1-year follow-up study of cognitive function in first-episode non-affective psychosis

Longitudinal course of core cognitive domains in first-episode acute and transient psychotic disorders compared with schizophrenia

Acute and transient psychotic disorder (ATPD) is characterized by acute onset of psychotic symptoms and early recovery. Contrastingly, schizophrenia (SZ) is a chronic mental disorder characterized by impaired functioning including a deficit in cognition. In SZ, the cognitive deficit is among the core symptoms, but in ATPDs, the existing evidence brings mixed results. Our primary aim was to compare three core cognitive domains (executive functioning/abstraction, speed of processing and working memory) of patients diagnosed with ATPD and SZ over a 12-month period. Moreover, we explored how these diagnostic subgroups differed in their clinical characteristics. We recruited 39 patients with a diagnosis of SZ and 31 with ATPD with schizophrenic symptoms. All patients completed clinical and neuropsychological assessments. At baseline, we used a one-way ANCOVA model with a group as the between-subjects factor. Mixed-model repeated-measures ANOVAs with time as the within-subjects factor and group as the between-subjects factor were run to test the overtime differences. At baseline, we did not find any differences in cognition - with sex, education and age as covariates - between ATPDs and SZ. After one year, all patients showed an improvement in all three domains, however, there were no significant overtime changes between ATPDs and SZ. Regarding clinical profiles, ATPDs demonstrated less severe psychopathology and better functioning compared to SZ both at baseline and after 12 months. The medication dosage differed at retest, but not at baseline between the groups. Our findings suggest clinical differences and a similar trajectory of cognitive performance between these diagnostic subgroups.

The impact of early intervention for first episode psychosis on cognitive functioning

IMPORTANCE

Impaired cognitive functioning is a core characteristic of schizophrenia, present from the onset of the illness and relatively stable thereafter. Despite evidence supporting the impact of early intervention services (EIS) on improving symptoms and functioning in first episode psychosis (FEP), controlled research has not examined its impact on cognitive functioning.

OBJECTIVE

To evaluate the longitudinal course of cognitive functioning in FEP patients participating in a large, controlled study comparing EIS with usual services.

METHODS

A total of 404 persons ages 15-40 years old with non-affective FEP participated in the Recovery After Initial Schizophrenia-Early Treatment Program. A cluster randomized controlled trial was conducted with 34 community mental health treatment centers across the U.S. randomized to provide either an EIS program (NAVIGATE) or usual Community Care (CC) to FEP patients for 2 years. Cognitive functioning was assessed with the Brief Assessment of Cognition in Schizophrenia (BACS) at baseline and 1- and 2-years later.

RESULTS

Older participants (≥20 years old) in both treatment groups improved on all BACS tests. Younger participants (15-19) in NAVIGATE improved significantly more on Digit Sequencing (working memory) than those in CC, whereas both groups improved on most of the other BACS tests. Improvements in cognitive functioning occurred mostly over the first year and were correlated with reductions in symptom severity.

DISCUSSION

EIS do not improve cognitive functioning more than usual care for older FEP patients but may improve working memory in younger FEP patients. Interventions targeting cognition may be required to enhance cognitive functioning in most FEP patients.

Ten-year course of cognition in first-episode non-affective psychosis patients: PAFIP cohort

BACKGROUND

A large body of research states that cognitive impairment in schizophrenia is static. Nevertheless, most previous studies lack a control group or have small study samples or short follow-up periods.

METHOD

We aimed to address these limitations by studying a large epidemiological cohort of patients with first-episode schizophrenia spectrum disorders and a comparable control sample for a 10-year period.

RESULTS

Our results support the generalized stability of cognitive functions in schizophrenia spectrum disorders considering the entire group. However, the existence of a subgroup of patients characterized by deteriorating cognition and worse long-term clinical outcomes must be noted. Nevertheless, it was not possible to identify concomitant factors or predictors of deterioration (all Ps > 0.05).

CONCLUSIONS

Cognitive functions in schizophrenia spectrum disorder are stable; however, a subgroup of subjects that deteriorate can be characterized.

Influence of social cognition as a mediator between cognitive reserve and psychosocial functioning in patients with first episode psychosis

BACKGROUND

Social cognition has been associated with functional outcome in patients with first episode psychosis (FEP). Social cognition has also been associated with neurocognition and cognitive reserve. Although cognitive reserve, neurocognitive functioning, social cognition, and functional outcome are related, the direction of their associations is not clear. Therefore, the main aim of this study was to analyze the influence of social cognition as a mediator between cognitive reserve and cognitive domains on functioning in FEP both at baseline and at 2 years.

METHODS

The sample of the study was composed of 282 FEP patients followed up for 2 years. To analyze whether social cognition mediates the influence of cognitive reserve and cognitive domains on functioning, a path analysis was performed. The statistical significance of any mediation effects was evaluated by bootstrap analysis.

RESULTS

At baseline, as neither cognitive reserve nor the cognitive domains studied were related to functioning, the conditions for mediation were not satisfied. Nevertheless, at 2 years of follow-up, social cognition acted as a mediator between cognitive reserve and functioning. Likewise, social cognition was a mediator between verbal memory and functional outcome. The results of the bootstrap analysis confirmed these significant mediations (95% bootstrapped CI (-10.215 to -0.337) and (-4.731 to -0.605) respectively).

CONCLUSIONS

Cognitive reserve and neurocognition are related to functioning, and social cognition mediates in this relationship.

