Changes in cognitive functioning following comprehensive treatment for first episode patients with schizophrenia spectrum disorders

Association between the HHEX polymorphism and delayed memory in first-episode schizophrenic patients

The hematopoietically-expressed homeobox gene (HHEX) played a critical role in regulating the immune system that the abnormality of which was involved in the psychopathology and cognitive deficits of psychiatric disorders. The aim of this study was to investigate the effect of HHEX rs1111875 polymorphism on the susceptibility and cognitive deficits of first-episode schizophrenic patients (FSP). We assessed cognitive function in 239 first-episode patients meeting DSM-IV for schizophrenia, and 368 healthy controls using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The HHEX rs1111875 polymorphism was genotyped. Our results showed that the allelic and genotypic frequencies of HHEX rs1111875 polymorphism didn't differ between FSP and healthy controls (both p > 0.05) after adjusting for sex and age. Cognitive test scores in FSP were significantly lower than those in healthy controls on all scales (all p < 0.001) except for the visuospatial/constructional score (p > 0.05) after adjusting for covariates. There was a significant genotype (p < 0.05) rather than genotype × diagnosis (p > 0.05) effect on the delayed memory score after adjusting for covariates. The HHEX rs1111875 polymorphism was significantly associated with the delayed memory score in FSP (p < 0.05), but not in healthy controls (p > 0.05) after adjusting for covariates. Our findings supported that the HHEX rs1111875 polymorphism did not contribute to the susceptibility to FSP. However, this polymorphism might influence the delayed memory in FSP. Moreover, FSP had poorer cognitive function than healthy controls except for the visuospatial/constructional domain.

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.

Cognitive trajectories following onset of psychosis: a meta-analysis

BACKGROUND

Cognitive impairment is a core feature of schizophrenia, associated with poor functional outcomes. The course of cognitive function in the years following illness onset has remained a subject of debate, with a previous analysis finding no worsening, providing support for the neurodevelopmental model of schizophrenia. Since then, many more studies have reported on longitudinal cognitive performance in early psychosis, with some indicating deterioration, which does not align with this view.

AIMS

This study aims to quantitatively review the literature on the longitudinal trajectory of cognitive deficits in the years following psychosis onset, in comparison with healthy controls. It is the first to also synthesise longitudinal data on social cognition.

METHOD

Electronic databases ('PubMed', 'PsycInfo' and 'Scopus') were searched (to end September 2021). Meta-analyses of 25 longitudinal studies of cognition in early psychosis were conducted (1480 patients, 789 health controls). Unlike previous analyses, randomised controlled trials and those with multiple cognitive testing periods within the first year were excluded to minimise bias (PROSPERO, ID: CRD42021241525).

RESULTS

Small improvements were observed for global cognition (g = 0.25, 95% CI 0.17-0.33) and individual cognitive domains, but these were comparable with healthy controls and likely an artefact of practice effects.

CONCLUSIONS

There is no evidence of continued cognitive decline or improvement in the early years following psychosis onset, with a need for more studies over longer follow-up periods. Practice effects highlight the importance of including control samples in longitudinal and intervention studies. Further data are needed to evaluate the course of social cognition subdomains.

The association between cytokines and psychomotor speed in a spectrum of psychotic disorders: A longitudinal study

Background

In schizophrenia, impaired psychomotor speed is a common symptom predicting worse functional outcome. Inflammation causes changes in white matter integrity, which may lead to reduced psychomotor speed. Therefore, we wanted to investigate if peripheral inflammation assessed with cytokines affected performance on psychomotor speed in patients with a spectrum of psychotic disorders.

Methods

The current study is a prospective cohort study, including participants from a pragmatic, randomised controlled trial comparing three atypical antipsychotics in patients with a spectrum of psychotic disorders. For the purposes of this sub-study, we analysed drug treatment groups collectively. Psychomotor speed was assessed at baseline, and at weeks 6, 12, 26 and 52 of follow-up, using the neuropsychological tests trail making test (TMT) A and B, and symbol coding. Serum concentration of the following cytokines were measured: interleukin (IL)-β, IL-2, IL-4, IL-6, IL-10, IL12 p70, IL-17a, interferon (IFN)-γ and tumor necrosis factor (TNF)-α. Blood samples were collected at baseline and after 1, 3, 6, 12, 26, 39 and 52 weeks. We analysed the effect of cytokines levels on psychomotor speed over time in linear mixed effects models.

