to either 2weeks of computerized EF training or control training. Training consisted of 1h training sessions 3 times per week and 40min of daily home training. Assessments examined EEG theta and alpha band oscillatory power during EF tasks and neurocognitive measures of EF.

RESULTS

EF training resulted in greater frontal theta power and reduced posterior alpha power during computerized EF tasks than control training. Power in the alpha frequency band over frontal electrode sites did not significantly differ between the two groups as a result of training. Additionally, participants in the EF training experienced significantly greater improvement in EF ability as measured by neurocognitive tests than the control condition.

CONCLUSIONS

Two weeks of EF training is sufficient to produce neurophysiological and neurocognitive change. Frontal theta power and posterior alpha power may be important neurophysiological markers to consider in cognitive remediation studies, and the addition of a brief executive function training procedure to other psychosocial interventions is worth examining.

Exploring the associations of herpes simplex virus infection and cognitive dysfunction in schizophrenia: Studies in India

BACKGROUND

Cognitive dysfunctions being core features of schizophrenia (SZ), cause disability, increase burden and are refractory to treatment. Viral infections are not risk factors for SZ, but growing evidence indicates infection with some neurotropic viruses, particularly Herpes simplex virus type 1 (HSV -1) as a risk factor for cognitive dysfunction.

STUDIES IN INDIA

Three research studies in India are described. In the first, participants were evaluated for HSV-1 infection and cognitive functions (cases 198 and controls 100). In the second, patients and normal nonpsychotic control individuals were examined at baseline and followed up over 1-3 years (cases 138 and controls 88). In the third, a randomized, double-blind placebo-controlled antipsychotic adjunctive trial was conducted to examine the effect of anti-viral drug valacyclovir over 16 weeks on cognitive functioning (valacyclovir 30; placebo 32, treatment for 16 weeks).

RESULTS OF INDIAN STUDIES

Cross-sectional study: HSV-1 infection was associated with modest dysfunction, especially on attention (accuracy) and spatial processing (speed).

LONGITUDINAL STUDY

HSV-1 seropositive participants had lower scores at baseline on 6/16 measures, regardless of SZ diagnoses. At follow-up, there was a significant decline in HSV-1-positive participants for abstraction and mental flexibility and emotion discrimination.

RANDOMIZED CONTROLLED TRIAL

Significantly, greater improvement in accuracy index of emotion discrimination in the valacyclovir-treated versus placebo sample was found.

CONCLUSIONS

Indian studies are consistent with a causative role for HSV-1 in cognitive dysfunction regardless of SZ diagnosis; more rigorous studies of the causal hypothesis are needed, particularly larger randomized controlled trials.

Examining the durability of a hybrid, remote and computer-based cognitive remediation intervention for adolescents with 22q11.2 deletion syndrome

AIM

Schizophrenia and 22q11.2 deletion syndrome (22q11DS) share similar patterns of cognitive deficits. Up to 30% of those with 22q11DS develop schizophrenia during early adulthood. As cognitive decline has recently been found to predict onset of psychosis in adolescents with 22q11DS, early interventions such as cognitive remediation (CR) during adolescence are warranted. This paper investigates the durability of a remote, computerized, CR programme for youth with 22q11DS. Our aim was to determine if the positive effects of CR persisted 6 months beyond intervention completion.

METHODS

A longitudinal design with 21 participants serving as their own controls was used. Youth were seen for neurocognitive assessments at pre-treatment, after the targeted 8-month intervention, at post-treatment, and 6 months after for follow-up. During the intervention, cognitive coaches met remotely with participants for CR via video conferencing three times a week, and offered task-specific strategies. To determine if intervention improvements held across the 6-month follow-up period, neurocognitive measures were statistically examined with repeated measures analysis of variances from pre-treatment through follow-up.

RESULTS

Our CR intervention proved durable. Post-treatment improvements comprising cognitive flexibility, executive function, reaction time and working memory were maintained over the follow-up period.

CONCLUSIONS

Results confirm previous research regarding the durability of CR treatment and extend these findings to youth with 22q11DS. The present study may serve to inform early intervention efforts focused on cognitive and functionally relevant rehabilitation goals for youth with 22q11DS and suggests that 22q11DS can potentially serve as a suitable model for examining the trajectory preceding psychosis.