Global and Specific Profiles of Executive Functioning in Prodromal and Early Psychosis

Objective: Numerous reports on neurocognitive functioning deficits in individuals at clinical high risk (CHR) and first-episode psychosis (FEP) patients suggest particular deficits in executive functioning (EF). However, to date, most of the studies have administered a single or a few EF tests to participants, and few investigations have examined the different components of EF to identify specific subdomains of relative strength and weakness. Method: Forty CHR subjects, 85 FEP patients, and 85 healthy controls (HCs) were assessed with a neuropsychological battery to elucidate the profiles of EF in the subdomains of shift, attention, fluency, and planning. Results: In the subdomains of shift, attention, and fluency, CHR individuals and FEP patients showed deficits compared to HC. The post hoc analysis revealed that CHR individuals had comparable attention shifting and phonemic fluency compared to FEP. CHR showed intermediate deficits between FEP and HCs in spatial working memory and semantic fluency, and the largest effect size was observed in semantic fluency both for CHR and FEP. Conclusion: Overall, the findings of this study, in addition to providing detailed profiles of EF in prodromal and early psychosis patients, highlight the informative value of the specific subdomains of semantic fluency and spatial working memory.

Details of attention and learning change in first-episode schizophrenia

Impaired attention and learning functions are common in schizophrenia. The details of this impairment, and how these change across time, are not well known. We aimed to compare the parameters of well-known attention and learning neuropsychological tests in first-episode schizophrenia (FES) patients and healthy controls in a 2-year follow-up period. The performance of 28-25 FES patients and pairwise matched healthy controls on the Continuous Performance Test-Identical Pairs, the revised Hopkins Verbal Learning Test, and the revised Brief Visuospatial Memory Test was compared at baseline and 2 years later. The attention dysfunction of the FES group was driven by slow reaction time and a comparative failure to identify correct hits. The reaction time was reduced somewhat across time in the patient group. Regarding the learning tasks, both groups increased their number of correct answers across trials. However, at each trial, the patient group exhibited lower scores, with a trend towards better visual learning performance across time. In summary, the FES patients were impaired in most of the parameters of the attention and learning tasks. Across time, modest improvements in reaction time and visual learning were displayed in the FES group. However, this group never caught up with the control group.

The course of cognitive functioning after first-episode of psychosis: A six month follow-up study

Our aim with the present study was to evaluate rank-order and mean-level cognitive functioning stability among first-episode psychosis (FEP) patients, measured using the Cambridge Neuropsychological Test Automated Battery (CANTAB), over a six month period. We also aimed to examine longitudinal measurement invariance and identify factors-such as age, gender, educational level, treatment and psychopathological change scores-potentially linked to cognitive change among patients. In addition, correlations between objectively measured and subjectively evaluated cognitive functioning were estimated. Neuropsychological assessments were administered to 85 patients after the initial stabilisation of their psychosis; 82 of the patients were retested. Subjectively perceived cognitive functioning was measured using a subscale derived from the Estonian version of the Subjective Well-Being Under Neuroleptic Scale (SWN-K-E). On average, executive functioning and processing speed improved significantly, while memory test scores decreased significantly, over time. Very high rank-order stability (r=0.80 to 0.94, p<0.001) was observed with all measured ability scores. Confirmatory factor analysis revealed the loadings of a single (broad ability) factor model were equal across both measurement occasions, but the lack of intercept invariance suggested that mean-level comparisons are more appropriately carried out at a subtest level. On average psychopathology scores and antipsychotics doses declined over time, with the latter also significantly correlating with better executive functioning. Gender was a significant moderator of some domains of cognitive performance, and decline tended to be somewhat more pronounced for women. The results also indicated the lack of any relationship between objective and subjective measurements of cognitive functioning.

Longitudinal changes in prospective memory and their clinical correlates at 1-year follow-up in first-episode schizophrenia

This study aimed to investigate prospective memory (PM) and the association with clinical factors at 1-year follow-up in first-episode schizophrenia (FES). Thirty-two FES patients recruited from a university-affiliated psychiatric hospital in Beijing and 17 healthy community controls (HCs) were included. Time- and event-based PM (TBPM and EBPM) performances were measured with the Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) at baseline and at one-year follow-up. A number of other neurocognitive tests were also administered. Remission was determined at the endpoint according to the PANSS score ≤ 3 for selected items. Repeated measures analysis of variance revealed a significant interaction between time (baseline vs. endpoint) and group (FES vs. HCs) for EBPM (F(1, 44) = 8.8, p = 0.005) and for all neurocognitive components. Paired samples t-tests showed significant improvement in EBPM in FES (13.1±3.7 vs. 10.3±4.8; t = 3.065, p = 0.004), compared to HCs (15.7±3.6 vs. 16.5±2.3; t = -1.248, p = 0.230). A remission rate of 59.4% was found in the FES group. Analysis of covariance revealed that remitters performed significantly better on EBPM (14.9±2.6 vs. 10.4±3.6; F(1, 25) = 12.2, p = 0.002) than non-remitters at study endpoint. The association between EBPM and 12-month clinical improvement in FES suggests that EBPM may be a potential neurocognitive marker for the effectiveness of standard pharmacotherapy. Furthermore, the findings also imply that PM may not be strictly a trait-related endophenotype as indicated in previous studies.

