Verbal memory deficit in patients with schizophrenia: an important future target for treatment

Verbal memory impairments in mood disorders and psychotic disorders: A systematic review of comparative studies

BACKGROUND

Mood and psychotic disorders are both associated with verbal memory impairments. Verbal memory represents an important treatment target for both disorders. However, whether the neurocognitive and neurophysiological profiles of verbal memory impairments differ between specific disorders within these two diagnostic categories and healthy controls remains unclear. The current systematic review synthesized findings from comparative studies which used behavioural and neuroimaging tasks to investigate verbal memory impairments between: (1) mood disorder, psychotic disorder, and healthy control groups; and (2) mood disorder without psychotic features, mood disorder with psychotic features, and healthy control groups.

METHODS

The search strategy combined terms related to three main concepts: 'mood disorders', 'psychotic disorders', and 'verbal memory'. Searches were executed in Embase, MEDLINE, PsycInfo, and PubMed databases. A total of 38 articles met the full eligibility criteria and were included in the final narrative synthesis. Findings were stratified by memory domain (overall composite score, verbal working memory, immediate recall, delayed recall, and recognition memory) and by illness phase (acute and non-acute).

RESULTS

Mood and psychotic disorders displayed consistent verbal memory impairments compared to healthy controls during the acute and non-acute phases. Few significant differences were identified in the literature between mood and psychotic disorders, and between mood disorders with and without psychotic features. Individuals with schizophrenia were found to have decreased immediate and delayed verbal recall performance compared to bipolar disorder groups during the acute phase. Major depressive disorder groups with psychotic features were also found to have decreased delayed verbal recall performance compared to those without psychosis during the acute phase. No consistent differences were identified between mood and psychotic disorders during the non-acute phase. Finally, preliminary evidence suggests there may be functional abnormalities in important frontal and temporal brain regions related to verbal memory difficulties in both mood and psychotic disorders.

DISCUSSION

The current findings have potential implications for the diagnosis and treatment of cognitive impairments in mood and psychotic disorders. Verbal recall memory may serve as a sensitive tool in the risk stratification of cognitive impairments for certain mood and psychotic disorders. Moreover, since no widespread differences between clinical groups were identified, the evidence supports providing targeted interventions for verbal memory, such as pharmacological and non-pharmacological interventions, through a trans-diagnostic approach in mood and psychotic disorders.

Childhood Maltreatment and Its Association with Cognitive Ability in Young People Suspected to Be at Clinical High Risk of Psychosis

INTRODUCTION

Childhood maltreatment is associated with both reduced cognitive functioning and the development of psychotic symptoms. However, the specific relationship between childhood maltreatment, cognitive abilities and (pre)psychotic symptoms remains unclear. Therefore, the aim of this study was to investigate the association between childhood maltreatment and tasks of verbal memory and processing speed in a help-seeking sample of an early detection of psychosis service.

METHODS

A total of 274 participants consisting of 177 clinical high risk (CHR) for psychosis subjects and 97 clinical controls (CC) with subthreshold CHR underwent a battery of neurocognitive assessments measuring the latent variables verbal memory and processing speed. Additionally, the Trauma and Distress Scale (TADS) was administered to assess varying childhood maltreatment subtypes. Structural equation modeling (SEM) was used to examine associations between verbal memory, processing speed, and maltreatment subtypes. Other factors in the model were age, gender, clinical group (CHR or CC), and the presence of different CHR criteria.

RESULTS

Physical abuse was associated with lower scores in verbal memory and processing speed. The explained variance in the SEM reached up to 9.5% for verbal memory and 24.9% for processing speed. Both latent variables were each associated with the presence of cognitive-perceptive basic symptoms. Lower verbal memory was additionally associated with the clinical high-risk group, and processing speed capacity was associated with higher age and female gender.

CONCLUSION

Childhood physical abuse in particular was associated with poorer performance on verbal memory and processing speed across both groups of CHR and CC with subthreshold CHR symptoms. This adds to the current literature on reduced cognitive abilities when childhood maltreatment had occurred, albeit subtype dependent. Our findings, together with high prevalence rates of childhood maltreatment in patients with psychosis or CHR states, along with the presence of cognitive deficits in these patients, highlight the importance of not only assessing cognition but also childhood maltreatment in managing these patients. Future research should investigate the specific biological mechanisms of childhood maltreatment on verbal memory and processing speed in CHR subjects, as neurobiological alterations might explain the underlying mechanisms.

Social withdrawal and neurocognitive correlates in schizophrenia

Poor neurocognitive performance has been associated with poor functional outcome in schizophrenia (SCZ) in past studies. Nonetheless, the likely association between neurocognition and social withdrawal has never been investigated. The aim of our study was to investigate in a large and heterogeneous sample of SCZ patient cross-sectional associations between neurocognitive domains and social withdrawal. The sample included 761 SCZ patients who completed the baseline visit in the CATIE study. Neurocognition was assessed by a comprehensive battery of tests resulting in five domain scores and a composite score. Social withdrawal was measured by a specific item of the Heinrichs-Carpenter Quality of Life Scale. Social withdrawal was associated with a lower score in the neurocognitive composite score and in 'Verbal memory,' 'Processing speed' and 'Working memory' scores. 'Verbal memory' score showed the strongest association with social withdrawal. Eight percent of the total variance of social withdrawal was explained by these three cognitive domains and additional clinical and sociodemographic factors (education years, PANSS positive symptoms score, and employment). Our results confirmed the wide heterogeneity and specificity of the correlation between neurocognitive domains and indicators of functional outcome in SCZ, underlining the role of certain neurocognitive abilities in social withdrawal.

Treatment-resistant schizophrenia: Addressing white matter integrity, intracortical glutamate levels, clinical and cognitive profiles between early- and adult-onset patients

BACKGROUND

Treatment-resistance in schizophrenia is 30-40%. Its neurobiology remains unclear; to explore it, we conducted a combined spectrometry/tractography/cognitive battery and psychopathological rating study on patients with treatment-resistant schizophrenia (TRS), dividing the sample into early-onset (N = 21) and adult-onset TRS (N = 20). Previous studies did not differentiate between early- (onset 13-18 years) and adult-onset (>18 years at formal diagnosis of schizophrenia) TRS.

METHODS

We evaluated cross-sectionally 41 TRS patients (26 male and 15 female) and 20 matched healthy controls (HCs) with psychopathological and cognitive testing prior to participating in brain imaging scanning using magnetic resonance spectroscopy and diffusion tensor imaging to determine the relationship between their symptoms and their glutamate levels and white matter integrity.

RESULTS

TRS patients scored lower than HCs on all cognitive domains; early-onset patients performed better than adult-onset patients only on the Symbol Coding domain. TRS correlated with symptom severity, especially negative symptoms. Glutamate levels and glutamate/creatine were increased in anterior cingulate cortex. Diffusion tensor imaging showed low fractional anisotropy in TRS patients in specific white matter tracts compared to HCs (bilateral anterior thalamic radiation, cortico-spinal tract, forceps minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, and right uncinate fasciculus).

CONCLUSIONS

We identified specific magnetic resonance spectroscopy and diffusion tensor imaging alterations in TRS patients. Adult-onset TRS differed little from early-onset TRS on most measures; this points to alterations being present since the outset of schizophrenia and may constitute a biological signature of treatment-resistance.

Cross-sectional study comparing cognitive function in treatment responsive versus treatment non-responsive schizophrenia: evidence from the STRATA study

BACKGROUND

70%-84% of individuals with antipsychotic treatment resistance show non-response from the first episode. Emerging cross-sectional evidence comparing cognitive profiles in treatment resistant schizophrenia to treatment-responsive schizophrenia has indicated that verbal memory and language functions may be more impaired in treatment resistance. We sought to confirm this finding by comparing cognitive performance between antipsychotic non-responders (NR) and responders (R) using a brief cognitive battery for schizophrenia, with a primary focus on verbal tasks compared against other measures of cognition.