Barriers to the implementation of a computer-based rehabilitation programme in two public psychiatric settings

Background

Working memory (WM) deficits have a negative impact on treatment adherence and quality of life. Efficient and effective interventions are needed in order to improve the cognitive functioning of those affected, especially in low-resource communities. Computer-based rehabilitation programmes (CBRP) are low-cost therapeutic approaches for WM deficits. Perceptions and experiences of target users may influence whether CBRP constitute an effective therapeutic option for adults with cognitive impairment in under-resourced environments.

Aim

The goal of the study was to explore the experiences of a group of volunteers with WM deficits (associated with diagnoses of HIV and schizophrenia), in terms of the perceived barriers they encountered during their participation in a CBRP.

Methods

A qualitative, descriptive research design was implemented. Short interviews and field notes were used in order to investigate the experiences of nine participants in relation to the CBRP. The sample included four participants living with HIV and five with schizophrenia, all with WM deficits.

Results

Using a thematic analysis, eight barriers were identified: unawareness of the cognitive deficit, anticipation of negative results, stigma, difficulties accessing a computer and/or Internet connection, ill health, negative emotional experiences, daily routine challenges and non-conducive or sabotaging environments. A representational model of these barriers is proposed.

Conclusion

The implementation of a cognitive rehabilitation strategy should not only take into consideration issues of access to particular strategies and materials but should also be preceded by an exploration of how individual and contextual barriers are experienced by the potential users, as these contribute to the risk of dropout.

The neurological examination adapted for neuropsychiatry

The neuropsychiatric examination includes standard neurological and cognitive examination techniques with several additional observations and tasks designed to capture abnormalities common among patients with neuropsychiatric disorders or neurocognitive complaints. Although useful as a screening tool, a single standardized rating scale such as the Mini Mental State Examination (MMSE) or the Montreal Cognitive Assessment (MoCA) is insufficient to establish a neuropsychiatric diagnosis. Extra attention is paid to findings commonly seen in the setting of psychiatric disorders, dementias, movement disorders, or dysfunction of cortical or subcortical structures. Dysmorphic features, dermatologic findings, neurodevelopmental signs, signs of embellishment, and expanded neurocognitive testing are included. The neuropsychiatric clinician utilizes the techniques described in this article to adapt the examination to each patient's situation, choosing the most appropriate techniques to supplement the basic neurological and psychiatric examinations in support of diagnostic hypotheses being considered. The added examination techniques facilitate diagnosis of neurocognitive disorders and enable neuropsychiatric formulation.

The relationship between level of cognitive impairments and functional outcome trajectories in first-episode schizophrenia

Although cognitive impairments are consistently linked to functional outcome in chronic schizophrenia, the relationship remains unclear for patients with first-episode schizophrenia. The objective of this present study was to determine whether there are distinct developmental trajectories for functional outcome in patients with different levels of baseline cognition. The present study has a multi-follow-up design, and includes data from six follow-ups over four years. Assessments were conducted yearly, apart from the first year where assessments were conducted every six months. A total of 28 patients with first-episode schizophrenia participated in the study, with 79% of patients retained at the 4-year follow-up. Cognition was assessed with MATRICS Consensus Cognitive Battery. Functional outcomes were obtained through Global functioning: Social and Global functioning: Role. Data were analyzed with linear multilevel models. Results suggest steady improvements in social and role functioning among the patients across the four year period. Baseline attention, verbal learning, and verbal working memory were significantly associated with social outcome. Role functioning was significantly associated with attention, verbal working memory, and reasoning/problem solving. Furthermore, the rate of change in social outcome varies among patients depending on their baseline level of attention and verbal working memory, with the lowest scoring group showing the least improvement over the years. The subgroup of patients with the largest cognitive impairments at the onset of the disorder shows limited improvements in social functioning compared to higher functioning groups.

Web-Based Cognitive Remediation Improves Supported Employment Outcomes in Severe Mental Illness: Randomized Controlled Trial

BACKGROUND

Finding work is a top priority for most people; however, this goal remains out of reach for the majority of individuals with a severe mental illness (SMI) who remain on benefits or are unemployed. Supported employment (SE) programs aimed at returning people with a severe mental illness to work are successful; however, they still leave a significant number of people with severe mental illness unemployed. Cognitive deficits are commonly found in SMI and are a powerful predictor of poor outcome. Fortunately, these deficits are amenable to treatment with cognitive remediation therapy (CRT) that significantly improves cognition in SMI. CRT combined with SE significantly increases the likelihood of individuals with severe mental illness obtaining and staying in work. However, the availability of CRT is limited in many settings.

OBJECTIVE

The aim of this study was to examine whether Web-based CRT combined with a SE program can improve the rate return to work of people with severe mental illness.