Cognitive control deficit in patients with first-episode schizophrenia is associated with complex deviations of early brain development

BACKGROUND

Several clinical and radiological markers of early neurodevelopmental deviations have been independently associated with cognitive impairment in patients with schizophrenia. The aim of our study was to test the cumulative and/or interactive effects of these early neurodevelopmental factors on cognitive control (CC) deficit, a core feature of schizophrenia.

METHODS

We recruited patients with first-episode schizophrenia-spectrum disorders, who underwent structural MRI. We evaluated CC efficiency using the Trail Making Test (TMT). Several markers of early brain development were measured: neurological soft signs (NSS), handedness, sulcal pattern of the anterior cingulate cortex (ACC) and ventricle enlargement.

RESULTS

We included 41 patients with schizophrenia in our analysis, which revealed a main effect of ACC morphology (p = 0.041) as well as interactions between NSS and ACC morphology (p = 0.005), between NSS and handedness (p = 0.044) and between ACC morphology and cerebrospinal fluid (CSF) volume (p = 0.005) on CC measured using the TMT-B score - the TMT-A score.

LIMITATIONS

No 3- or 4-way interactions were detected between the 4 neurodevelopmental factors. The sample size was clearly adapted to detect main effects and 2-way interactions, but may have limited the statistical power to investigate higher-order interactions. The effects of treatment and illness duration were limited as the study design involved only patients with first-episode psychosis.

CONCLUSION

To our knowledge, our study provides the first evidence of cumulative and interactive effects of different neurodevelopmental markers on CC efficiency in patients with schizophrenia. Such findings, in line with the neurodevelopmental model of schizophrenia, support the notion that CC impairments in patients with schizophrenia may be the final common pathway of several early neurodevelopmental mechanisms.

Parental socioeconomic status and prognosis in individuals with ultra-high risk for psychosis: A 2-year follow-up study

A possible relationship between socioeconomic status (SES) and the development of mental illness has been continuously suggested. Still, less clear is whether the SES has a direct effect on the development of schizophrenia. In this longitudinal study, we test the hypothesis that parental SES is associated with the prognosis of individuals at ultra-high risk (UHR) for psychosis. One hundred and sixteen individuals who were determined as UHR using a Comprehensive Assessment of At-Risk Mental States (CAARMS) were classified into three groups based on the parental SES levels assessed by the Hollingshead-Redlich scale. There were no differences in the Positive and Negative Syndrome Scale (PANSS), the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS) and the Brief Psychiatric Rating Scale (BPRS) at baseline. However, at the 1-year follow-up, the higher versus lower SES group showed significant differences in clinical measures including SAPS, SANS, PANSS positive and negative scales as well as BPRS scores. Most of these clinical differences were attenuated by the second year of follow-up with no sign of an increased rate of conversion to psychosis derived from a socioeconomically disadvantaged status. However, SAPS and PANSS positive scale still revealed sub-threshold positive symptoms within the low SES group at the 2-year follow-up. Moreover, especially for the subjects who continued the follow-ups for 1year and/or 2years, the changes of clinical symptoms between the baseline and follow-ups showed that there were significant symptom changes in higher and middle SES groups within the 1-year period already, but the lower SES group showed significant recovery at the second year. Our findings suggest that low parental SES can be detrimental to the prognosis phase of individuals at UHR. Limited supportive socioeconomic resources may slow the rate of symptom recovery in UHR subjects.

Stability of executive functions in first episode psychosis: One year follow up study

Executive functioning is a multi-dimensional construct covering several sub-processes. The aim of this study was to determine whether executive functions, indexed by a broad range of executive measures remain stable in first episode psychosis (FEP) over time. Eighty-two patients and 107 age and gender matched healthy controls were assessed on five subdomains of executive functioning; working memory, fluency, flexibility, and inhibitory control at baseline and at 1 year follow-up. Results showed that patients performed significantly poorer than controls on all executive measures at both assessment points. In general executive functions remained stable from baseline to follow-up, although both groups improved on measures of inhibitory control and flexibility. In phonemic fluency, controls showed a slight improvement while patients showed a slight decline. Investigation of individual trajectories revealed some fluctuations in both groups over time, but mainly supports the group level findings. The implications of these results are discussed.

Effect of time and duration of untreated psychosis on cognitive and social functioning in Chinese patients with first-episode schizophrenia: A 1-year study

BACKGROUND

Duration of untreated psychosis (DUP) is believed to exert a deleterious effect on cognitive and social function. However, to date, results remain inconclusive.

AIMS

To investigate the effect of time and DUP on cognitive and social functioning in first-episode schizophrenia (FES) subjects in Shanghai, China.

METHODS

FES patients were subjected to a comprehensive neuropsychological battery, the Personal and Social Performance scale (PSP) and the Positive and Negative Symptoms Scale (PANSS) at baseline, 6 month and 1 year. DUP was defined as the time from onset of first psychotic symptoms to first contact made with psychiatric services.

RESULTS

Though the rate of non-completers in our observational study was relatively high (40%), we did not find any significant differences between the completers and non-completers (P-values > 0.05). Significant impairments in verbal learning and memory and executive function were noted over the course of 1 year. Meanwhile, social function improved significantly over the course of 1 year. Although, DUP did not share any significant relationship with cognitive or social function the effect estimate (range: - 0.03 to 0.02) of an increase of 1 month in DUP was clinically non-negligible in this study.

CONCLUSIONS

In Chinese FES patients, the longitudinal course of cognitive function tends to worsen in verbal learning and memory, executive function and motor speed, while that of social function tends to improve. DUP was not found to be associated with cognitive or social deterioration in Chinese FES.