DESIGN

Cross-sectional.

SETTING

This cross-sectional study recruited antipsychotic treatment R and antipsychotic NR across four UK sites. Cognitive performance was assessed using the Brief Assessment of Cognition in Schizophrenia (BACS).

PARTICIPANTS

One hundred and six participants aged 18-65 years with a diagnosis of schizophrenia or schizophreniform disorder were recruited according to their treatment response, with 52 NR and 54 R cases.

OUTCOMES

Composite and subscale scores of cognitive performance on the BACS. Group (R vs NR) differences in cognitive scores were investigated using univariable and multivariable linear regressions adjusted for age, gender and illness duration.

RESULTS

Univariable regression models observed no significant differences between R and NR groups on any measure of the BACS, including verbal memory (ß=-1.99, 95% CI -6.63 to 2.66, p=0.398) and verbal fluency (ß=1.23, 95% CI -2.46 to 4.91, p=0.510). This pattern of findings was consistent in multivariable models.

CONCLUSIONS

The lack of group difference in cognition in our sample is likely due to a lack of clinical distinction between our groups. Future investigations should aim to use machine learning methods using longitudinal first episode samples to identify responder subtypes within schizophrenia, and how cognitive factors may interact within this.

TRAIL REGISTRATION NUMBER

REC: 15/LO/0038.

High-intensity interval training and active video gaming improve neurocognition in schizophrenia: a randomized controlled trial

There is a need for treatments targeting neurocognitive dysfunctions in schizophrenia. The aim of this study was to investigate the neurocognitive effect of aerobic high-intensity interval training (HIIT). A comparison group performed sport simulating active video gaming (AVG). We anticipated that HIIT would improve neurocognition beyond any effect of AVG, due to engagement in higher intensity cardiorespiratory demands. Recent research on the beneficial neurocognitive effect of AVG challenges this expectation but added new relevance to comparing the two interventions. This is an observer-blinded randomized controlled trial. Eighty-two outpatients diagnosed with schizophrenia were allocated to HIIT (n = 43) or AVG (n = 39). Both groups received two supervised sessions per week for 12 weeks. The attrition rate was 31%, and 65% of the participants were defined as protocol compliant study completers. Intention-to-treat analyses showed significant improvements in the neurocognitive composite score from baseline to post-intervention and from baseline to 4 months follow-up in the total sample. The same pattern of results was found in several subdomains. Contrary to our hypothesis, we found no interaction effects of time and group, indicating equal effects in both groups. Separate within-group analysis unexpectedly showed trends of differential effects in the learning domain, as HIIT showed post-intervention improvement in verbal but not visual learning, while AVG showed improvement in visual but not verbal learning. HIIT and AVG improve neurocognition equally, suggesting that both interventions may be applied to target neurocognition in schizophrenia. Future research should investigate trends towards possible differential effects of exercise modes on neurocognitive subdomains. NCT02205684, 31.07.14.

Effects of Tobacco Smoking Status on Verbal Learning and Memory in Patients With Schizophrenia and Non-Psychiatric Controls

BACKGROUND AND OBJECTIVES

Patients with schizophrenia have higher rates of tobacco smoking compared to the general population. Moreover, these patients have deficits in cognition, including verbal learning and memory. However, it is not clear whether smoking status alters verbal learning and memory in schizophrenia. We examined the effects of smoking abstinence and reinstatement on verbal learning and memory in people with schizophrenia and nonpsychiatric controls and other cognitive domains as exploratory.

METHODS

Smoking participants (N = 28; 14 schizophrenia smokers; 14 nonpsychiatric smokers) were studied under smoking satiated, overnight abstinence and smoking reinstatement conditions. Nonsmokers ( n = 30; 15 schizophrenia nonsmokers; 15 nonpsychiatric nonsmokers) were also studied. A comprehensive cognitive battery was administered including verbal learning and memory using the Hopkins Verbal Learning Test-Revised (HVLT-R).

RESULTS

A 2 (diagnosis) × 2 (smoking status) repeated measures analysis of variance with time (session) as the within-subjects factor and diagnosis and smoking status as the between-subject factors was performed for HVLT-R and other cognitive outcomes. Smoking abstinence produced a decline in verbal memory of the HVLT discrimination index in smokers with schizophrenia that was partially revised by reinstatement, although trends for other HVLT measures were not statistically significant.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Acute cigarette smoking and abstinence may selectively alter verbal learning and memory deficits in smokers with schizophrenia compared to nonpsychiatric smoking controls and nonsmokers, but additional studies are needed to confirm the preliminary findings in this small sample. (Am J Addict 2019;00:1-9).

Expression of TCN1 in Blood is Negatively Associated with Verbal Declarative Memory Performance

Memory is indispensable for normal cognitive functioning, and the ability to store and retrieve information is central to mental health and disease. The molecular mechanisms underlying complex memory functions are largely unknown, but multiple genome-wide association studies suggest that gene regulation may play a role in memory dysfunction. We performed a global gene expression analysis using a large and balanced case-control sample (n = 754) consisting of healthy controls and schizophrenia and bipolar disorder patients. Our aim was to discover genes that are differentially expressed in relation to memory performance. Gene expression in blood was measured using Illumina HumanHT-12 v4 Expression BeadChip and memory performance was assessed with the updated California Verbal Learning Test (CVLT-II). We found that elevated expression of the vitamin B12-related gene TCN1 (haptocorrin) was significantly associated with poorer memory performance after correcting for multiple testing (β = −1.50, p = 3.75e-08). This finding was validated by quantitative real-time PCR and followed up with additional analyses adjusting for confounding variables. We also attempted to replicate the finding in an independent case-control sample (n = 578). The relationship between TCN1 expression and memory impairment was comparable to that of important determinants of memory function such as age and sex, suggesting that TCN1 could be a clinically relevant marker of memory performance. Thus, we identify TCN1 as a novel genetic finding associated with poor memory function. This finding may have important implications for the diagnosis and treatment of vitamin B12-related conditions.

Interleukin-3, symptoms and cognitive deficits in first-episode drug-naïve and chronic medicated schizophrenia

Previous studies consistently showed that IL-3 signaling may be involved in the pathophysiology of schizophrenia. However, investigations of associations between IL-3 and the neurocognitive impairments are lacking, including the study of how this may vary with stage of illness. We recruited 45 first-episode drug-naïve (FE-Sz), 35 chronic medicated schizophrenia (Ch-Sz) and 40 healthy controls (HC) and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum IL-3. Altered serum IL-3 levels were found in both patient groups compared with HC group (both p < 0.001). There were significantly lower neurocognitive scores on the RBANS and nearly all of its five subscales, except for Visuospatial/Constructional index in both FE-Sz and Ch-Sz patients vs healthy controls. Moreover, a significant reduction in Immediate memory index (p = 0.021) and a trend-level reduction in RBANS total score (p = 0.094) in Ch-Sz than FE-Sz patients. Interestingly, there was a significant negative correlation between IL-3 and the Immediate memory index only in Ch-Sz patients (p = 0.03). Our findings showed that neurocognitive impairments present in schizophrenia emerge during the first episode with further diminished functioning with disease progression, and IL-3 may be involved in the immediate memory deficits in the chronic phase of schizophrenia.