METHODS

A total of 86 people with severe mental illness (mean age 39.6 years; male: n=55) who were unemployed and who had joined a SE program were randomized to either a Web-based CRT program (CogRem) or an Internet-based control condition (WebInfo). Primary outcome measured was hours worked over 6 months post treatment.

RESULTS

At 6 months, those participants randomized to CogRem had worked significantly more hours (P=.01) and had earned significantly more money (P=.03) than those participants randomized to the WebInfo control condition. No change was observed in cognition.

CONCLUSIONS

This study corroborates other work that has found a synergistic effect of combining CRT with a SE program and extends this to the use of Web-based CRT. The lack of any improvement in cognition obscures the mechanism by which an improved wage outcome for participants randomized to the active treatment was achieved. However, the study substantially lowers the barrier to the deployment of CRT with other psychosocial interventions for severe mental illness.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ANZCTR) 12611000849998; http://www.anzctr.org.au/TrialSearch.aspx?searchTxt=12611000849998&isBasic=True (Archived by WebCite at http://www.webcitation.org/6sMKwpeos).

Understanding access and use of technology among youth with first-episode psychosis to inform the development of technology-enabled therapeutic interventions

AIM

Computers, video games and technological devices are part of young people's everyday lives. However, their use in first-episode psychosis (FEP) treatment is rare. The purpose of this study was to better understand the access and use of technology among individuals with FEP, including gaming activities, to inform future development of technology-enabled therapeutic applications.

METHODS

Self-administered survey on use of technological tools in 71 FEP individuals.

RESULTS

PCs/laptops were used by all participants; cellphones/smartphones by 92%, consoles by 83% (mainly male and younger participants). Women texted and used social networks more frequently; men played games (mainly action) more often. The younger individuals reported playing games frequently (32% daily) with less use of the Web and social networks (favourite: Facebook).

CONCLUSIONS

These data will be useful for developing Web-based psychoeducation tools and cognitive remediation video games for youth with FEP.

Occupational Performance of People Diagnosed with Schizophrenia in Supported Housing and Outreach Programmes in Australia

This study compared the occupational performance in activities of daily living (ADL) of people diagnosed with schizophrenia in two settings: 25 people in residential rehabilitation facilities and 18 people receiving intensive outreach support in their homes in urban Australia. All participants were assessed with structured interviews, the Assessment of Motor and Process Skills (a performance-based measure of ADL ability) and the Life Skills Profile (an informant-report measure of disability).

Hypothesised differences in ADL performance between the two settings were not supported. Mean ADL process ability, based on the AMPS process skills subscale, indicated that the majority (58%) of the 43 participants needed some assistance in community living, irrespective of where they lived and the types of support received. Many participants (42%) performed ADL tasks with relative ease, efficiency, safety and independence as measured by AMPS, indicating that they could live in housing arrangements with outreach support. However, the ADL process ability measures for two-thirds of these participants indicated that they would struggle in community living in the absence of outreach support.

Given these findings, the eligibility criteria and screening for residential and outreach support services need re-examination and performance-based assessments of ADL ability could improve the identification of housing-related support needs. Occupational therapists have expertise in this area to develop individualised supports that enable a greater choice of living arrangements for people diagnosed with schizophrenia.

Integrating Scale Data and Patient Perspectives for Assessing Functionality in Schizophrenia

There is a growing body of literature devoted to evaluating functionality when planning the psychosocial rehabilitation of patients with schizophrenia. Until recently, psychological scales have been the predominant source of information, whereas patients' perceptions about the most disruptive limitations on their daily life were not considered. The aim of this paper is to illustrate how the integration of the perspectives of patients and patients' relatives improves the evaluation of functionality. A QUAN + QUAL design was implemented collecting quantitative data from Family APGAR and BELS scales, and qualitative information by conducting focus groups. The integration of results made it possible to understand the causes of problems reported by scales, as well as improving the information captured for helping to plan patient therapies. This mixed approach has provided a more comprehensive perspective of functionality, which will be helpful in improving quality of life of patients and their relatives.

An optimal combination of MCCB and CANTAB to assess functional capacity in older individuals with schizophrenia

INTRODUCTION

Cognitive deficits predict functional capacity in patients with schizophrenia including in late life. The MATRICS Consensus Cognitive Battery (MCCB) and the Cambridge Neuropsychological Test Automated Battery (CANTAB) are widely used to assess cognition in this population. The aim of this study was to determine a minimal set of subtests across the two batteries that would be strongly associated with functional capacity in older patients with schizophrenia.