The MATRICS Consensus Cognitive Battery (MCCB): performance and functional correlates

Neurocognitive impairment is a core feature in psychotic disorders and the MATRICS Consensus Cognitive Battery (MCCB) is now widely used to assess neurocognition in this group. The MATRICS has been translated into several languages, including Norwegian; although this version has yet to be investigated in an adult clinical population. Further, the relationship between the MATRICS and different measures of functioning needs examination. The purpose of this study was to describe neurocognition assessed with the Norwegian version of the MATRICS battery in a sample of patients with psychotic disorders compared to age and gender matched healthy controls and to examine the association with educational-, occupational- and social-functioning in the patient group. One hundred and thirty one patients and 137 healthy controls completed the battery. The Norwegian version of the MATRICS was sensitive to the magnitude of neurocognitive impairments in patients with psychotic disorders, with patients displaying significant impairments on all domains relative to healthy controls. Neurocognition was also related to both self-rated and objective functional measures such as social functioning, educational- and employment-history.

Meta-analysis of cognitive deficits in ultra-high risk to psychosis and first-episode psychosis: do the cognitive deficits progress over, or after, the onset of psychosis?

Cognitive dysfunction is a well-established feature of schizophrenia, and there is evidence suggesting that cognitive deficits are secondary to abnormal neurodevelopment leading to problems in acquiring such abilities. However, it is not clear whether there is also a decline in cognitive performance over, or after, the onset of psychosis. Our objective was to quantitatively examine the longitudinal changes in cognitive function in patients who presented with first-episode psychosis (FEP), ultra-high risk (UHR) for psychosis, and controls. Electronic databases were searched for the studies published between January 1987 and February 2013. All studies reporting longitudinal cognitive data in FEP and UHR subjects were retrieved. We conducted meta-analyses of 25 studies including 905 patients with FEP, 560 patients at UHR, and 405 healthy controls. The cognitive performances of FEP, UHR, and healthy controls all significantly improved over time. There was no publication bias, and distributions of effect sizes were very homogenous. In FEP, the degree of improvement in verbal working memory and executive functions was significantly associated with reduction in negative symptoms. There was no evidence of cognitive decline in patients with UHR and FEP. In contrast, the cognitive performances of both groups improved at follow-up. These findings suggest that cognitive deficits are already established before the prodromal phases of psychosis. These data support the neurodevelopmental model rather than neurodegenerative and related staging models of schizophrenia.

Apathy, poor verbal memory and male gender predict lower psychosocial functioning one year after the first treatment of psychosis

BACKGROUND

Apathy is a negative symptom associated with poor psychosocial functioning in schizophrenia but has not been sufficiently studied as predictor of poor functioning in first episode psychosis (FEP).

OBJECTIVE

The main aim of the current study was to evaluate if apathy predicts poor functioning after 1 year in FEP patients in the context of other clinical variables with influence on outcome.

METHOD

Sixty-four FEP patients completed an extensive clinical and neuro-psychological test battery at baseline and 1-year follow-up. Symptoms were assessed with the Positive and Negative Syndrome scale (PANSS), apathy with the shortened Apathy Evaluation Scale (AES-C-12) and psychosocial functioning with the functioning score from the split version of the Global Assessment of Functioning scale (GAF-F).

RESULTS

High levels of apathy, poor verbal memory and being male were the baseline variables that best predicted poor functioning at 1-year follow-up, explaining 34% of the variance in GAF-F. When PANSS negative factor was included in the analysis, the significance of AES-C-12 diminished.

CONCLUSION

These findings points to a robust role for apathy among the negative symptoms in the development of persisting psychosocial dysfunction in FEP and supports the current effort in targeting motivation to improve functioning.

The relevance of cognitive, clinical and premorbid variables in predicting functional outcome for individuals with first-episode psychosis: a 3 year longitudinal study

Real-world functional deficits are common and persistent in individuals with psychosis. Cognitive deficits have been shown to compromise functioning. We aimed to study the predictive values of premorbid, sociodemographic, and baseline clinical and neurocognitive factors on long-term functional outcome for individuals with first episode non-affective psychosis. We failed to demonstrate a significant relationship between cognitive deficits at baseline and functional disability at 3 year follow-up. Diagnosis of schizophrenia (OR=2.457, p=0.011), shorter education (OR=1.177, p=0.005) and poor premorbid social adjustment (OR=1.628, p=0.013) emerged as the strongest predictors for the 114 subjects (56%) that exhibited functional disability at 3-year follow-up. A considerable proportion of the variance in functioning (74% at 1 year and 77% at 3 year) remained unexplained by baseline variables. The set of variables that predicted functional outcome at medium- (1 year) and long-term (3 years) differed. In conclusion, the length of follow-up influenced the relationship between baseline variables and functional outcome. A substantial proportion of the variance in function was not explained by these variables and therefore the influence of other factors warrants further investigation. The data support the notion that premorbid social adjustment is an important aspect in functional outcome over the course of the illness.

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.