Results

In our linear mixed effects models controlling for possible confounders, IFN-γ had a significant negative effect on TMT-A and symbol coding performance. None of the other tests for psychomotor speed were significantly associated with cytokines. Overall psychomotor speed performance increased significantly across the study period while cytokine levels remained stable.

Conclusion

Our study indicates a negative association between IFN-γ and psychomotor speed, which might be of importance when understanding the mechanisms behind psychomotor deviations in psychotic disorders.

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The cytokine interferon (IFN) – γ is related to psychomotor speed in patients with psychotic disorders.

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For majority of cytokines, we found no significant association with psychomotor speed.

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Cytokines remained stable during the study period of 52 weeks.

How Do Early Psychosis Services Define and Operationalize the Duration of Untreated Psychosis?

Reducing the duration of untreated psychosis (DUP) is a key aim of early psychosis (EP) care. However, substantial variability in how the start and end points of DUP are defined impact its utility in clinical decision-making, and as an outcome measure. In this study, qualitative interviews were conducted with providers to assess how EP services and providers define, operationalize, and measure DUP. Twenty-five providers across 14 clinics were interviewed. Participants emphasized symptom frequency, conviction, distress caused, and impact when determining psychosis onset. DUP endpoint was typically identified as the first assessment in an episode of care that included an accurate diagnosis, leading to specialty EP treatment. Participants proposed a more structured operationalization of DUP, relative to those historically adopted in the literature. Integrating front-line provider perspectives could improve the accuracy of DUP measurement and address the heterogeneity in how the construct is operationalized across research and practice.

What is the optimal neuropsychological test battery for schizophrenia in China?

BACKGROUND

The MATRICS consensus cognitive battery (MCCB) has been widely used to evaluate cognitive deficits in schizophrenia (SCZ), however, no study has formally examined the validity of the MCCB in Chinese SCZ. This study compared Chinese SCZ patients with healthy Chinese controls on the MCCB and some additional neurocognitive tests to determine if the Chinese MCCB is an optimal battery to assess the cognitive deficits in Chinese SCZ patients.

METHOD

The study enrolled and examined 230 patients met DSM-IV criteria for SCZ and 656 healthy controls matched for gender, age and education. Besides the MCCB, we also included some additional neurocognitive tests that have been widely used in patients with schizophrenia. We selected MCCB and non-MCCB tests with large effect size, to assemble a new "optimal battery" and compared its performance with that of the standard MCCB.

RESULTS

Comparing the putative "optimal" battery with the original MCCB, more patients with SCZ were identified as cognitively impaired according to the criteria of GDS ≥ 0.50 for the optimal battery (166 vs 135, or 72.2% vs 58.7%). The rate of cognitive impairment according to MCCB GDS in patients with SCZ who were currently working, ever worked and never worked are 45.5%, 61.6% and 70.8% (p = 0.051), whereas the optimal battery GDS showed 56.4%, 74.8%, 91.7% (p = 0.003), respectively.

CONCLUSIONS

Our study needs validation with independent samples but suggests that the current "optimal" cognitive battery could be more sensitive than the widely used MCCB in detecting SCZ related cognitive impairment in China.

Association between decreased serum TBIL concentration and immediate memory impairment in schizophrenia patients

Cognitive impairment is a core feature of schizophrenia (SCH). In addition to the toxic effect of Bilirubin (BIL), it has antioxidant properties that were associated with the psychopathology and cognitive impairment of psychiatric disorders. The aim of this study was to examine the correlation of serum total BIL (TBIL) concentration with cognitive impairment in SCH patients. We recruited 34 SCH patients and 119 healthy controls (HCs) in this case-control design. Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Serum TBIL concentration was measured using the immunoturbidimetric method. Serum TBIL concentration was significantly decreased in SCH patients compared to HCs after adjusting for age, gender, and education. Serum TBIL concentration in SCH patients was also positively correlated with the RBANS immediate memory score. Further stepwise multiple regression analysis confirmed the positive association between serum TBIL concentration and immediate memory score in SCH patients. Our findings supported that the decline in serum TBIL concentration was associated with the immediate memory impairment and psychopathology of SCH.