Intranasal Oxytocin May Improve High-Level Social Cognition in Schizophrenia, But Not Social Cognition or Neurocognition in General: A Multilevel Bayesian Meta-analysis

While there is growing interest in the potential for intranasal oxytocin (IN-OT) to improve social cognition and neurocognition (ie, nonsocial cognition) in schizophrenia, the extant literature has been mixed. Here, we perform a Bayesian meta-analysis of the efficacy of IN-OT to improve areas of social and neurocognition in schizophrenia. A systematic search of original research publications identified randomized controlled trials (RCTs) of IN-OT as a treatment for social and neurocognitive deficits in schizophrenia for inclusion. Standardized mean differences (SMD) and corresponding variances were used in multilevel Bayesian models to obtain meta-analytic effect-size estimates. Across a total of 12 studies (N = 273), IN-OT did not improve social cognition (SMD = 0.07, 95% credible interval [CI] = [-0.06, 0.17]) or neurocognition (SMD = 0.12, 95% CI = [-0.12, 0.34]). There was moderate between study heterogeneity for social cognition outcomes (τs= 0.12). Moderator analyses revealed that IN-OT had a significantly larger effect on high-level social cognition (ie, mentalizing and theory of mind) compared to low-level social cognition (ie, social cue perception) (b = 0.19, 95% CI = [0.05, 0.33]). When restricting our analysis to outcomes for high-level social cognition, there was a significant effect of IN-OT (SMD = 0.20, 95 % CI = [0.05, 0.33]) but the effect was not robust to sensitivity analyses. The present analysis indicates that IN-OT may have selective effects on high-level social cognition, which provides a more focused target for future studies of IN-OT.

Practice and Learning: Spatiotemporal Differences in Thalamo-Cortical-Cerebellar Networks Engagement across Learning Phases in Schizophrenia

BACKGROUND

Understanding how practice mediates the transition of brain-behavior networks between early and later stages of learning is constrained by the common approach to analysis of fMRI data. Prior imaging studies have mostly relied on a single scan, and parametric, task-related analyses. Our experiment incorporates a multisession fMRI lexicon-learning experiment with multivariate, whole-brain analysis to further knowledge of the distributed networks supporting practice-related learning in schizophrenia (SZ).

METHODS

Participants with SZ were compared with healthy control (HC) participants as they learned a novel lexicon during two fMRI scans over a several day period. All participants were trained to equal task proficiency prior to scanning. Behavioral-Partial Least Squares, a multivariate analytic approach, was used to analyze the imaging data. Permutation testing was used to determine statistical significance and bootstrap resampling to determine the reliability of the findings.

RESULTS

With practice, HC participants transitioned to a brain-accuracy network incorporating dorsostriatal regions in late-learning stages. The SZ participants did not transition to this pattern despite comparable behavioral results. Instead, successful learners with SZ were differentiated primarily on the basis of greater engagement of perceptual and perceptual-integration brain regions.

CONCLUSION

There is a different spatiotemporal unfolding of brain-learning relationships in SZ. In SZ, given the same amount of practice, the movement from networks suggestive of effortful learning toward subcortically driven procedural one differs from HC participants. Learning performance in SZ is driven by varying levels of engagement in perceptual regions, which suggests perception itself is impaired and may impact downstream, "higher level" cognition.

The effects of aerobic exercise on cognition in schizophrenia: A 3-month follow-up study

Aerobic exercise (AE) has been shown to improve cognition in patients with schizophrenia. However, it remains unclear whether these exercise-induced cognitive benefits persist beyond the training period. Accordingly, the present study sought to examine the immediate and maintenance effects of AE on a wide range of cognitive functions in 75 schizophrenia patients randomized to 12 weeks of either moderate-intensity treadmill exercise or stretching and toning exercise that served as a control. Participants completed assessments of neurocognition and cardiovascular fitness at pretest, posttest, and 3-month follow-up. The results showed that the AE group outperformed the controls on processing speed and attention at the end of intervention. The two groups did not differ significantly in any cognitive outcome measured at follow-up; however, improvement over time was noted in certain cognitive domains in AE group. The average effect sizes at follow-up were 0.53 and 0.35 for AE and control groups, respectively. There were no significant between-group differences in aerobic fitness at posttest and follow-up, and that fitness level was not related to changes in cognitive performance. These findings provide preliminary evidence for a trend towards beneficial effects of physical activity on cognition over a short follow-up period in favor of AE.

[Subjective cognition in schizophrenia]

OBJECTIVES

Given the extent, magnitude and functional significance of the neurocognitive deficits of schizophrenia, growing attention has been paid recently to patients' self-awareness of their own deficits. Thus far, the literature has shown either that patients fail to recognize their cognitive deficits or that the association between subjective and objective cognition is weak in schizophrenia. The reasons for this lack of consistency remain unexplained but may have to do, among others, with the influence of potential confounding clinical variables and the choice of the scale used to measure self-awareness of cognitive deficits. In the current study, we sought to examine the relationships between subjective and objective cognitive performance in schizophrenia, while controlling for the influence of sociodemographic and psychiatric variables.

METHODS

Eighty-two patients with a schizophrenia-spectrum disorder (DSM-IV criteria) were recruited. Patients' subjective cognitive complaints were evaluated with the Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS), the most frequently used scale to measure self-awareness of cognitive deficits in schizophrenia. Neurocognition was evaluated with working memory, planning and visual learning tasks taken from Cambridge Neuropsychological Tests Automated Battery. The Stroop Color-Word test was also administered. Psychiatric symptoms were evaluated with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. The relationships between subjective and objective cognition were evaluated with multivariate hierarchic linear regression analyses, taking into consideration potential confounders such as sociodemographic and psychiatric variables. Finally, a factor analysis of the SSTICS was performed.

RESULTS

For the SSTICS total score, the regression analysis produced a model including two predictors, namely visual learning and Stoop interference performance, explaining a moderate portion of the variance. Visual learning performance was the most consistent predictor of most SSTICS subscores (e.g. episodic memory, attention, executive functioning, language and praxis). Modest associations were found between the PANSS cognitive factor and objective cognition (e.g. Stroop interference, visual learning, and working memory). Finally, the factor analysis revealed a 6-factor solution that echoes the classification of the items of the SSTICS based on the neuropsychological literature.

CONCLUSIONS

Using a scale having good internal validity, as shown by the factor analysis, the current study highlighted modest associations between subjective and objective cognitive performance, which suggests that schizophrenia patients are only partially aware of their own cognitive deficits. The results also showed a lack of correspondence between the impaired cognitive domain and the domain of cognitive awareness. It should be noted that clinicians were not better than patients at evaluating their cognitive deficits. Future research will need to determine if the observations reported here are schizophrenia-specific or not.

Neurocognition and occupational functioning in schizophrenia spectrum disorders: The MATRICS Consensus Cognitive Battery (MCCB) and workplace assessments

The MCCB is widely used in clinical trials of schizophrenia, but its relationship to occupational functioning still needs further elaboration. While previous research has indicated that various domains of neurocognition assessed by individual tests are related to work functioning, these reports preceded the development of the MCCB as the standard neurocognitive test battery in the field. In the current study, the vocational functioning of 131 Norwegian participants with schizophrenia spectrum disorders who were enrolled in a vocational rehabilitation program were assessed on the Vocational Cognitive Rating Scale (VCRS), the Work Behavior Inventory (WBI), and the Complexity Scale (CS) as well as on the MCCB. Significant correlations were found between most MCCB domains and VCRS Total Score. MCCB processing speed and attention were most powerfully related to and predictive of WBI scores. When participants were divided into "low complexity" or "higher complexity" work categories, participants in the "low-complexity" group performed significantly worse than participants in the "higher-complexity" group regarding processing speed, working memory, visual learning and the composite score. The same pattern emerged for participants working sheltered compared to competitive jobs. The VCRS, WBI and CS may be useful in vocational rehabilitation. They bridge an important gap between test- and occupational-setting, providing valuable information about impairments related to occupational functioning. We found the MCCB to be sensitive to occupational functioning as measured by VCRS, WBI and CS, with neurocognition accounting for a small but significant proportion of the variance in these different measures of occupational functioning.