METHODS

Sixty participants age 50 years or older with a diagnosis of schizophrenia or schizoaffective disorder and 30 control participants were enrolled. Cognition was assessed using the MCCB and the CANTAB. Functional capacity was assessed using the USCD Performance-based Skills Assessment (UPSA). Stepwise linear regressions were performed to determine the best set of cognitive tests associated with functional capacity.

RESULTS

UPSA total score was negatively correlated with age and positively correlated with education and the MCCB global score. Most of the MCCB domains and subtests, and several of the CANTAB subtests correlated with UPSA total score. In the regression model, MCCB global score accounted for 42.5% of UPSA variance. In contrast, a combination of only four subtests (processing speed and verbal learning from the MCCB, and affective information processing and working memory from the CANTAB) accounted for 60% of UPSA variance.

CONCLUSIONS

Performance on MCCB and CANTAB is strongly associated with functional capacity in older patients with schizophrenia. A selective combination of MCCB and CANTAB subtests may be as effective in assessing functional capacity in late life schizophrenia. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

FDG-PET scans in patients with Kraepelinian and non-Kraepelinian schizophrenia

We recruited 14 unmedicated patients with Kraepelinian schizophrenia (12 men and 2 women; mean age = 47 years old), 27 non-Kraepelinian patients (21 men and 6 women; mean age = 36.4 years old) and a group of 56 age- and sex-matched healthy volunteers. FDG positron emission tomography and MRI scans were coregistered for both voxel-by-voxel statistical mapping and stereotaxic regions of interest analysis. While both Kraepelinian and non-Kraepelinian patients showed equally lower uptake than healthy volunteers in the frontal lobe, the temporal lobes (Brodmann areas 20 and 21) showed significantly greater decreases in Kraepelinian than in non-Kraepelinian patients. Kraepelinian patients had lower FDG uptake in parietal regions 39 and 40, especially in the right hemisphere, while non-Kraepelinian patients had similar reductions in the left. Only non-Kraepelinian patients had lower caudate FDG uptake than healthy volunteers. While both patient groups had lower uptake than healthy volunteers in the medial dorsal nucleus of the thalamus, Kraepelinian patients alone had higher uptake in the ventral nuclei of the thalamus. Kraepelinian patients also showed higher metabolic rates in white matter. Our results are consistent with other studies indicating that Kraepelinian schizophrenia is a subgroup of schizophrenia, characterized by temporal and right parietal deficits and normal rather than reduced caudate uptake. It suggests that Kraepelinian schizophrenia may be more primarily characterized by FDG uptake decreased in both the frontal and temporal lobes, while non-Kraepelinian schizophrenia may have deficits more limited to the frontal lobe. This is consistent with some neuropsychological and prognosis reports of disordered sensory information processing in Kraepelinian schizophrenia in addition to deficits in frontal lobe executive functions shared with the non-Kraepelinian subtype.

Cognitive remediation in schizophrenia-The view from India

The prevalence and disability due to Schizophrenia (SZ) in India is similar to other parts of the world. Cognitive impairments are also present in a large group of Indian persons with SZ. Interventions to address these impairments - termed cognitive remediation or cognitive retraining - are being tested all over the world. Indian research on remediation in schizophrenia has been eclectic and is reviewed here. Some investigators have focused mainly on symptom control and quality of life, as yoga could be a cost effective and culturally acceptable intervention for remediation and rehabilitation. Although participants were not exhaustively tested for improvement in cognitive function in the majority of such trials, published results are encouraging.

Participation in daily life of people with schizophrenia in comparison to the general population

Background.

Participation in occupations is a basic human right. Although people with schizophrenia commonly experience restrictions in participation, there is a paucity of research in this area.

Purpose.

This study aimed to compare the participation patterns of people with schizophrenia to people without mental illness (control group).

Method.

A total of 140 people of similar age and sex completed the Adults Subjective Assessment of Participation and provided demographic and health-related data.

Findings.

People with schizophrenia tend to participate in fewer activities and to participate alone. However, they participate with similar intensity as those in the control group.

Implications.

The participation patterns of people with schizophrenia are both unique and similar to those of the general population. The differences in participation raise concerns due to signs of restriction and social exclusion. However, it appears that people with schizophrenia benefit from occupation and community-based services that promote and support participation with others in diverse activities.