Neurocognitive performance predicts treatment outcome with cognitive behavioral therapy for major depressive disorder

The current study examined the contribution of baseline neuropsychological functioning to the prediction of antidepressant outcome with cognitive behavioral therapy (CBT) for Major Depressive Disorder (MDD). We hypothesized that depressed participants who were more neurocognitively intact and had less rigid, negative thinking would respond better to CBT. Thirty-one MDD patients completed a comprehensive neuropsychological battery before initiation of CBT. A subgroup also completed a probabilistic reversal learning task. Depression severity was assessed with the Beck Depression Inventory (BDI); rigid, negative thinking was assessed with the Dysfunctional Attitudes Scale (DAS) and the Automatic Thoughts Questionnaire (ATQ) throughout treatment. Remitters were compared to non-remitters. Paradoxically, eventual remitters performed generally worse across the neuropsychological battery considered as a whole. Univariate testing showed a significant difference on only a single measure, the Continuous Performance Test d', when corrected for multiple comparisons. Baseline rigid, negative thinking did not predict treatment outcome. Results suggest that the structure of CBT may particularly benefit individuals with mild depression-related neurocognitive difficulties during a depressive episode. Further research is needed to examine these patient characteristics and their potential contribution to the mechanisms of CBT efficacy.

A longitudinal study on the relationship between duration of untreated psychosis and executive function in early-onset first-episode psychosis

BACKGROUND

The relationship between duration of untreated psychosis (DUP) and executive function (EF) in patients with first-episode psychosis (FEP) is controversial. We aim to assess the influence of DUP on changes in EF over a 2-year period in subjects with early-onset FEP (first psychotic symptom before age 18) and less than 6 months of positive symptoms.

METHODS

A total of 66 subjects were included in the study (19 females [28.8%], mean age 16.2 ± 1.6 years). The influence of DUP on changes in EF over the 2-year follow-up (expressed as a composite score of 5 cognitive abilities: attention, working memory, cognitive flexibility, response inhibition, and problem solving) was estimated using a multivariate linear regression model after removing the effect of intelligence quotient and controlling for age, gender, diagnosis, premorbid adjustment, severity of positive and negative symptoms at baseline, global functioning at baseline, and mean daily antipsychotic dosage during follow-up.

RESULTS

Mean DUP was 65.0 ± 6.9 days (95% confidence interval [CI], 51.2, 78.8). Median DUP was 47.5 days (range 2-180 days). Negative symptoms at baseline was the only variable significantly associated with EF at baseline (10.9% of explained variance [e.v. 10.9%], p=0.007). Only shorter DUP (e.v. 8.7%, p=0.013) and greater severity of baseline negative symptoms (e.v. 10.0%, p=0.008) were significantly associated with greater improvement in EF.

CONCLUSIONS

In early-onset FEP, shorter DUP was associated with greater improvement in EF over a 2-year follow-up period.

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.

Does active psychosis cause neurobiological pathology? A critical review of the neurotoxicity hypothesis

BACKGROUND

Since the neurotoxicity hypothesis was launched in 1991, it has generated a great deal of interest and given rise to several studies investigating the validity of the hypothesis that being psychotic has a toxic effect on the brain. The toxicity argument is used to justify early treatment. This review attempts to assess the studies that have addressed the question: Does an active psychosis, indexed by the duration of untreated psychosis (DUP), cause neurobiological pathology?

METHOD

The validity of the hypothesis has been studied primarily by correlation analyses that assess whether there are significant correlations between DUP and changes in neurocognitive functioning or brain structure. In this review, relevant reports were identified by a literature survey.

RESULTS

Of the 35 studies (33 papers) evaluated, six neurocognitive studies supported the hypothesis and 16 did not. Eight morphology studies supported the hypothesis and five did not. In general, the studies that did not support the neurotoxicity hypothesis were larger in size and had more adequate designs (longitudinal) than those that supported the hypothesis.