High estradiol levels improve false memory rates and meta-memory in highly schizotypal women

Overconfidence in false memories is often found in patients with schizophrenia and healthy participants with high levels of schizotypy, indicating an impairment of meta-cognition within the memory domain. In general, cognitive control is suggested to be modulated by natural fluctuations in oestrogen. However, whether oestrogen exerts beneficial effects on meta-memory has not yet been investigated. The present study sought to provide evidence that high levels of schizotypy are associated with increased false memory rates and overconfidence in false memories, and that these processes may be modulated by natural differences in estradiol levels. Using the Deese-Roediger-McDermott paradigm, it was found that highly schizotypal participants with high estradiol produced significantly fewer false memories than those with low estradiol. No such difference was found within the low schizotypy participants. Highly schizotypal participants with high estradiol were also less confident in their false memories than those with low estradiol; low schizotypy participants with high estradiol were more confident. However, these differences only approached significance. These findings suggest that the beneficial effect of estradiol on memory and meta-memory observed in healthy participants is specific to highly schizotypal individuals and might be related to individual differences in baseline dopaminergic activity.

Poor premorbid school performance, but not severity of illness, predicts cognitive decline in schizophrenia in midlife

Neurocognitive dysfunction is common in schizophrenia but its course and determinants remain uncertain. Our aim was to analyse if premorbid school performance and the severity of illness and functioning predict change in cognition in schizophrenia in a general population sample. The sample included cases with schizophrenia spectrum disorder from the Northern Finland Birth Cohort 1966. Data on school marks at the age of 16 years, educational level at the age of 34 years, severity of symptoms and occupational functioning around first episode and after years of illness were gained from national registers, hospital notes and interviews. Change of verbal and visual learning and memory and executive functioning were examined between ages 34 and 43 years. The number of cases varied in analyses from 29 to 41, depending on missing data in particular cognitive tests. Lower school marks at age 16 years and lower education at age 34 years predicted more decline of cognition. Measures of severity of illness or functioning were not associated statistically significantly with change of cognition. Premorbid school performance, but not later course of schizophrenia, related to change of cognition in midlife. Poor premorbid scholastic performance and post-onset cognitive decline may represent related processes as part of an endophenotype of schizophrenia.

Neuropsychological Impairment in Prodromal, First-Episode, and Chronic Psychosis: Assessing RBANS Performance

BACKGROUND

Cognitive deficits are observed throughout all developmental phases of psychosis. However, prior studies have usually focused on a limited illness period and used a wide variety of cognitive instruments. Therefore, it has been difficult to characterize or highlight cognitive functioning in different stages of psychosis.

METHOD

We administered the RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) tests to 4 participant subgroups, including healthy volunteers (controls, HC, n = 28), subjects at high risk for clinical psychosis (prodrome, CHR, n = 27), first-episode schizophrenia patients (FE-Sz, n = 26), and mid-term and long-term chronic schizophrenia patients (Ch-Sz, n =147). Comparison, correlation, and regression analyses of RBANS index scores were assessed among groups. We examined clinical outcomes over 2 years between the CHR and HC subjects, and RBANS domains were used as possible predictors for conversion to psychosis.

RESULTS

Performance on all RBANS domains was significantly impaired during a post-onset stage of psychosis (FE-Sz and Ch-Sz), and RBANS scores declined along with disease progression. Regression analyses showed that for CHR and HC subjects, baseline impairment in delayed memory (DM) significantly predicted conversion to psychosis. Additionally, partial correlations showed that for FE-Sz and Ch-Sz subjects, DM was the only correlate with a later stage of psychosis.

CONCLUSIONS

Cognitive deficits broadly emerged, and diminished functioning followed along with disease progression. Impairment in DM is perhaps one domain that helps us understand the development of psychosis. A critical need is to monitor and treat memory functioning for psychotic patients throughout all phases of the disease.

Antipsychotic-induced parkinsonism is associated with working memory deficits in schizophrenia-spectrum disorders

In view of the significant cognitive deficits in schizophrenia and their impact on patients' social and occupational functioning, and considering that the influence potential influence of antipsychotic-induced extrapyramidal symptoms on cognition in schizophrenia remains poorly understood, the current study sought to identify the clinical, socio-demographic and neurologic predictors of the cognitive performance of schizophrenia patients. Eighty-two schizophrenia-spectrum (DSM-IV criteria) outpatients were recruited. Psychiatric symptoms were evaluated with the Positive And Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. Extrapyramidal symptoms were evaluated with the Extrapyramidal Symptoms Rating Scale, while spatial working, planning abilities and visual paired associates learning were evaluated with the CAmbridge Neuropsychological Tests Automated Battery. The Stroop test was also administered. Multivariate hierarchic linear regression analyses were performed. We found that negative symptoms were associated with cognitive flexibility, planning, visual learning and working memory performance in schizophrenia. Age, sex, number of hospitalizations and antipsychotic type also emerged as significant predictors. More importantly, we found a significant association between antipsychotic-induced parkinsonism and working memory performance. The fact that negative symptoms and socio-demographic variables predicted cognitive performance in schizophrenia is consistent with the previous literature on the topic. The finding of an association between parkinsonism and working memory may have clinical implications, since working memory deficits are considered putative endophenotypes of schizophrenia and are known to impair patients' social and occupational functioning. Our results will need to be replicated in longitudinal studies involving larger samples of patients.

Neuropsychology, autobiographical memory, and hippocampal volume in "younger" and "older" patients with chronic schizophrenia

Despite a wide range of studies on neuropsychology in schizophrenia, autobiographical memory (AM) has been scarcely investigated in these patients. Hence, less is known about AM in older patients and hippocampal contribution to autobiographical memories of varying remoteness. Therefore, we investigated hippocampal volume and AM along with important neuropsychological domains in patients with chronic schizophrenia and the respective relationships between these parameters. We compared 25 older patients with chronic schizophrenia to 23 younger patients and an older healthy control group (N = 21) with respect to AM, additional neuropsychological parameters, and hippocampal volume. Personal episodic and semantic memory was investigated using a semi-structured interview. Additional neuropsychological parameters were assessed by using a battery of standard neuropsychological tests. Structural magnetic resonance imaging data were analyzed with an automated region-of-interest procedure. While hippocampal volume reduction and neuropsychological impairment were more pronounced in the older than in the younger patients, both groups showed equivalent reduced AM performance for recent personal episodes. In the patient group, significant correlations between left hippocampal volume and recent autobiographical episodes as well as personal semantic memories arose. Verbal memory and working memory were significantly correlated with right hippocampal volume; executive functions, however, were associated with bilateral hippocampal volumes. These findings underline the complexity of AM and its impairments in the course of schizophrenia in comparison to rather progressive neuropsychological deficits and address the importance of hippocampal contribution.

Lifetime use of antipsychotic medication and its relation to change of verbal learning and memory in midlife schizophrenia - An observational 9-year follow-up study

BACKGROUND

The association between the course of cognition and long-term antipsychotic medication in schizophrenia remains unclear. We analysed the association between cumulative lifetime antipsychotic medication dose and change of verbal learning and memory during a 9-year follow-up.

METHOD

Forty schizophrenia subjects and 73 controls from the Northern Finland Birth Cohort 1966 were assessed by California Verbal Learning Test (CVLT) at the ages of 34 and 43 years. Data on the lifetime antipsychotic doses in chlorpromazine equivalents were collected. The association between antipsychotic dose-years and baseline performance and change in CVLT was analysed, controlling for baseline performance, gender, age of onset and severity of illness.