Logic and justification for dimensional assessment of symptoms and related clinical phenomena in psychosis: relevance to DSM-5

Work on the causes and treatment of schizophrenia and other psychotic disorders has long recognized the heterogeneity of the symptoms that can be displayed by individuals with these illnesses. Further, researchers have increasingly emphasized the ways in which the severity of different symptoms of this illness can vary across individuals, and have provided evidence that the severity of such symptoms can predict other important aspects of the illness, such as the degree of cognitive and/or neurobiological deficits. Additionally, research has increasingly emphasized that the boundaries between nosological entities may not be categorical and that the comorbidity of disorders may reflect impairments in common dimensions of genetic variation, human behavior and neurobiological function. As such, it is critical to focus on a dimensional approach to the assessment of symptoms and clinically relevant phenomena in psychosis, so as to increase attention to and understanding of the causes and consequences of such variation. In the current article, we review the logic and justification for including dimensional assessment of clinical symptoms in the evaluation of psychosis in the Fifth Edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM-5).

Course of cognitive deficits in first episode of non-affective psychosis: a 3-year follow-up study

Cognitive dysfunctions are critical determinants of the quality of life and functionality in schizophrenia. Whether the cognitive deficits present at an early stage, are static or change across one's lifespan is still under debate. This study aims to investigate the long-term (3 years) course of cognitive deficits in a large and representative cohort of first episode schizophrenia spectrum patients (N=155),and evaluate their influence on disability. In addition, a healthy control sample (N=43) was also studied for comparison. This study evaluates the performance of patients and controls in a battery of cognitive assessments using baseline, 1-year and 3-year follow-up designs. The results show that, although cognitively outperformed by the controls at any time, the cognitive performance of the patients improved similar to the controls in all cognitive functions except verbal and visual memory. Even though the course of cognitive performance across the sample as a whole was stable, the subgroup of patients who experienced a cognitive decline had worse functionality and lesser amelioration of negative symptoms. Overall, there is no significant deterioration in the cognitive function in a group of first episode schizophrenia spectrum disorder patients, with the possible exception of tasks that were associated with episodic memory. However, patients whose cognitive performance demonstrated a declining trend may present with a poorer progression in terms of clinical and disability variables.

Neurocognitive development in first episode psychosis 5 years follow-up: associations between illness severity and cognitive course

Cognitive deficits are documented in first-episode psychosis (FEP), but the continuing course is not fully understood. The present study examines the longitudinal development of neurocognitive function in a five year follow-up of FEP-patients, focusing on the relation to illness severity, as measured by relapses and diagnostic subgroups. The study is an extension of previous findings from the TIPS-project, reporting stability over the first two years. Sixty-two FEP patients (53% male, age 28 ± 9 years) were neuropsychologically examined at baseline and at 1, 2, and 5 year follow-ups. The test battery was divided into five indices; Verbal Learning, Executive Function, Impulsivity, Motor Speed, and Working Memory. To investigate the effect of illness severity, the sample was divided in groups based on number of relapses, and diagnostic subgroups, respectively. Impulsivity and Working Memory improved significantly in the first two years, followed by no change over the next three years. Motor Speed decreased significantly from 2 to 5 years. Number of relapses was significantly related to Verbal Learning and Working Memory, showing a small decrease and less improvement, respectively, in patients with two or more episodes. No significant association was found with diagnostic group. Neurocognitive stability as well as change was found in a sample of FEP-patients examined repeatedly over 5 years. Of potential greater importance for understanding how psychotic illnesses progress, is the finding of significant associations between neurocognition and number of relapses but not diagnostic group, indicating that neurocognition is more related to recurring psychotic episodes than to the descriptive diagnosis per se.

Working memory as a predictor of negative symptoms and functional outcome in first episode psychosis

The relationship of neurocognitive course with clinical and functional outcomes in psychosis is not well known, especially in the long term. The aim of the study was to examine the clinical and neuropsychological course of first-episode psychosis patients at 5-year follow-up and analyze the relationship of cognitive performance with clinical and functional outcome. The 5-year follow-up was conducted with 26 first-episode psychosis patients. Psychotic symptoms were measured by the Positive and Negative Syndrome Scale, manic and depressive symptoms by the Young Mania Rating Scale and Hamilton Depression Rating Scale respectively, and psychosocial functioning by the Functioning Assessment Short Test. The cognitive domains were assessed by the Wechsler Adult Intelligence Scale, the Wisconsin Card Sorting Test, the Trail Making Test, the Verbal Fluency Test, the Stroop Colour-Word Test and the Wechsler Memory Scale. Patients showed symptomatic improvement in the follow-up except in negative psychotic symptoms. There was also improvement in most cognitive domains except in working memory and processing speed in the follow-up. Working memory impairment was associated to negative psychotic symptoms and poor functional outcomes. Negative symptoms mediated the relationship between working memory and outcome. Therefore, negative symptoms should be a primary target of treatment to improve functional outcomes.

Negative symptoms and executive function in schizophrenia: does their relationship change with illness duration?

BACKGROUND

Negative symptoms and cognitive dysfunction are of crucial functional and prognostic importance in schizophrenia. However, the nature of the relationship between them and the factors that may influence it have not been well established.

AIMS

To investigate whether the relationship between negative symptoms and executive function changes according to the duration of illness in schizophrenia.

METHODS

The Positive and Negative Syndrome Scale was used to assess psychopathology and the Wisconsin Card Sorting Test (WCST) to evaluate executive function in a sample of 200 schizophrenic patients who were classified in 3 groups according to their duration of illness: up to 5 years (short duration group), 6-20 years (intermediate duration group) and over 20 years of illness (long duration group).

RESULTS

Medium-sized correlations were found between negative symptoms and WCST performance as assessed by the number of completed categories in all 3 groups. However, differences were found according to the duration of schizophrenia. For patients in the short duration group, negative symptoms correlated with WCST nonperseverative errors, but for those in the long duration group the correlation was with perseverative errors.