CONCLUSIONS

Overall, there is limited empirical evidence for the neurotoxicity hypothesis in the studies reviewed. However, it is possible that there is a threshold value for a toxic effect of psychosis, rather than a linear relationship between DUP and a neurotoxic effect, and that several of the studies evaluated did not have a long enough DUP to detect a toxic effect of active psychosis.

Distinct effects of duration of untreated psychosis on brain cortical activities in different treatment phases of schizophrenia: a multi-channel near-infrared spectroscopy study

BACKGROUND

Duration of untreated psychosis (DUP) has been shown to be associated with both poor short-term and long-term outcomes in schizophrenia. Even so, few studies have used functional neuroimaging to investigate DUP in schizophrenia. In the present study, we used near-infrared spectroscopy (NIRS) to investigate the influence of DUP on brain functions during a verbal fluency test (VFT) in patients with schizophrenia.

METHODS

A total of 62 patients with schizophrenia were included. They were categorized into either short treatment (≤6months, n=33) or long treatment (>6months, n=29) groups based on their duration of treatment. Hemodynamic changes over the frontotemporal regions during a VFT were measured using multi-channel NIRS. We examined the associations between DUP and hemodynamic changes in each group to explore if there were different effects of DUP on brain cortical activity at different treatment durations.

RESULTS

In the long treatment group, we found significant associations between a longer DUP and decreased cortical activity approximately at the left inferior frontal gyrus, left middle frontal gyrus, left postcentral gyrus, right precentral gyrus, bilateral superior temporal gyrus, and bilateral middle temporal gyrus, whereas no associations between DUP and brain cortical activity were observed in the short treatment group.

CONCLUSIONS

Our results indicated that longer DUP may be associated with decreased level of cortical activities over the frontotemporal regions in the long-term. Early detection and intervention of psychosis that shortens DUP might help to improve the long-term outcomes in patients with schizophrenia.

Neuropsychologic functioning and structural MRI of the brain in patients with schizophrenia

The first episode of schizophrenia represents a transition from a premorbid to a morbid state. Studying the first episode of schizophrenia is useful since it is devoid of the confounds of chronicity and long-term medication. It is also likely to direct us to the core deficits of the illness. Studies on first-episode schizophrenia suggest a generalized neuropsychologic impairment, but that memory, attention and executive function are more severely impaired. Support for a neurodevelopmental model of neuropsychologic impairment in schizophrenia is derived from the findings that much of the neuropsychologic impairment is present by illness onset, that neuropsychologic impairment remains stable over time and that there is a weak relation between duration of untreated psychosis and neuropsychologic impairment. However, neuropsychologic impairment is moderated by neuroleptic treatment, with some evidence that atypical antipsychotics may have some beneficial effects over conventional antipsychotics. The causal mechanisms of brain abnormality in the temporal and frontal lobes appear to be different to that of neuropsychologic impairment in schizophrenia. The observation that there is a brain volume decrement over time and that the rate of change is higher during the first 5 years would be consistent with a neurodegenerative model of schizophrenia. At the same time, the basal ganglia are vulnerable to volumetric increase secondary to neuroleptic medication. Understanding the roles of the neurodevelopmental and neurodegenerative models of schizophrenia is important in deciding intervention strategies.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Impacts of duration of untreated psychosis on cognition and negative symptoms in first-episode schizophrenia: a 3-year prospective follow-up study

BACKGROUND

Cognitive impairment is a core feature of schizophrenia. Its relationship with duration of untreated psychosis (DUP), a potentially malleable prognostic factor, has been less studied, with inconsistent findings being observed in the literature. Previous research investigating such a relationship was mostly cross-sectional and none of those prospective studies had a follow-up duration beyond 2 years. Method A total of 93 Hong Kong Chinese aged 18 to 55 years presenting with first-episode schizophrenia-spectrum disorder were studied. DUP and pre-morbid adjustment were measured using a structured interview incorporating multiple sources of information. Psychopathological evaluation was administered at intake, after clinical stabilization of the first psychotic episode, and at 12, 24 and 36 months. Cognitive functions were measured at clinical stabilization, and at 12, 24 and 36 months.