RESULTS

Higher antipsychotic dose-years by baseline were significantly associated with poorer baseline performance in several dimensions of verbal learning and memory, and with a larger decrease in short-delay free recall during the follow-up (p=0.031). Higher antipsychotic dose-years during the follow-up were associated with a larger decrease of immediate free recall of trials 1-5 during the follow-up (p=0.039). Compared to controls, decline was greater in some CVLT variables among those using high-doses, but not among those using low-doses.

CONCLUSION

This is the first report of an association between cumulative lifetime antipsychotic use and change in cognition in a long-term naturalistic follow-up. The use of high doses of antipsychotics may be associated with a decrease in verbal learning and memory in schizophrenia years after illness onset. The results do not support the view that antipsychotics in general prevent cognitive decline or promote cognitive recovery in schizophrenia.

The emerging roles of TCF4 in disease and development

Genome-wide association studies have identified common variants in transcription factor 4 (TCF4) as susceptibility loci for schizophrenia, Fuchs' endothelial corneal dystrophy, and primary sclerosing cholangitis. By contrast, rare TCF4 mutations cause Pitt-Hopkins syndrome, a disorder characterized by intellectual disability and developmental delay, and have also been described in patients with other neurodevelopmental disorders. TCF4 therefore sits at the nexus between common and rare disorders. TCF4 interacts with other basic helix-loop-helix proteins, forming transcriptional networks that regulate the differentiation of several distinct cell types. Here, we review the role of TCF4 in these seemingly diverse disorders and discuss recent data implicating TCF4 as an important regulator of neurodevelopment and epithelial-mesenchymal transition.

Quality of life in stable schizophrenia: the relative contributions of disorganization and cognitive dysfunction

OBJECTIVE

The purpose of this study was to examine the relative contributions of disorganization and cognitive dysfunction to quality of life (QOL) in patients with stable schizophrenia.

METHODS

A total of 276 consecutive outpatients with stable schizophrenia were enrolled in a cross-sectional study. We performed a mediation analysis to assess the specific effect of disorganization on QOL, as assessed by the Heinrichs-Carpenter Quality of Life Scale (QLS), and the possible mediating role of cognitive dysfunction.

RESULTS

Our findings were as follows: (i) disorganization was negatively related to the total QLS score; (ii) disorganization was negatively related to two of the four QLS domains, namely the role-functioning domain (occupational/educational) and the intrapsychic functioning domain (e.g., motivation, curiosity, and empathy); and (iii) verbal memory was a partial mediator of the relationship between disorganization and QLS (the total score and the two above-mentioned domains).

CONCLUSIONS

Disorganization demonstrated direct and indirect effects via verbal memory on two domains of functioning, as measured by the QLS. These results highlight the importance of improving disorganization and cognition (particularly verbal memory) to improve the functional outcomes of patients with schizophrenia.

Neurocognition: clinical and functional outcomes in schizophrenia

Schizophrenia is characterized by significant heterogeneity in outcome. The last decades have witnessed a significant interest in identifying factors that can moderate or influence clinical and functional outcomes in people with schizophrenia. One factor of particular interest is neurocognition, as performance on various measures of cognitive abilities, such as memory, attention, and executive functions, have been consistently related to functional outcome and, to a lesser extent, clinical outcome. This review aims to provide an up-to-date description of recent studies examining the association between neurocognition and clinical and (or) functional outcomes. In the first section, studies examining neurocognitive performance in relation to clinical outcome are examined. When clinical outcome is defined dichotomously (for example, comparing remitted and nonremitted), verbal memory performance consistently exhibits a strong association with clinical status, with the poor outcome group showing the largest deficits. In the second section, studies exploring the relation between neurocognition and various dimensions of functional outcome are reviewed. These dimensions include independent living, social functioning, and vocational functioning, among others. Again, a strong link between neurocognitive deficits and impairments in several aspects of functioning clearly emerges from this review. Finally, several measurement issues are discussed that pertain to the need to standardize definitions of clinical and (or) functional outcomes, the importance of defining cognitive domains consistently across studies, and distinguishing between one's competence to perform tasks and what one actually does in everyday life. Addressing these measurement issues will be key to studies examining the development of effective interventions targeting neurocognitive functions and their impact on clinical and functional outcomes.

The neurobiological bases of memory formation: from physiological conditions to psychopathology

The formation of long-term memories is a function necessary for an adaptive survival. In the last two decades, great progress has been made in the understanding of the biological bases of memory formation. The identification of mechanisms necessary for memory consolidation and reconsolidation, the processes by which the posttraining and postretrieval fragile memory traces become stronger and insensitive to disruption, has indicated new approaches for investigating and treating psychopathologies. In this review, we will discuss some key biological mechanisms found to be critical for memory consolidation and strengthening, the role/s and mechanisms of memory reconsolidation, and how the interference with consolidation and/or reconsolidation can modulate the retention and/or storage of memories that are linked to psychopathologies.

Differential cognitive performances between schizophrenic responders and non-responders to antipsychotics: correlation with course of the illness, psychopathology, attitude to the treatment and antipsychotics doses

Multiple lines of evidence demonstrate that schizophrenia patients may perform worse than normal controls in several cognitive tasks. However, little is known on putative differences in cognitive functioning between schizophrenia patients responding to antipsychotics and those resistant to the treatment. In this cross-sectional study, 63 subjects (41 schizophrenia and schizoaffective patients and 22 age and sex-matched controls) were enrolled. Patients were divided in resistant (TRS, n=19) and non-resistant to pharmacological treatment (non-TRS, n=22) according to the American Psychiatric Association (APA) criteria for treatment resistance. The Brief Assessment of Cognition in Schizophrenia (BACS) was administered to patients and controls. The following rating scales were administered to schizophrenia patients: the Positive and Negative Syndrome Scale (PANSS), the Drug Attitude Inventory (DAI) and the Subjective Well-being under Neuroleptics (SWN). Statistically significant differences among non-TRS patients, TRS ones, and controls were detected at the BACS. TRS patients performed significantly worse than non-TRS ones on Verbal Memory task, exhibited higher PANSS total and subscales scores and were prescribed higher antipsychotic doses. Poorer performances at the BACS significantly correlated with more severe negative symptoms in TRS but not in non-TRS patients. These results may suggest that TRS patients suffer from a form of the disease with prominent cognitive impairment possibly related to negative symptoms.

Is Central Auditory Processing Disorder Present in Psychosis?

Purpose

The scope of this study was to trace central auditory processing issues in patients with first-episode psychosis using a psychoacoustic test battery approach.

Method

Patients ( n = 17) and volunteer control subjects ( n = 17) with no personal or family history of schizophrenia were included in the study on the basis of normal hearing sensitivity. The authors implemented a central auditory processing battery consisting of monaural and binaural tests with verbal and nonverbal stimuli.

Results

Perceptual deficits in both nonverbal and verbal auditory stimuli are reported in this study, with temporal central auditory processing deficits and a mean left-ear advantage documented in the patient group.

Conclusion

This study points to the possibility of the existence of central auditory processing deficits in first-episode psychosis leading to schizophrenia. Audiologists should be aware of the psychiatric research pointing to enhanced verbal memory as a result of auditory training, linking bottom-up remediation with top-down improvement.

Verbal memory impairment in healthy siblings of patients with schizophrenia

Cognitive deficits have been recognized as a core feature of schizophrenia (SZ) and are present in most patients. Verbal memory (VM), working memory (WM), and executive function (EF) are domains commonly impaired in patients with SZ. These latter domains have been related to the genetic risk of the disorder characterizing as possible endophenotypes. In order to study neurocognitive endophenotypes in a Brazilian population with elevated genetic risks to develop SZ, we measured VM (Hopkins Verbal Learning Test Revised), WM (Letter-Number Sequencing and Digit Span) and EF (Stroop Test) in 90 subjects (45 unaffected siblings of patients with SZ and 45 matched healthy controls). No differences were found in EF and WM (Letter-Number Sequencing and Digit Span). However, in VM, siblings of patients performed worse than controls on the immediate recall and delayed recall. Our results suggest that VM impairment could be considered an endophenotype of SZ.