Methodological issues associated with preclinical drug development and increased placebo effects in schizophrenia clinical trials

Recent failures to detect efficacy in clinical trials investigating pharmacological treatments for schizophrenia raise concerns regarding the potential contribution of methodological shortcomings to this research. This review provides an examination of two key methodological issues currently suspected of playing a role in hampering schizophrenia drug development; 1) limitations on the translational utility of preclinical development models, and 2) methodological challenges posed by increased placebo effects. Recommendations for strategies to address these methodological issues are addressed.

Cluster analysis differentiates high and low community functioning in schizophrenia: Subgroups differ on working memory but not other neurocognitive domains

BACKGROUND

Schizophrenia is characterized by impairment in multiple aspects of community functioning. Available literature suggests that community functioning may be enhanced through cognitive remediation, however, evidence is limited regarding whether specific neurocognitive domains may be treatment targets. We characterized schizophrenia subjects based on their level of community functioning through cluster analysis in an effort to identify whether specific neurocognitive domains were associated with variation in functioning.

METHODS

Schizophrenia (SCZ, n=60) and control (CON, n=45) subjects completed a functional capacity task, social competence role-play, functional attainment interview, and a neuropsychological battery. Multiple cluster analytic techniques were used on the measures of functioning in the schizophrenia subjects to generate functionally-defined subgroups. MANOVA evaluated between-group differences in neurocognition.

RESULTS

The cluster analysis revealed two distinct groups, consisting of 36 SCZ characterized by high levels of community functioning (HF-SCZ) and 24 SCZ with low levels of community functioning (LF-SCZ). There was a main group effect for neurocognitive performance (p<0.001) with CON outperforming both SCZ groups in all neurocognitive domains. Post-hoc tests revealed that HF-SCZ had higher verbal working memory compared to LF-SCZ (p≤0.05, Cohen's d=0.78) but the two groups did not differ in remaining domains.

CONCLUSION

The cluster analysis classified schizophrenia subjects in HF-SCZ and LF-SCZ using a multidimensional assessment of community functioning. Moreover, HF-SCZ demonstrated rather preserved verbal working memory relative to LF-SCZ. The results suggest that verbal working memory may play a critical role in community functioning, and is a potential cognitive treatment target for schizophrenia subjects.

A randomized pilot study of MOtiVation and Enhancement (MOVE) Training for negative symptoms in schizophrenia

INTRODUCTION

Among individuals with schizophrenia, those who have persistent and clinically significant negative symptoms (PNS) have the poorest functional outcomes and quality of life. The NIMH-MATRICS Consensus Statement indicated that these symptoms represent an unmet therapeutic need for large numbers of individuals with schizophrenia. No psychosocial treatment model addresses the entire constellation of PNS.

METHOD

51 patients with PNS were randomized into one of two groups for a period of 9 months: 1) MOtiVation and Enhancement (MOVE) or 2) treatment as usual. MOVE is a home based, manual-driven, multi-modal treatment that employs a number of cognitive and behavioral principles to address the broad range of factors contributing to PNS and their functional consequences. The components of MOVE include: Environmental supports to prompt initiation and persistence, in-vivo skills training to ameliorate deficits and encourage interaction, cognitive behavioral techniques to address self-defeating attitudes, in-vivo training in emotional processing to address affective blunting and problems in identifying emotions, and specific techniques to address the deficits in anticipatory pleasure. Patients were assessed at baseline and each 3 months with multiple measures of negative symptoms.

RESULTS

Repeated measures analyses of variance for mixed models indicated significant Group by Time effects for the Negative Symptom Assessment (NSA; p<.02) and the Clinical Assessment Interview for Negative Symptoms (CAINS; p<.04). Group differences were not significant until 9 months of treatment and were not significant for the Brief Negative Symptom Scale (BNSS).

CONCLUSION

Further investigation of a comprehensive treatment for PNS, such as MOVE, is warranted.

Drift diffusion model of reward and punishment learning in schizophrenia: Modeling and experimental data

In this study, we tested reward- and punishment learning performance using a probabilistic classification learning task in patients with schizophrenia (n=37) and healthy controls (n=48). We also fit subjects' data using a Drift Diffusion Model (DDM) of simple decisions to investigate which components of the decision process differ between patients and controls. Modeling results show between-group differences in multiple components of the decision process. Specifically, patients had slower motor/encoding time, higher response caution (favoring accuracy over speed), and a deficit in classification learning for punishment, but not reward, trials. The results suggest that patients with schizophrenia adopt a compensatory strategy of favoring accuracy over speed to improve performance, yet still show signs of a deficit in learning based on negative feedback. Our data highlights the importance of applying fitting models (particularly drift diffusion models) to behavioral data. The implications of these findings are discussed relative to theories of schizophrenia and cognitive processing.