RESULTS

DUP exerted differential effects on various cognitive domains, with memory deficits being the most related to DUP even when potential confounders including pre-morbid adjustment and sex were adjusted. Prolonged DUP was associated with more severe impairment in visual memory at clinical stabilization and verbal memory at 24 and 36 months. Further, patients with a long DUP were found to have worse outcomes on negative symptoms at 36 months. The effects of DUP on verbal memory remained significant even when negative symptoms were taken into consideration.

CONCLUSIONS

Our findings provided further supportive evidence that delayed treatment to first-episode psychosis is associated with poorer cognitive and clinical outcomes. In addition, DUP may specifically affect memory function and its adverse impact on verbal memory may only become evident at a later stage of the recovery process.

Association between DBH 19 bp insertion/deletion polymorphism and cognition in first-episode schizophrenic patients

Many genes associated with dopamine (DA) and norepinephrine (NE) systems influence cognitive deficits of schizophrenia patients, but one key enzyme is dopamine beta-hydroxylase (DBH), which converts DA to NE and whose activity and levels are under strong genetic control. This study examines the association of the 19 bp insertion/deletion (Ins/Del) polymorphism in the 5' flank of the DBH gene with cognitive deficits in first-episode schizophrenic patients (FEP). We assessed the cognitive function in 195 FEP and 304 healthy controls using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The 19 bp Ins/Del polymorphism of DBH gene was genotyped. Our results showed that the allelic and genotypic frequencies of the 19 bp Ins/Del polymorphism significantly differed between FEP and healthy controls (both p < 0.05). Cognitive test scores were significantly lower in FEP than healthy controls on all scales (all p < 0.001) except for the visuospatial/constructional index (p > 0.05). Immediate memory abilities significantly differed by genotype (p<0.05) but not genotype×diagnosis. Immediate memory score was lower in FEP with DBH5'-Del/Del genotype (61.3 ± 17.2) than those with DBH5'-Ins/Ins genotype (68.6 ± 16.2; p < 0.05). The 19 bp Del allele was associated with poorer immediate memory performance than the Ins allele in FEP (p < 0.05). However, healthy controls did not show any differences in cognitive function indices between the Ins and Del for either the allele or genotype of the 19 bp Ins/Del polymorphism. Our findings suggest that the DBH5'-Ins/Del polymorphism may play a role in susceptibility to FEP. The DBH5'-Ins/Del polymorphism may also influence immediate memory in FEP. Moreover, FEP had poorer cognitive function than healthy controls in all examined cognitive domains except for the visuospatial/constructional index.

Executive functioning in schizophrenia spectrum disorder patients and their unaffected siblings: a ten-year follow-up study

Executive dysfunction represents a core deficit that is associated with schizophrenia spectrum disorders (SSDs). However, the longitudinal course of executive deficits in SSDs is still controversial. The aim of this study was to examine the executive performance of 34 SSD patients in relation to 34 of their unaffected siblings over a period of 10 years. Both groups completed psychopathological and executive assessments. Thirteen healthy controls were assessed using the same instruments. At baseline, the SSD patients differed significantly from siblings and controls in their performance on the Trail Making Test-B (TMT-B) and the number of categories in which they succeeded in the Wisconsin Card Sorting Test (WCST). They also differed significantly from the controls in the total number of errors in the WCST. The siblings did not differ in executive functioning from the controls over the follow-up. Longitudinally, the patients demonstrated significant improvement only for the TMT-B. However, only 14.71% of the patients showed reliable and clinically significant improvements for the TMT-B, and 8.82% made more errors on the WCST at the follow-up evaluation. Less than 3% of the patients showed either improved or worse results on the remaining measures of the WCST. A stabilisation pattern for the WCST was observed in the three groups. The patients performed worse than their siblings and controls on both executive tests. Some patients exhibited significant improvements in the TMT-B over time, but this improvement was reliable and clinically significant for less than 15% of the sample. Thus, we conclude that the patients exhibited stable impairments over time in the executive functions assessed.

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.