Ten year neurocognitive trajectories in first-episode psychosis

Objective: Neurocognitive impairment is commonly reported at onset of psychotic disorders. However, the long-term neurocognitive course remains largely uninvestigated in first episode psychosis (FEP) and the relationship to clinically significant subgroups even more so. We report 10 year longitudinal neurocognitive development in a sample of FEP patients, and explore whether the trajectories of cognitive course are related to presence of relapse to psychosis, especially within the first year, with a focus on the course of verbal memory.

Method: Forty-three FEP subjects (51% male, 28 ± 9 years) were followed-up neurocognitively over five assessments spanning 10 years. The test battery was divided into four neurocognitive indices; Executive Function, Verbal Learning, Motor Speed, and Verbal Fluency. The sample was grouped into those relapsing or not within the first, second and fifth year.

Results: The four neurocognitive indices showed overall stability over the 10 year period. Significant relapse by index interactions were found for all indices except Executive Function. Follow-up analyses identified a larger significant decrease over time for the encoding measure within Verbal Memory for patients with psychotic relapse in the first year [F_{(4, 38)} = 5.8, p = 0.001, η² = 0.40].

Conclusions: Main findings are long-term stability in neurocognitive functioning in FEP patients, with the exception of verbal memory in patients with psychotic relapse or non-remission early in the course of illness. We conclude that worsening of specific parts of cognitive function may be expected for patients with on-going psychosis, but that the majority of patients do not show significant change in cognitive performance during the first 10 years after being diagnosed.

Verbal learning and memory and psychopathology in schizophrenia

BACKGROUND AND AIMS

Verbal learning and memory (VLM) are the most impaired cognitive functions noted in schizophrenia. Though its association with negative symptoms is found consistently, only few have compared this relationship at a drug free/naïve state and on antipsychotic medications. Thus the aim of the study was to compare VLM functions in schizophrenia and normal controls and find its association between negative symptoms at drug free/naïve state and on antipsychotic medication.

METHOD

A sample of 78 initially drug naïve/free patients of schizophrenia of either sex, aged between 18 and 45 years, and 30 age, sex and education matched normal controls were assessed for VLM by Rey-Auditory-Verbal-Learning-Test (RAVLT). The schizophrenia group was assessed at baseline and at the end of six weeks treatment with RAVLT and for positive, negative and depressive symptoms.

RESULTS

The schizophrenia group performed significantly poorly on VLM at both time points compared to normal controls, though significant improvement in the schizophrenia group was noted following six weeks treatment. Only negative symptoms inversely correlated with immediate memory span and verbal learning at baseline and in addition verbal memory at six weeks, while change in any of the dimensions of psychopathology (assessed in terms of positive, negative and depressive symptoms) over six weeks did not correlate with change in measures of cognitive functions.

CONCLUSION

For VLM deficits in schizophrenia, though correlated with negative symptoms, improvement with treatment could not be attributed to improvement in psychopathology.

Predictors of neurocognitive impairment at 3 years after a first episode non-affective psychosis

BACKGROUND

Neurocognitive impairment is a core component of schizophrenia. However, patients show great variability in the level and course of deficits. The goal of the present longitudinal study was to identify predictors of neurocognitive impairment in first episode psychosis patients.

METHODS

Neurocognitive performance was analyzed in a cohort of 146 patients 3 years after a first episode non-affective psychosis. Subgroups, impaired vs. unimpaired, were compared on baseline clinical, neuropsychological, premorbid and sociodemographic characteristics.

RESULTS

Fifty-nine percent of participants presented general neurocognitive impairment and regression analyses demonstrated that clinical and sociodemographic characteristics were not predictive variables. A model composed of premorbid IQ, verbal memory and motor dexterity correctly classified 79.6% of the individuals.

CONCLUSIONS

The present study gives information on frequency and neurocognitive profile of subtypes of patients showing impairment. Our results suggest general neurocognitive impairment is a trait dimension of the disorder related to specific cognitive dysfunctions.

Duration of untreated negative and positive symptoms of psychosis and cognitive impairment in first episode psychosis

BACKGROUND

Duration of untreated psychosis (DUP) has been significantly associated with poor clinical and social outcomes in First Episode Psychosis (FEP) patients, but an association with cognitive outcomes has not been clearly established.

METHOD

Seventy-seven consecutively admitted, drug-naïve patients with FEP were assessed at baseline and at 1month and 6months. Underlying dimensions of DUP (general prodrome and positive, negative and disorganisation symptoms) were assessed using the Symptom Onset in Schizophrenia (SOS) inventory (Perkins et al., 2000). To assess the effect of DUP on the neuropsychological status of the patients, a linear mixed-effect model was fitted to each neuropsychological dimension. These models included a dichotomised version of DUP (short versus long duration) as a fixed effect, several adjusting variables to account for patient differences, and a random effect to incorporate the longitudinal structure of the data.

RESULTS

Patients with a short duration of untreated negative symptoms (DUNS) or a short duration of untreated positive symptoms (DUPS) outperformed patients with a long duration of untreated symptoms on memory tasks and a pre-attentional visual task but not on measures of verbal fluency, attention, reaction time, visual processing and executive functions.

CONCLUSIONS

This study provides additional support for an early intervention to shorten DUP to facilitate a better outcome in memory and attentional domains of FEP patients.

Cognitive function and competitive employment in schizophrenia: relative contribution of insight and psychopathology

PURPOSE

This study investigated the relationships among insight, psychopathology, cognitive function, and competitive employment in order to determine whether insight and/or psychopathology carried the influence of cognitive function to competitive employment.

METHODS

We recruited 253 outpatients with stable schizophrenia and we further divided our sample into two groups of patients (unemployed and competitive employment subjects). Clinical and neuropsychological assessments were performed. All clinical variables significantly different between the two groups of subjects were subsequently analyzed using a binary logistic regression to assess their independent contribution to competitive employment in the two patients' groups. On the basis of the regression results two mediation analyses were performed.

RESULTS

Verbal memory, general psychopathology, and awareness of mental illness were significantly associated with competitive employment in our sample. Both awareness of mental illness and general psychopathology had a role in mediating the verbal memory-competitive employment relationship.

CONCLUSIONS

Taken together, these findings confirmed the importance of cognitive function in obtaining competitive employment. Our results also highlighted the independent role of general psychopathology and awareness of illness on occupational functioning in schizophrenia. Thus, a greater attention must be given to the systematic investigation of insight and general psychopathology in light of an amelioration of vocational functioning in stable schizophrenia.

Functional magnetic resonance imaging correlates of memory encoding in relation to achieving remission in first-episode schizophrenia

BACKGROUND

Previous studies in schizophrenia have shown a strong relationship between memory deficits and a poor clinical outcome. However, no previous study has identified the functional neural correlates of memory encoding in relation to remission.

AIMS

To determine whether functional magnetic resonance imaging (fMRI) activation patterns differed between individuals that later achieved remission v. those who did not.

METHOD

Forty-two participants with first-episode schizophrenia were divided into two groups after 1 year of treatment as per the 2005 remission in schizophrenia consensus definition. We then examined fMRI activation using three contrasts (associative v. item-oriented strategy, semantically unrelated v. related image pairs, and successful v. unsuccessful memory encoding) among 15 participants who had achieved remission (remitted group), 27 who had not (non-remitted group) and 31 healthy controls (control group).

RESULTS

Participants in the non-remitted group displayed a positive activation in the posterior cingulate compared with those in the remitted group when encoding related images; no significant differences between the two groups were identified for the other contrasts. From the behavioural data, compared with the remitted and control groups, the non-remitted group demonstrated an inability to encode related images and displayed worse recognition memory overall.