From hospital admission to independent living: is prediction possible?

An integral component of recovery from mental illness is being able to engage in everyday activities. This ability is often restricted among people with schizophrenia. Although functional deficits are addressed during hospitalization, the ability to predict daily functioning based on information gathered during hospitalization has not been well established. This study examines whether measurements completed during hospitalization can be useful for predicting independent living within the community. Inpatients with schizophrenia (N=104) were enrolled in the study and assessed for cognitive functioning, functional capacity and symptoms. They were approached again 6 months after discharge to evaluate their functioning with respect to everyday life Instrumental Activities of Daily Living (IADL) and Activities of Daily Living (ADL). Functional capacity during hospitalization predicted 26.8% of ADL functioning and 38.8% of IADL functioning. ADL was best predicted by the severity of negative symptoms, cognitive functioning, and the number of hospitalizations (51.2%), while IADL was best predicted by functional capacity, cognition, and number of hospitalizations (60.1%). This study provides evidence that evaluations during hospitalization can be effective, and demonstrates the advantage of a holistic approach in predicting daily functioning. When a holistic approach is not practical, a functional capacity measurement may serve as an effective predictor.

From Theory to PrACTice: A Cognitive Remediation Program Based on a Neuropsychological Model of Schizophrenia

Cognitive dysfunction is one of the hallmark deficits of schizophrenia. A wide range of studies illustrate how it is strongly interconnected to clinical presentation and daily life functioning [see Ref. (1, 2)]. Hence, cognition is an important treatment target in schizophrenia. To address the challenge of cognitive enhancement in schizophrenia, a large number of cognitive remediation programs have been developed and evaluated over the past several decades. First, an overview of these programs is presented highlighting their specificity to cognitive deficit in schizophrenia using an integrated method. In this case, cognitive training focuses on enhancing several elementary cognitive functions considered as a prerequisite to social skills or vocational training modules. These programs are based on the neurodevelopmental hypothesis of schizophrenia. However, moderate improvement for patients who benefit from these therapies has been observed as described in Wykes et al. review (3). Next, neuropsychological models of schizophrenia are then presented. They highlight the critical role of the internally generated intentions in appropriate willful actions. The cognitive control mechanism deals with this ability. Interestingly, available cognitive remediation programs have not been influenced by these models. Hence, we propose another alternative to set up a specific cognitive remediation program for schizophrenia patients by targeting the cognitive control mechanism. We describe the PrACTice program that is in the process of being validated.

Metamemory with ageing in schizophrenia: a first study

The aim was to study metamemory during encoding in older schizophrenia patients. Thirteen older patients were compared to 13 healthy controls. Despite their memory impairment, older schizophrenia patients were able to assess the material accurately. They were not able, however, to adapt their learning time as efficiently as controls.

Antidepressants for cognitive impairment in schizophrenia--a systematic review and meta-analysis

BACKGROUND

Cognitive impairment in schizophrenia is disabling, but current treatment options remain limited.

OBJECTIVE

To meta-analyze the efficacy and safety of adjunctive antidepressants for cognitive impairment in schizophrenia.

DATA SOURCES AND STUDY SELECTION

PubMed, MEDLINE, PsycINFO, and Cochrane Library databases were searched until 12/2013 for randomized controlled trials comparing antidepressant augmentation of antipsychotics with placebo regarding effects on cognitive functioning in schizophrenia.

DATA EXTRACTION

Two authors independently extracted data. Standardized mean differences (SMDs) were calculated for continuous outcomes and risk ratios for categorical outcomes. SMDs of individual cognitive tests were pooled on a study level within domains (primary outcome) and across domains. When results were heterogeneous, random instead of fixed effects models were used.

RESULTS

We meta-analyzed 11 studies (duration = 8.7 ± 3.7 weeks) including 568 patients (mean age = 39.5 ± 6.9 years, males = 67.2%, illness duration = 12.5 ± 8.0 years). Antidepressants included mirtazapine (4 studies; n = 126), citalopram (2 studies; n = 231), fluvoxamine (1 study; n = 47), duloxetine (1 study; n = 40), mianserin (1 study; n = 30), bupropion (1 study; n = 61), and reboxetine (1 study; n = 33). Statistically significant, but clinically negligible, advantages were found for pooled antidepressants compared to placebo in executive function (Hedges' g = 0.17, p = 0.02) and a composite cognition score (Hedges' g = 0.095, p = 0.012). Depression improved with serotonergic antidepressants (p = 0.0009) and selective serotonin reuptake inhibitors (p = 0.009), but not with pooled antidepressants (p = 0.39). Sedation was more common with pooled antidepressants (p = 0.04).