CONCLUSION

We found a differential relationship between negative and cognitive symptoms in different stages of schizophrenia. Illness duration should be considered when studying the relationship between negative symptoms and cognition.

Identifying attentional deficits in people with first-episode psychosis with the Scale for the Assessment of Negative Symptoms attention subscale: is it possible?

OBJECTIVE

The aim of this study was to examine the correspondence between clinical ratings of inattention problems in the early course of a psychotic disorder and concurrent neuropsychological data for sustained attention and speed of processing/executive functioning (SP/EF) derived from a comprehensive neuropsychological test battery.

METHOD

A sample of 131 patients with first-episode psychosis (FEP) was clinically rated after clinical stabilization with the attention subscale of the Scale for the Assessment of Negative Symptoms (SANS) and a completed neuropsychological test battery, which included measurements of sustained attention and SP/EF. To test the associations of the clinical ratings and objective data, correlations and regression analyses were conducted.

RESULTS

Clinical ratings of inattention showed only weak correlations with the global score of SP/EF and with the clinical ratings of negative symptoms (ρ < 0.25). None of the independent variables entered in the logistic regression model were significant (all P values > .05). Percentages of agreement between clinical judgment and neuropsychological measures were unacceptably low (ranged from 53% to 68%). κ values indicate only slight agreement (κ < 0.2).

CONCLUSIONS

Clinical ratings based on the SANS attention subscale do not reliably match neuropsychological test measures of attention or other related cognitive processes in FEP. Even for those cognitive domains more pronouncedly impaired, mental health professionals will likely need to rely on psychometric testing or, alternatively, specific guidelines and also, probably, to collect data from different sources to adequately identify cognitive impairments.

Intact relational memory and normal hippocampal structure in the early stage of psychosis

BACKGROUND

Previous studies indicate that the transition to psychosis is associated with dynamic changes of hippocampal integrity. Here we explored hippocampal volume and neural activation during a relational memory task in patients who were in the early stage of a psychotic illness.

METHODS

Forty-one early psychosis patients and 34 healthy control subjects completed a transitive inference (TI) task used previously in chronic schizophrenia patients. Participants learned to select the "winner" of two sets of stimulus pairs drawn from an overlapping sequence (A > B > C > D > E) and a nonoverlapping set (a > b, c > d, e > f, g > h). During a functional magnetic resonance imaging scan, participants were tested on the trained pairs and made inferential judgments on novel pairings that could be solved based on training (e.g., B vs. D). Hippocampal volumes were manually segmented and compared between groups. Functional magnetic resonance imaging analyses included 27 early psychosis patients and 30 control subjects who met memory training criteria.

RESULTS

Groups did not differ on inference performance or hippocampal volume and exhibited similar activation of medial temporal regions when judging nonoverlapping pairs. However, patients who failed to meet memory training criteria had smaller hippocampal volumes. Neural activity during TI was less widespread in early psychosis patients, but between-group differences were not significant. Hippocampal activity during TI was positively correlated with inference performance only in control subjects.

CONCLUSIONS

Our results provide evidence that relational memory impairment and hippocampal abnormalities, well established in chronic schizophrenia, are not fully present in early psychosis patients. This provides a rationale for early intervention, targeting the possible delay, reduction, or prevention of these deficits.

[Schizophrenia, executive control and memory]

Schizophrenia affects 1% of the general population. In addition to disabling clinical symptoms, cognitive deficits have also been updated. It has further been proposed that the well-known diversity of schizophrenia in terms of functional outcome and recovery from acute episode is best characterized by cognitive deficits, but not by its classical symptoms. DSM-V acknowledges the importance of cognition in schizophrenia, and could recommend a formal neuropsychological assessment in individuals with psychosis. Schizophrenic patient's cognitive functioning has been studied extensively in the domain of memory and executive control. To date, the studies highlight important deficits in both of these domains. However, within the memory systems, some of them remain unaffected. Altogether, the data invalidate the hypothesis of a global damage and are in favor of specific cognitive deficits. The observed deficits would depend on the dominant symptoms and pre-morbid functioning. The interest of these results was to give impulse to the development of comprehensive assessment battery designed to evaluate the cognitive profiles of each patient and develop a personalized program of cognitive remediation.

Neurocognition and occupational functioning in patients with first-episode psychosis: a 2-year follow-up study

Neurocognitive deficits are a core feature of schizophrenia that is associated with poor occupational functioning. Few studies have investigated this relationship in patients with first-episode psychosis. The current study examined the characteristics of employed and unemployed patients with first-episode psychosis at baseline and 2-year follow-up, and the predictive value of neurocognition on employment status. One-hundred and twenty-two first-episode psychosis patients were assessed with clinical and neurocognitive measures at baseline. Occupational status was assessed at baseline and 2-year follow-up. Those unemployed at baseline were rated lower on global functioning and were more likely to have a schizophrenia spectrum disorder. Total employment rates were 41% at baseline and 38% at 2-year follow-up. Four employment paths emerged at follow-up, defined as persistently employed, becoming unemployed, entering employment and persistently unemployed. The persistently employed group had the highest global functioning score. For the total sample, baseline employment status and sustained attention predicted employment status at follow-up. For those employed at baseline, better sustained attention, higher global functioning, more positive symptoms and less alcohol use predicted persistent employment at follow-up. For those unemployed at baseline, none of the variables predicted change in employment status. Implications of these results are discussed.