CONCLUSIONS

This is the first study to identify differential neural activation between individuals with first-episode schizophrenia that later achieved remission v. those who did not. The behavioural and functional results together add to the growing evidence relating a poor clinical outcome in schizophrenia to memory-related deficits.

Memory blocking in schizophrenia reflects deficient retrieval control mechanisms

Retrieval interference and orthographic processing were evaluated in schizophrenia, schizotypal personality disorder, and non-psychiatric control participants using a word fragment completion paradigm. Participants studied solutions and later completed corresponding fragments preceded by solutions, orthographically similar blocking words, or ampersands. Although schizophrenia patients completed fewest fragments, they showed equivalent repetition priming and blocking magnitude, supporting intact orthographic processing. Schizophrenia patients were more likely to commit intrusions in the blocking condition, whereas control participants displayed better mental control because they were more likely to withhold the response. These results suggest schizophrenia patients show abnormal functioning of control mechanisms responsible for selection and inhibition of competitors.

Why do patients with schizophrenia who have poor insight still take antipsychotics? Memory deficits as moderators between adherence belief and behavior

While lack of insight is often predictive of antipsychotic nonadherence, some inconsistency in the literature remains unexplained. Verbal memory deficits may moderate the association between insight and adherence. Based on cross-sectional data, outpatients treated with antipsychotics for a psychotic disorder were divided into those with good (n=53) and poor (n=59) memory. Poor insight predicted nonadherence only among the subgroup with relatively good memory (r=0.43; P<0.01), but had no effect in the subgroup with worse memory (r=0.08; ns). Structural equation modelling revealed significant moderation (χ=4.72; df=1; P<0.05), which means that a significantly better model fit was found by allowing the analysis to differentiate between the two memory groups. Thus, poor insight was only associated with poor medication adherence among patients with relatively good memory. We speculate that memory deficits commonly associated with schizophrenia may partly explain why poor insight does not always lead to poor medication adherence.

The parahippocampal gyrus as a neural marker of early remission in first-episode psychosis: a voxel-based morphometry study

INTRODUCTION

Outcome from psychotic disorders is heterogeneous with poor long-term clinical outcome associated with such markers as decreased internal capsule volume and increased ventricular volumes. No previous study has examined neuroimaging markers in relation to early remission.

METHODS

This neuroimaging study included 68 previously untreated first episode of psychosis (FEP) patients, of whom 28 achieved remission and 40 did not after six months of treatment, and 42 healthy controls. Using voxel-based morphometry (VBM), we set out to determine if specific neural correlates could be identified in FEP patients not achieving remission in a specialized early-intervention service.

RESULTS

Nonremitted patients had significant lower grey matter concentration (GMC) in the parahippocampal gyrus bilaterally compared to remitted patients. A classification model utilizing parahippocampal GMC correctly classified remission status 79% of the time and accounted for 56% of the variance. Moreover, GMC on the left (r=-0.35, p=0.004) and right (r=-0.47, p<0.0001) side correlated with social withdrawal while only the left side correlated with verbal memory (r=0.21, p=0.03).

CONCLUSIONS

Neural markers of early remission are present in first-episode patients. A better understanding of the neural etiology of psychosis and its relationship to outcome may encourage the search for new medications to help improve outcome in relation to the identified brain regions like the parahippocampal gyrus.

Polymorphism of serotonin receptor genes (5-HTR2A) and Dysbindin (DTNBP1) and individual components of short-term verbal memory processes in Schizophrenia

Associations between polymorphisms in the T102C and A-1438G loci of the 5-HTR2A and the P1763 and P1578 markers of the DTNBP1 gene with the overall productivity and individual subprocesses of shortterm verbal memory were studied in 4-5 patients with schizophrenia and 290 healthy subjects. Subjects were asked to reproduce immediately two lists of 10 words. The overall productivity of reproduction was assessed, along with the reproduction productivity of the first list (immediate memory or general attention), the effect of proactive interference, and the number of intrusions. Patients were significantly different from controls on all measures. Patients showed decreases in overall task performance productivity, in immediate memory productivity, and in the effect of proactive interference; fewer intrusions were seen. Both markers of the 5-HTR2A gene were associated with short-term memory productivity in the combined cohort: assessments were worse in T102C CC and A-1438G GG homozygotes. The P1763 marker of the DTNBP1 gene, conversely, had significant influences on the memory subprocesses reflected in the levels of interference and intrusions but had insignificant influence on overall productivity. Homozygotes for P1763G GG had the worst parameters. Overall, these data are consistent with the concept that these polymorphic genes are involved in different subprocesses of short-term memory both in normal subjects and in patients with schizophrenia.

Cognitive functioning in subjects with recent-onset psychosis from a low-middle-income environment: multiple-domain deficits and longitudinal evaluation

Cognitive deficits are a key feature of recent-onset psychosis, but there is no consensus on whether such deficits are generalized or confined to specific domains. Besides, it is unclear whether cognitive deficits: a) are found in psychotic patients in samples from outside high-income countries; and b) whether they progress uniformly over time in schizophrenia and affective psychoses. We applied 12 tests organized into eight cognitive domains, comparing psychosis patients (n = 56, time from initial contact = 677.95+/-183.27 days) versus healthy controls (n=70) recruited from the same area of São Paulo, Brazil. Longitudinal comparisons (digit span and verbal fluency) were conducted between a previous assessment of the subjects carried out at their psychosis onset, and the current follow-up evaluation. Psychosis patients differed significantly from controls on five domains, most prominently on verbal memory. Cognitive deficits remained detectable in separate comparisons of the schizophrenia subgroup and, to a lesser extent, the affective psychosis subjects against controls. Longitudinal comparisons indicated significant improvement in schizophrenia, affective psychoses, and control subjects, with no significant group-by-time interactions. Our results reinforce the view that there are generalized cognitive deficits in association with recent-onset psychoses, particularly of non-affective nature, which persist over time.

Neural markers of remission in first-episode schizophrenia: a volumetric neuroimaging study of the hippocampus and amygdala

OBJECTIVE

The temporolimbic region has been implicated in the pathophysiology in schizophrenia. More specifically, significantly smaller hippocampal volumes but not amygdala volumes have been identified at onset in first-episode schizophrenia (FES) patients. However, volumetric differences (namely, in the hippocampus) exhibit an ambiguous relationship with long-term outcome. So, we examined the relationship between hippocampus and amygdala volumes and early remission status.

METHODS

We compared hippocampus and amygdala volumes between 40 non-remitted and 17 remitted FES patients and 57 healthy controls. Amygdala and hippocampus were manually traced with the hippocampus additionally segmented into three parts: body, head, and tail. Remission was defined as mild or less on both positive and negative symptoms over a period of 6 consecutive months as per the 2005 Remission in Schizophrenia Working Group criteria.

RESULTS

A significant [group x structure x side] interaction revealed outcome groups differed in hippocampus tail volumes; significantly on the left (non-remitted=694+/-175 mm(3); remitted=855+/-133 mm(3); p=0.001) with a trend difference on the right (non-remitted=723+/-162 mm(3); remitted=833+/-126 mm(3); p=0.023). Groups did not differ in body, head, or amygdala volumes bi-laterally.

CONCLUSIONS

A smaller hippocampal tail volume may represent a neural marker in FES patients who do not achieve early remission after the first 6 months of treatment. The early identification of patients with poor outcome with respect to the hippocampus tail may encourage the search for new, more target-specific, medications in hope of improving outcome and moving us towards a better understanding of the pathophysiology of schizophrenia.