IQ trajectory, cognitive reserve, and clinical outcome following a first episode of psychosis: a 3-year longitudinal study

Comparison of current and estimated premorbid IQ in schizophrenia suggests that there are subgroups with low IQ, deteriorated IQ (DIQ), or preserved IQ and that this is established by psychosis onset. There are no controlled studies examining the trajectory of these IQ subgroups longitudinally or their relationship with clinical and social outcomes. Of 129 individuals with first-episode schizophrenia or schizoaffective disorder, 25% showed stable low IQ, 31% showed stable IQ in the average/high range, and 44% demonstrated intellectual deterioration by 10 points or more. Patients in the low and deteriorated groups were equally impaired on tests of memory and executive function compared with the preserved average/high-IQ group and controls and showed more negative and disorganization symptoms than the preserved average/high-IQ group. Sixty patients and 27 controls were assessed again 1 and 3 years later. There was no evidence that those with IQ deterioration at baseline continued on a declining cognitive trajectory or that those with preserved average/high IQ experienced subsequent IQ decline. The low IQ group showed no change in IQ, whereas both the DIQ and the preserved IQ groups improved. However, the rate of improvement of these 2 subgroups was no greater than that of the healthy controls, suggesting that this reflected practice effects. Both the low and the deteriorated groups had longer index admissions, more core negative symptoms, and worse occupational outcomes at 3 years. These data suggest that following psychosis onset, IQ is stable and that it is IQ at psychosis onset rather than premorbid IQ predicts a more severe illness.

Relational memory in first episode psychosis: implications for progressive hippocampal dysfunction after illness onset

OBJECTIVE

Verbal episodic memory deficits are prominent in schizophrenia and have also been found in first episode psychosis (FEP) and individuals at clinical risk of the disorder. The central role of the hippocampus in verbal memory processing and the consistent findings of hippocampal volume reductions in chronic patients have prompted the suggestion that impaired verbal memory performance may be a biomarker of schizophrenia. However, it is currently unclear as to when, during the early phase of psychosis, verbal memory performance becomes significantly impaired. The current study investigated verbal relational memory in FEP using a novel verbal paired associate task, and tested whether performance was dependent on phase of illness within FEP, where patients with a diagnosis of schizophrenia were considered to be in a more advanced stage than those with schizophreniform disorder.

METHOD

Forty-seven currently psychotic FEP patients and 36 healthy non-psychiatric controls, aged 15-25 years old, completed a test comprising four trials of learning and cued recall of word pairs (denoted AB pairs), an interference phase comprising two trials with new second words (AC pairs), and finally cued recall for the original AB pairings.

RESULTS

FEP patients performed similarly to controls on the relational memory task. There was no difference in performance between FEP patients who had a diagnosis of schizophrenia and those with a diagnosis of schizophreniform disorder.

CONCLUSIONS

Verbal relational memory appears to be intact in FEP. This finding, along with chronic patient literature, suggests that decline in hippocampal and medial temporal lobe functioning occurs during later illness stages. Further research is needed to aid in the development of intervention strategies that may prevent decline in such cognitive domains at this crucial early stage of the illness.

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.

Sustained attention and planning deficits but intact attentional set-shifting in neuroleptic-naïve first-episode schizophrenia patients

INTRODUCTION

The nature of deficits in tests of sustained attention, planning and attentional set-shifting has not been investigated in neuroleptic-naïve first-episode (FE) schizophrenia patients. Based on previous literature of chronic and medicated FE schizophrenia patients, we predicted that the neuroleptic-naïve patients would show deficits in these cognitive processes.

METHODS

Twenty-nine neuroleptic-naïve FE schizophrenia patients and 33 healthy controls - matched by age, gender, and nicotine consumption - performed 3 tests from the Cambridge Automated Neuropsychological Test Battery (CANTAB) thought to measure these cognitive processes: the Rapid Visual Information Processing task (RVIP, sustained attention), the Stockings of Cambridge task (SOC, planning), and the Intradimensional/Extradimensional set-shifting task (IDED, attention shifting).