Insight dimensions in first-episode psychosis patients: clinical, cognitive, pre-morbid and socio-demographic correlates

AIM

To investigate pre-morbid, socio-demographic, clinical and cognitive variables as predictors of insight in a large and representative sample of first-episode psychosis patients.

METHODS

The abbreviated Scale to Assess Unawareness of Mental Disorder was used to assess insight dimensions. Patients with good and poor insight were independently compared on insight dimensions and logistic regression analyses were conducted to identify explanatory variables associated with each insight dimension.

RESULTS

The patients with good and poor insight of having a mental disorder differed in duration of untreated psychosis, diagnosis and attention, but only attention appeared as a predictor. The insight of the need for medication groups showed differences in age of onset, depression, severity of disorganized symptoms and hospitalization rate.Nevertheless, age of onset and disorganized symptoms seem to be the predictors. Groups of insight of the social consequences differed in duration of untreated psychosis, the negative and disorganized symptoms severity, disability, education, diagnosis and hospitalization rate.However, exclusively, the severity of disorganized symptoms seems to predict insight of social consequences.

CONCLUSION

When independently analysed, the three insight dimensions showed different rates of affectation and different predictors. These results suggest that there must be different mechanisms underlying the lack of insight. First-episode psychosis is a crucial period for treatment adherence formation, an issue strongly associated with good insight. Thus, a more accurate evaluation of the predictors of lack of insight into each dimension is warranted to achieve a better comprehension of the lack of insight in schizophrenia and in turn, to implement treatment programmes seeking to improve it.

Longitudinal studies of cognition in first episode psychosis: a systematic review of the literature

Although cognitive deficits are recognized as a core feature in schizophrenia, their evolution over the course of the illness is still debated. Longitudinal studies of cognition in patients after a first episode of psychosis (FEP) provide extremely useful information, in that they include an adequate and realistic baseline measure of cognitive performance, while at the same time minimizing the effect of confounding variables associated with chronicity. The aim of this systematic review was to summarize findings of studies assessing the longitudinal course of neuropsychological deficits in patients with FEP for durations of at least one year. Overall, the neuropsychological deficits that are present following a first episode of psychosis appeared to remain stable over time for periods of up to ten years, the only possible exception being verbal memory deficits, where there is some evidence of further deterioration over the long term. However, further studies are needed to confirm this conclusion, especially in the (somewhat inconsistently defined) domain of executive function. Improvements in psychopathology appear to positively influence the course of cognitive deficits, although the effects of antipsychotic medication are not as clear.

A digit symbol coding task as a screening instrument for cognitive impairment in first-episode psychosis

Cognitive impairment may be detected largely by examining the performance on a single neuropsychological measure. The purpose of the present study was to evaluate the validity and diagnostic accuracy of a coding task in comparison with other related tasks. One hundred thirty-one first-episode psychosis patients were administered five cognitive tasks related to a "speed of processing and executive functioning" dimension (Digit Symbol, Trail Making Test [TMT] parts A and B, Cancellation Test, and Digit Span-backward) and an additional measure of functional outcome. Digit Symbol provided good indices of accuracy and correlations with the global composite score of a comprehensive neuropsychological assessment represented large effect sizes. Correlations with a functional outcome were modest. Similar results were observed with the TMT. The processing speed, as measured by Digit Symbol, may be particularly good in capturing the generalized dysfunction which may be causing the widespread cognitive failures in schizophrenia spectrum disorders.

Cannabis use and cognitive functioning in first-episode schizophrenia patients

Cannabis is one of the most widely used illicit drugs in the world. In healthy individuals cannabis is associated with cognitive impairments. Research into the effect of cannabis use in schizophrenia has yielded contradictory findings. Our aim has been to explore the correlates of cannabis use in cognitive and psychopathological features, both cross-sectional and longitudinally, in early phases of schizophrenia. 104 patients with a first episode of non-affective psychosis and 37 healthy controls were studied. Patients were classified according to their use of cannabis prior to the onset of the illness (47 users vs. 57 non-users). They were cross-sectionally and longitudinally studied and compared on clinical and cognitive variables and also on their level of premorbid adjustment. Cannabis user patients had better attention and executive functions than non-cannabis user patients at baseline and after 1 year of treatment. Both groups showed similar improvement in their cognitive functioning during the 1-year follow-up period. We also found that users had a better social premorbid adjustment, particularly during the early periods of life. The amount of cannabis consumed and the length of time of consumption did not significantly relate to cognitive performance. The use of cannabis does not seem to be associated with a negative effect on cognition in a representative sample of first-episode schizophrenia patients. Cannabis user patients appear to comprise a subgroup of patients with a better premorbid adjustment and premorbid frontal cognitive functions.

Short term neurocognitive effects of treatment with ziprasidone and olanzapine in recent onset schizophrenia

BACKGROUND

Cognitive deficits are a core feature in schizophrenia. Cognitive deficits appear to be present at the onset of schizophrenia and persist after remission of psychotic symptoms. As cognitive deficits are associated with poor functional outcome, they form an important focus of treatment. There are relatively few head-to-head comparisons of the effects of second generation antipsychotics on cognition in recent onset schizophrenia. This is the first study to compare the effects of a short term treatment of olanzapine versus ziprasidone on cognitive functioning in recent onset schizophrenia. An earlier study conducted in chronic patients revealed an enhancement of cognition after treatment for both agents, but the extent of improvement was not significantly different between ziprasidone and olanzapine.