True and false autobiographical memories in schizophrenia: preliminary results of a diary study

The frequency of true and false autobiographical memories and associated states of conscious awareness, i.e., conscious recollection and simply knowing, as well as the respective roles of affective and cognitive processes in autobiographical memory construction, were assessed in eight patients with schizophrenia and eight control participants. A diary study methodology was used in combination with the Remember/Know procedure. The results showed a higher frequency of Know responses associated with the retrieval of both true and false memories in patients than in control participants. Whereas control participants rated higher at retrieval than at encoding the distinctiveness and personal importance of events, as well as the extent to which events furthered current personal plans, patients exhibited an opposite pattern of ratings, with ratings being lower at retrieval than at encoding. These preliminary results show a high frequency of simply knowing associated with the retrieval of true and false autobiographical memories in patients with schizophrenia and provide evidence for the interest of the diary study methodology for studying autobiographical memory in schizophrenia.

Social skills and neurocognitive individualized training in schizophrenia: comparison with structured leisure activities

Cognitive impairment and deficits in social skills have been largely documented in patients with schizophrenia and are increasingly recognized as rate-limiting factors for recovery. Evidence has been provided that cognitive training and social skills training (SST) are effective to treat cognitive and social skills impairment in schizophrenia; however, the translation of improved performance on cognitive or social skills tasks into improved functional outcome is controversial. According to recent reviews, interventions providing cognitive training in conjunction with psychosocial rehabilitation have a greater impact on functional outcome than either intervention alone suggesting that the two treatment approaches may work together in a synergistic fashion. The present pilot study was designed to test the hypothesis that an integrated rehabilitation program, including individualized cognitive and SST, is more effective than the structured leisure activities (SLA) carried out in many Italian Mental Health Departments. The primary outcome measure was subjects' personal and social functioning as assessed by the Interview for the assessment of disability. The study is based on a controlled design including randomization to treatment groups, blind assessments and stable pharmacological treatment. Subjects were recruited among patients attending three psychiatric facilities located in the Italian region Campania. Thirty patients were randomized to the experimental program "social skills and neurocognitive individualized training" (SSANIT), and 30 to SLA. The two programs were matched for the overall duration as well as frequency and duration of the sessions. The two groups of patients did not differ at baseline on psychopathology, neurocognitive and personal/social functioning. After 6 months of treatment, personal and social functioning was significantly better in patients assigned to SSANIT than in those assigned to usual rehabilitation activities practiced in Mental Health Departments. No advantage was observed for either program on psychopathological and cognitive outcome indices. As for other integrated programs, also for SSANIT further studies are needed to verify generalization and persistence of the observed gains, and to clarify most adequate length and doses of the therapeutic intervention as well as the relative contribution of each program component to its impact on subjects' disability.

Functional mechanisms of episodic memory impairment in schizophrenia

OBJECTIVE

To achieve a better understanding of the functional mechanisms underlying episodic memory dysfunction in schizophrenia, which is a prerequisite for unravelling schizophrenia's neural correlates in neuroimaging studies and, more generally, for developing an integrated approach to the pathophysiology of schizophrenia. It is also crucial for developing cognitive remediation.

METHOD

This paper reviews empirical evidence of episodic memory dysfunction in schizophrenia obtained with reference to various theoretical models of episodic memory.

RESULTS

All the studies converge to show a significant impairment of the critical feature of episodic memory: conscious recollection. Schizophrenia is also associated with a defect of autobiographical memory. The episodic memory dysfunction results from a predominant failure of strategic processing at encoding, although an impairment of strategic processing at retrieval cannot be ruled out. The possibility that it is not the execution of the encoding strategies that is defective but, rather, their self-initiation by the patients is plausible.

CONCLUSIONS

These findings may explain some behavioural abnormalities associated with schizophrenia, notably, inadequate functional outcomes in everyday life. They may also have implications for cognitive remediation and better social and work functioning of patients with schizophrenia.

Interaction of dopamine system genes and cognitive functions in patients with schizophrenia and their relatives and in healthy subjects from the general population

Linkage between the DRD4 and COMT genes and cognitive measures characterizing verbal memory, executive functions, and associative processes was studied in 150 patients with schizophrenia, 83 of their relatives, and 118 mentally healthy subjects without any family history of psychoses, with the aim of detecting the main effects of the polymorphic markers -809G/A and -521C/T (DRD4) and Val158Met (COMT) when present individually and together. The group of patients showed a main effect for polymorphism -521C/T on verbal fluency and an effect of the interaction of this polymorphism and the COMT gene on this cognitive trait. The highest level of verbal fluency was seen among carriers of the Val/Val+CC and Met/Met+TT genotypes. In the combined group of unaffected individuals, the interaction of the COMT and DRD4 -521C/TT genotypes had an effect on the standardness of speech associations due to a decrease in the standardness of associations in carriers of the Met/Met+CC genotype. Finally, both patients and unaffected individuals showed an effect for the interaction between the COMT and DRD4 -809G/A genotypes on working memory. Patients and healthy subjects showed similar features: the highest values were seen in subjects homozygous for the Val and G alleles, while the lowest values were seen in homozygotes for the Met and A alleles. These data provide evidence for a relationship between the DRD4 and COMT genes and different aspects of executive functions and the absence of such a relationship in relation to verbal memory.

The association between cognitive functioning and occupational status in persons with a recent onset of psychosis

The ability to engage in occupational activity is an important aspect of functioning in individuals with recent onset psychosis. We measured the determinants of occupational status in a sample of n = 86 adults with a recent onset of affective or nonaffective psychosis. Participants were evaluated with the Repeatable Battery of Neuropsychological Status, the Wisconsin Card Sorting Test, symptom rating scales, and other clinical and demographic measures. Results of a discriminant function analysis indicated that the most significant differences between those who worked or attended school and those who did not could be attributed to better immediate verbal memory (F = 13.16, p < .0005) and the absence of substance abuse (F = 5.17, p = .026). Occupational activity was not significantly associated with age, gender, race, or symptom severity in this population. Cognitive assessments may prove useful to identify recent onset patients who are most at risk for occupational impairment and who could most benefit from therapeutic interventions.

Rivastigmine treatment as an add-on to antipsychotics in patients with schizophrenia and cognitive deficits

OBJECTIVE

Although new atypical antipsychotic agents have been found to improve overall cognitive function in patients with schizophrenia (SZ), some aspects of memory, attention and executive functions still remain impaired. Acetylcholinesterase (AChE) inhibitors, such as rivastigmine, have been shown to improve cognition in other disorders, particularly Alzheimer's disease. Dysfunctions in cholinergic systems, especially in the prefrontal cortex, have been identified in SZ, suggesting that cholinesterase inhibitors may be effective in treating cognitive deficits in this disease.

RESEARCH DESIGN AND METHODS

Using a randomized crossover design, we assessed SZ patients with stable symptoms and poor cognitive functioning. Fifty-eight patients with memory deficits, according to subjective complaints or based on clinicians' observations, were assessed with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS). Only 24 of these subjects met the inclusion criteria. Twenty patients took part in the study (four dropped out). All subjects meeting the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria for SZ were maintained on their current antipsychotic medication (18 atypicals and two typicals) and were randomly assigned to treatment with rivastigmine. Dosage was a function of tolerability, beginning at 3 mg/day and progressively increasing to 9 mg/day. Subjects were given the Cambridge Neuropsychological Test Automated Battery (CANTAB) at baseline and 3 and 6 months.

RESULTS

The results revealed no significant improvement in any of the cognitive variables investigated following rivastigmine treatment and symptom severity scores remained unchanged over all recorded time periods.

CONCLUSION

Rivastigmine treatment did not appear to enhance cognition in SZ patients with important cognitive impairments. This finding needs to be interpreted with care and requires substantiation with larger sample size studies with patients treated with cognitive enhancer for longer periods.