RESULTS

The patients were significantly impaired in the sensitivity index (A') of the RVIP, and in the number of problems solved with minimum moves on the SOC. Nevertheless, the groups did not differ regarding the number of participants who failed at the crucial extradimensional shift stage of the IDED.

CONCLUSION

Sustained attention and planning abilities are already impaired in neuroleptic-naïve FE schizophrenia patients, whereas set-shifting abilities as measured with the IDED task seem to be intact at illness onset. Since chronic schizophrenia patients have been shown to have impaired IDED performance, we tentatively propose that IDED performance deteriorates over time with illness chronicity and/or medication.

Longitudinal studies of cognition in schizophrenia: meta-analysis

BACKGROUND

A wide range of cognitive deficits have been demonstrated in schizophrenia, but their longitudinal course remains unclear.

AIMS

To bring together all the available information from longitudinal studies of cognitive performance in people with schizophrenia.

METHOD

We carried out a meta-analysis of 53 studies. Unlike previous reviewers, we included all studies (regardless of the type of medication), analysed each variable separately and compared results with data from controls.

RESULTS

Participants with schizophrenia showed a significant improvement in most cognitive tasks. The available data for controls showed, with one exception (the Stroop test), a similar or greater improvement. Performance in semantic verbal fluency remained stable in both individuals with schizophrenia and controls.

CONCLUSIONS

Participants with schizophrenia displayed improvement in most cognitive tasks, but practice was more likely than cognitive remediation to account for most of the improvements observed. Semantic verbal fluency may be the best candidate cognitive endophenotype.

The course of neurocognitive functioning in first-episode psychosis and its relation to premorbid adjustment, duration of untreated psychosis, and relapse

The aim was to determine the post-onset longitudinal course of cognitive functioning in first-episode psychoses and to examine how premorbid adjustment, duration of untreated psychosis (DUP), and clinical variables such as relapse are associated with that course. Consecutive patients with a DSM-IV diagnosis of non-organic psychosis coming to their first treatment in the health care areas under study were included. Ultimately, 207 patients were assessed neuropsychologically at baseline, 138 were reassessed one year later, and 111 two years later. Five dimensions were identified through principal component analysis of eight neuropsychological (NP) test results: Working Memory (WM), Executive Function (EF), Verbal Learning (VL), Impulsivity (Im), and Motor Speed (MS). No major changes were found in the level of neurocognitive functioning from baseline to the 1-year and 2-year follow-ups. Patients with good initial levels of premorbid academic functioning had consistently better scores on WM at all three time points. No association was found between DUP and the longitudinal course of neurocognitive function. Significant associations occurred between better WM and VL at 1 and 2 years and fewer relapses during the first year, but not the second. Most NP deficits are in place by onset of psychosis and are stable over two years. Milder WM deficits are associated with higher premorbid academic functioning. More severe deficits in WM and VL are associated with more relapses during the first year. It is unclear whether NP deficits cause relapse, relapse causes NP deficits, or both are manifestations of a third deteriorative process.

Stability of estimated IQ across mood state in patients with bipolar disorder

OBJECTIVES

The goal of this study was to assess the impact of mania symptoms on the stability of the American version of the National Adult Reading Test (ANART), a measure that provides a putative estimate of premorbid intellectual functioning.

METHODS

The ANART was administered to a sample of 10 inpatients with bipolar disorder who were experiencing an acute episode of mania. During a subsequent follow-up visit during which these individuals exhibited at most minimal mood symptoms, the ANART was re-administered.

RESULTS

ANART estimated intelligence quotient (IQ) scores during mania and affective stability were assessed in the 10 patients using a paired sample t-test. Within-subject performance across the two mood states did not significantly differ [t(9) = -1.24, p = 0.25]. Additionally, the greatest individual difference across mood states was only 3.68 points, and the average estimated IQ difference across mood states was 1.66.

CONCLUSIONS

While the results are preliminary and based on a small sample, the highly consistent scores achieved across mood states in this study suggest that the ANART is a reliable indicator of premorbid IQ.