METHOD

Patients with recent onset schizophrenia with limited previous exposure to medical treatment underwent a double blind randomized controlled treatment trial. Fifty-six patients completed the neuropsychological testing procedure prior to randomization and after eight weeks of treatment and were included in the analysis. We tested cognitive functioning in general and verbal memory in particular. We calculated a single unweighted composite score based on nine cognitive tests to determine general cognitive functioning.

RESULTS

Cognition appeared enhanced after treatment, but was not significantly different between treatment groups, neither for the verbal memory measures, nor for the neurocognitive composite score. Furthermore, cognitive enhancement did not correlate to clinical improvement.

CONCLUSION

Cognitive deficits are not a reason for preferentially prescribing one of the two second generation antipsychotics tested over the other.

First-episode schizophrenia patients neuropsychologically within the normal limits: evidence of deterioration in speed of processing

In apparent contradiction to the notion of cognitive impairment as a core feature of schizophrenia, some studies have described a subgroup of patients neuropsychologically within normal limits. It remains to be determined whether this subgroup has intact cognitive functioning or a higher premorbid functioning that attenuates the evidence of deterioration. Out of a total of 111 patients with FES or schizophreniform disorder, 25 (23%) were classified as cognitive normal (CN) according to criteria based on performance in six basic cognitive dimensions and an overall composite score, and their cognitive profile was compared with that of 28 controls. The CN subgroup had better social premorbid adjustment and had a higher premorbid IQ than the cognitive impaired subgroup. There were no differences in the other pretreatment variables examined. The CN subgroup performed similarly to controls in the cognitive dimensions, including sustained attention, verbal memory and executive functions. These profiles remained mostly unaltered after controlling for premorbid IQ. The cognitive deterioration index, calculated by ratio of performance in general knowledge and vocabulary abilities to a measure of processing speed , showed that both patient subgroups had similar levels of deterioration and that this was significantly different to that of controls. Although FES patients performed within normal limits and better than cognitive impaired patients in a processing speed task, they did nevertheless display a pattern of deterioration in processing speed (in relation to their premorbid IQ) equivalent to that of those with marked impairments.

Neuropsychological abnormalities in schizophrenia and major mood disorders: similarities and differences

The past 20 years have been witness to a growing knowledge base of research highlighting the critical importance of cognition in understanding functional status and outcome in schizophrenia. This work has led to an increased emphasis on identifying and evaluating treatments that enhance cognition in schizophrenia, with the hope that this would translate into a better quality of life and improved outcome for patients. At the same time, this research has raised new questions about the specificity of cognitive impairments to schizophrenia and the degree to which similar cognitive impairments may be present in other disorders that can involve psychotic symptoms (eg, schizoaffective disorder, bipolar disorder, and psychotic major depression). This article provides a brief overview of work comparing cognitive function across the nonaffective and affective psychoses and highlights areas of similarity and dissimilarity in the role cognition plays in these disorders.

Construct validity of the Trail Making Test: role of task-switching, working memory, inhibition/interference control, and visuomotor abilities

The aim of this study was to clarify which cognitive mechanisms underlie Trail Making Test (TMT) direct and derived scores. A comprehensive review of the literature on the topic was carried out to clarify which cognitive factors had been related to TMT performance. Following the review, we explored the relative contribution from working memory, inhibition/interference control, task-switching ability, and visuomotor speed to TMT performance. Forty-one healthy old subjects participated in the study and performed a battery of neuropsychological tests including the TMT, the Digit Symbol subtest [Wechsler Adult Intelligence Scale (Third Version) (WAIS-III)], a Finger Tapping Test, the Digits Forward and Backward subtests (WAIS-III), Stroop Test, and a task-switching paradigm inspired in the Wisconsin Card Sorting Test. Correlation and regression analyses were used in order to clarify the joint and unique contributions from different cognitive factors to the prediction of TMT scores. The results suggest that TMT-A requires mainly visuoperceptual abilities, TMT-B reflects primarily working memory and secondarily task-switching ability, while B-A minimizes visuoperceptual and working memory demands, providing a relatively pure indicator of executive control abilities.

Cognitive remediation for schizophrenia: it is even more complicated

PURPOSE OF REVIEW

Attempts to remediate the cognitive difficulties of people with a diagnosis of schizophrenia have shown efficacy; however, existing treatment studies display huge variation, frustrating efforts to determine how best to apply this treatment tool. This review summarizes findings of induced cognitive change in schizophrenia, with reference to the remediation method, the presence of accompanying treatment(s), how cognitive change generalizes and its value.

RECENT FINDINGS

Although there is strong evidence that cognitive change can be induced in schizophrenia, there is little evidence for the superiority of any treatment approach. Furthermore, remediation is most effective when in combination with other treatments, such as vocational training. Cognitive rehabilitation can be cost-effective and is valued by patients. A number of studies show generalization of positive outcomes beyond cognitive variables, with more focused treatment associated with less generalization.

SUMMARY

Induced cognitive change does not necessarily need to be large to facilitate functional outcomes. Instead, opportunities to apply newly acquired cognitive skills and strategies in the real world are vital. The next generation of studies need to compare different treatments using specific and more general measures of cognitive outcome. These may then throw light on their mechanisms of action. The results of these more sophisticated studies will allow therapists to tailor treatments to individuals to maximize gain for patients.