CONCLUSION

Adjunctive antidepressants do not demonstrate clinically significant effects on cognition in schizophrenia patients, however, larger studies, preferably in euthymic schizophrenia patients and using full neurocognitive batteries, are needed to confirm this finding.

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.

Multitasking capacities in persons diagnosed with schizophrenia: a preliminary examination of their neurocognitive underpinnings and ability to predict real world functioning

Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia and in particular during multitasking activities. However, at present, patients׳ multitasking capacities have not been adequately examined in the literature due to the absence of suitable assessment strategies. We thus recently developed a computerized real-life activity task designed to take into account the complex and multitasking nature of certain everyday life activities where participants are required to prepare a room for a meeting. Twenty-one individuals diagnosed with schizophrenia and 20 matched healthy controls completed the computerized task. Patients were also evaluated with a cognitive battery, measures of symptomatology and real world functioning. To examine the ecological validity, 14 other patients were recruited and were given the computerized version and a real version of the meeting preparation task. Results showed that performance on the computerized task was significantly correlated with executive functioning, pointing to the major implication of these cognitive processes in multitasking situations. Performance on the computerized task also significantly predicted up to 50% of real world functioning. Moreover, the computerized task demonstrated good ecological validity. These findings suggest the importance of evaluating multitasking capacities in patients diagnosed with schizophrenia in order to predict real world functioning.

Preserved strategic grain-size regulation in memory reporting in patients with schizophrenia

BACKGROUND

Cognitive and introspection disturbances are considered core features of schizophrenia. In real life, people are usually free to choose which aspects of an event they recall, how much detail to volunteer, and what degree of confidence to impart. Their decision will depend on various situational and personal goals. The authors explored whether schizophrenia patients are able to achieve a compromise between accuracy and informativeness when reporting semantic information.

METHODS

Twenty-five patients and 23 healthy matched control subjects answered general knowledge questions requiring numerical answers (how high is the Eiffel tower?), freely at first and then through a metamemory-based control. In the second phase, they answered with respect to two predefined intervals, one narrow and one broad; attributed a confidence judgment to both answers; and afterward selected one of the two answers. Data were analyzed using analyses of variance with group as the between-subjects factor.

RESULTS

Patients reported information at a self-paced level of precision less accurately than healthy participants. However, they benefited remarkably from the framing of the response and from the metamemory processes of monitoring and control to the point of improving their memory reporting and matching healthy subjects' accuracy.

CONCLUSIONS

In spite of their memory deficit during free reporting, after accuracy monitoring, patients strategically regulated the grain size of their memory reporting and proved able to manage the competing goals of accuracy and informativeness. These results give some cause for optimism as to the possibility for patients to adapt to everyday life situations.

Performance-based empathy mediates the influence of working memory on social competence in schizophrenia

Empathic deficits have been linked to poor functioning in schizophrenia, but this work is mostly limited to self-report data. This study examined whether performance-based empathy measures account for incremental variance in social competence and social attainment above and beyond self-reported empathy, neurocognition, and clinical symptoms. Given the importance of working memory in theoretical models of empathy and in the prediction of functioning in schizophrenia, we also examined whether empathy mediates the relationship between working memory and functioning. Sixty outpatients and 45 healthy controls were compared on performance-based measures of 3 key components of empathic responding, including facial affect perception, emotional empathy (affective responsiveness), and cognitive empathy (emotional perspective-taking). Participants also completed measures of self-reported empathy, neurocognition, clinical symptoms, and social competence and attainment. Patients demonstrated lower accuracy than controls across the 3 performance-based empathy measures. Among patients, these measures showed minimal relations to self-reported empathy but significantly correlated with working memory and other neurocognitive functions as well as symptom levels. Furthermore, cognitive empathy explained significant incremental variance in social competence (∆R (2) = .07, P < .05) and was found to mediate the relation between working memory and social competence. Performance-based measures of empathy were sensitive to functionally relevant disturbances in schizophrenia. Working memory deficits appear to have an important effect on these disruptions in empathy. Empathy is emerging as a promising new area for social cognitive research and for novel recovery-oriented treatment development.