GENDER DIFFERENCES IN PERFORMANCE ON THE STROOP TEST

This study assessed differences in gender performance among Kuwaiti male and women on the Stroop Test (Stroop, 1935). Participants were 504 university students, 122 men and 382 women (age M= 21:0, SD= 2.7 yrs). Prior studies have shown that females by and large display differential performance (shorter latencies) from males on the word card, color card, and color word card of the Stroop Test. Results indicate that the Kuwaiti women read faster on the color card than did the males, and especially were faster with intercepting three cards of tests (interaction effect). Gender differences were observed in the color card and color-word card tests but not significantly for the word card test. The results do substantiate the gender difference in Stroop color and interference.

The course of cognitive functioning in first episode psychosis: changes over time and impact on outcome

This three year longitudinal study examined the cognitive performance of 247 individuals who recently presented with a first episode of psychosis. Using a comprehensive battery of cognitive tests, we assessed cognition at baseline, 1 year and 2-year follow-ups. Assessments also included positive and negative symptoms, depression, social outcome and substance use. There were several significant improvements in cognition over the two-year period which were usually matched by improvements in a matched non-psychiatric control group. Regression analyses demonstrated that after controlling for symptoms cognitive impairment accounted for 4-6% of the variance in social functioning. Our results suggest that impaired cognition exists in the very early stages of a psychotic illness and that there is no decline over time. Secondly, our results suggest that, although related, poor social functioning deficits may be independent of cognitive impairment. Finally there are implications for improved methodology in the assessment of both cognitive and social functioning.

Functional imaging evidence of the relationship between recurrent psychotic episodes and neurodegenerative course in schizophrenia

It remains controversial as to what determines the neurodegenerative course in schizophrenia. This study administered a modified version of the Stroop task and investigated the relationship between functional magnetic resonance imaging (fMRI) signal changes in dysfunctioned task-related regions and clinical course variables. Functional MRI data during task performance were acquired from 10 right-handed schizophrenic patients (mean+/-SD age=29.2+/-10.3 years, range of illness duration=0.8-14 years, number of episodes=1-5) and 10 healthy controls (mean+/-SD age=30.3+/-6.4). Imaging data were investigated on a voxel-by-voxel basis for single group analysis and for between-group analysis according to the random effect model using Statistical Parametric Mapping (SPM 99b). Correlation analysis with age as a covariate identified those brain regions whose fMRI signal changes were significantly related to clinical course variables in schizophrenia. The number of psychotic episodes was negatively correlated with the fMRI signal change in the right inferior frontal and the right frontal precentral gyri among the activated regions during the Stroop task in schizophrenia, whereas the length of illness was not so correlated. The number of psychotic episodes was also negatively correlated with the fMRI signal change in the left paracingulate in which functional activity was diminished in the patients relative to the controls. Our results indicate that recurrent psychotic episodes are related to the neurodegenerative course in some dysfunctional brain regions in schizophrenia.

A Canadian programme for early intervention in non-affective psychotic disorders

OBJECTIVES

To provide a brief overview of the development of clinical services and research for early intervention in psychotic disorders in Canada; to describe components of a comprehensive clinical/research programme for nonaffective psychotic disorders; and to present a summary of results of clinical and social outcomes achieved.

METHOD

This is a descriptive paper providing some details of how clinical services are being developed in Canada and concentrating on one particular early intervention programme, Prevention and Early intervention Programme for Psychoses (PEPP) London, Ontario, which is using a historical control design to evaluate the impact of an assertive approach to community case detection. Components of a phase-specific treatment programme and early case detection are described followed by results based on clinical and psychosocial data collected according to a defined protocol.

RESULTS

One year outcome for patients treated in PEPP shows use of low dose, pre-dominantly novel antipsychotics and high (81.5%) retention and remission (75%) rates. Highly significant improvements were also reported for self-rated quality of life and cognition. Duration of untreated psychosis (DUP) and premorbid adjustment were associated with improvement in positive and negative symptoms, respectively. Systemic changes to improve access to the service resulted in substantial increases in number of cases treated and a> 50% decline in DUP.

CONCLUSIONS

Phase-specific treatment approach and case identification strategies to reduce delay in treatment are likely to substantially improve outcome in nonaffective psychotic disorders compared with what has been reported with traditional approaches.