Predictive validity of a MK-801-induced cognitive impairment model in mice: implications on the potential limitations and challenges of modeling cognitive impairment associated with schizophrenia preclinically

Cognitive impairment associated with schizophrenia (CIAS) is a major and disabling symptom domain of the disease that is generally unresponsive to current pharmacotherapies. Critically important to the discovery of novel therapeutics for CIAS is the utilization of preclinical models with robust predictive validity. We investigated the predictive validity of MK-801-induced memory impairments in mouse inhibitory avoidance (MK-IA) as a preclinical model for CIAS by investigating compounds that have been tested in humans, including antipsychotics, sodium channel blocker mood stabilizers, and putative cognitive enhancers. The atypical antipsychotic clozapine, as well as risperidone and olanzapine (see Brown et al., 2013), had no effect on MK-801-induced memory impairments. For sodium channel blockers, carbamazepine significantly attenuated memory impairments induced by MK-801, whereas lamotrigine had no effect. Nicotine, donepezil, modafinil, and xanomeline all significantly attenuated MK-801-induced memory impairments, but the magnitude of effects and the dose-responses observed varied across compounds. Clinically, only acute administration of nicotine has demonstrated consistent positive effects on CIAS, while inconsistent results have been reported for lamotrigine, donepezil, and modafinil; atypical antipsychotics produce only moderate improvements at best. A positive clinical signal has been observed with xanomeline, but only in a small pilot trial. The results presented here suggest that the MK-IA model lacks robust predictive validity for CIAS as the model is likely permissive and may indicate false positive signals for compounds and mechanisms that lack clear clinical efficacy for CIAS. Our findings also highlight the potential limitations and challenges of using NMDA receptor antagonists in rodents to model CIAS.

Benefits and limits of anticholinergic use in schizophrenia: focusing on its effect on cognitive function

All currently available antipsychotic drugs are the dopamine D2 receptor antagonists and are capable of producing extrapyramidal side-effects (EPS). Anticholinergic drugs are primarily used to treat EPS or prevent EPS induced by antipsychotics in the treatment of psychosis and schizophrenia. However, they can cause a variety of distressing peripheral side-effects (e.g. dry mouth, urinary disturbances, and constipation) and central adverse effects (e.g. cognitive impairment, worsening of tardive dyskinesia, and delirium). Disturbances in cognitive abilities are cardinal features of schizophrenia from its earliest phases and account for much of the functional disability associated with the illness. It is likely that long-term concomitant administration of anticholinergics exacerbates the underlying cognitive impairment in patients with schizophrenia and subsequently affects patients' quality of life. Thus, current treatment guidelines for schizophrenia generally do not recommend the prophylactic and long-term use of anticholinergics. However, the high use of long-term anticholinergic drugs with antipsychotics has been identified as an important issue in the treatment of schizophrenia in several countries. To assess the benefits and limits of anticholinergic use in psychosis and schizophrenia, this article will provide a brief review of the pharmacology and clinical profiles of anticholinergic drugs and will focus on their effects on cognitive function in schizophrenia, particularly during the course of the early phase of the illness. In addition, we will address the effects of discontinuation of anticholinergics on cognitive function in patients with schizophrenia and provide a strategy for adjunctive anticholinergic use in patients treated with long-acting injectable antipsychotics.

Neurocognitive functioning in patients with first-episode schizophrenia 1 year from onset in comparison with patients 5 years from onset

OBJECTIVE

The course of neurocognitive deficits in schizophrenia has not yet been established. Therefore, we followed patients with first-episode schizophrenia to verify the course of these deficits.

METHODS

In Study 1, tests of neurocognitive functioning were administered to patients with first-episode schizophrenia (FE group) every 6 months. Of the 26 patients who completed the baseline assessment, 19 completed a 6-month follow-up, and 13 completed a 1-year follow-up. In Study 2, 19 patients in FE group at 6-months when the neuropsychological measures was less influenced by psychotic symptoms and other patients who experienced schizophrenia 5-years earlier (5-year group) were compared.

RESULTS

In Study 1, verbal memory, motor speed, and executive functions significantly improved at the 1-year follow-up. In Study 2, patients in 5-year group performed worse in verbal memory and executive functions than patients in FE at 6-month group, but marginally but significantly better in verbal fluency.

CONCLUSIONS

Verbal memory, executive functions, and verbal fluency were significantly different between 5-year group and FE at 6-month group, and may indicate progression of schizophrenia. Executive functions may reflect the state of psychosis. Working memory and processing speed which did not change significantly from onset are needed to verify the course in further research.