Neurocognitive impairment in schizophrenia and how it affects treatment options

Driving fitness in clinically stable outpatients with chronic schizophrenia

INTRODUCTION

Driving motorized vehicles is an integral part of individual mobility and a key parameter for employment and social integration. This naturalistic, cross-sectional study investigated the associations between driving fitness, residual symptomatology, olanzapine equivalent, and extrapyramidal symptoms (EPS) in long term stable outpatients with schizophrenia.

METHODS

Beside sociodemographic data, and driving habits, residual symptoms, and EPS were assessed using the Positive and Negative Syndrome Scale (PANSS), and the Modified Simpson Angus Scale (MSAS). PANSS symptoms were analyzed using the Wallwork/Fortgang five-factor model. MSAS cut-off scores ≥3 were defined as positive for EPS. Driving skills were assessed using the Vienna Test System and an expert evaluation.

RESULTS

50 patients were included into the study. Mean PANSS total scores indicated mild residual symptomatology and EPS were not present in 48% of study participants. 44% passed the driving fitness assessment and were considered as competent to drive, 20% were judged to be partially competent and 36% to be incompetent to drive. With the exception of disorganization (r = -0·287, p = 0·048) residual symptoms of schizophrenia did not correlate with driving fitness. However, moderate negative correlations were detected between driving fitness and the severity of EPS (r = -0·554, p = 0·000), age (r = -0·413, p = 0·003) as well as olanzapine equivalent doses (r = -0·432, p = 0·002). These results were not corrected for multiple comparison.

DISCUSSION

The present findings indicate that up to two thirds of clinically stable outpatients with chronic schizophrenia may be (partially) competent to drive. Both the presence of EPS as well as the dosage of antipsychotic medication seem to be of particular relevance in this regard.

COMT Val158Met polymorphism influences the susceptibility to framing in decision-making: OFC-amygdala functional connectivity as a mediator

Individuals tend to avoid risk in a gain frame, in which options are presented in a positive way, but seek risk in a loss frame, in which the same options are presented negatively. Previous studies suggest that emotional responses play a critical role in this "framing effect." Given that the Met allele of COMT Val158Met polymorphism (rs4680) is associated with the negativity bias during emotional processing, this study investigated whether this polymorphism is associated with individual susceptibility to framing and which brain areas mediate this gene-behavior association. Participants were genotyped, scanned in resting state, and completed a monetary gambling task with options (sure vs risky) presented as potential gains or losses. The Met allele carriers showed a greater framing effect than the Val/Val homozygotes as the former gambled more than the latter in the loss frame. Moreover, the gene-behavior association was mediated by resting-state functional connectivity (RSFC) between orbitofrontal cortex (OFC) and bilateral amygdala. Met allele carriers showed decreased RSFC, thereby demonstrating higher susceptibility to framing than Val allele carriers. These findings demonstrate the involvement of COMT Val158Met polymorphism in the framing effect in decision-making and suggest RSFC between OFC and amygdala as a neural mediator underlying this gene-behavior association. Hum Brain Mapp 37:1880-1892, 2016. © 2016 Wiley Periodicals, Inc.

Do patterns of mental healthcare predict treatment failure in young people with schizophrenia? Evidence from an Italian population-based cohort study

OBJECTIVE

Little is known about the practice of predicting community-based care effectiveness of patients affected by schizophrenic disorders. We assessed predictors of treatment failure in a large sample of young people affected by schizophrenia.

METHODS

A cohort of 556 patients aged 18-35 years who were originally diagnosed with schizophrenia during 2005-2009 in a Mental Health Service (MHS) of the Italian Lombardy Region was identified. Intensity of mental healthcare received during the first year after index visit (exposure) was measured by patients' regularity in MHS attendance and the length of time covered with antipsychotic drug therapy. Patients were followed from index visit until 2012 for identifying hospital admission for mental disorder (outcome). A proportional hazards model was fitted to estimate the HR and 95% CIs for the exposure-outcome association, after adjusting for several covariates. A set of sensitivity analyses were performed in order to account for sources of systematic uncertainty.

RESULTS

During follow-up, 144 cohort members experienced the outcome. Compared with patients on low coverage with antipsychotic drugs (≤ 4 months), those on intermediate (5-8 months) and high (≥ 9 months) coverage, had HRs (95% CI) of 0.94 (0.64 to 1.40) and 0.69 (0.48 to 0.98), respectively. There was no evidence that regular attendance at the MHS affected the outcome.

CONCLUSIONS

Patients in the early phase of schizophrenia and their families should be cautioned about the possible consequences of poor antipsychotic adherence. Physicians and decision makers should increase their contribution towards improving mental healthcare.

Add-on clinical effects of selective antagonist of 5HT6 receptors AVN-211 (CD-008-0173) in patients with schizophrenia stabilized on antipsychotic treatment: pilot study

The serotoninergic system as a target for add-on treatment seems to be a promising approach in patients with schizophrenia.

OBJECTIVE

To clarify if selective 5HT-6 antagonist AVN-211 (CD-008-0173) adds clinical and cognitive effects to stable antipsychotic treatment.

METHODS

A randomized, double-blind, placebo-controlled, add-on, 4r-week trial in 47 schizophrenia patients (21 patients receiving study drug and 26 receiving placebo) who were stabilized on antipsychotic medication was performed. Seventeen patients from the study drug group and 25 patients from the placebo group completed the trial. Treatment effects were measured using clinical rating scales and attention tests.

RESULTS

With no differences at baseline, there was a significant difference between the groups in Positive and Negative Syndrome Scale (PANSS) positive subscale score (p = 0.058) in favor of patients in the treatment group at the endpoint. The PANSS positive subscore (p = 0.0068) and Clinical Global Impression-Severity (CGI-S) (p = 0.048) score significantly changed only in the treatment group. Only in the placebo group were significant changes in Calgary Depression Rating Scale (CDRS) total score registered. The indices of attention tests at endpoint did not show differences between the groups, with the exception of the scope of change in the results of the subtest VIII of the Wechsler Adult Intelligence Scale (WAIS), which showed difference between the groups (p = 0.02) and was significantly larger in the treatment group. Only inside the study drug group, significant changes in selectivity and continuous attention were observed regarding total correct responses (p = 0.0038) and reaction time (p = 0.058) in the Continuous Attention Task (CAT) test.

CONCLUSION

Selective 5HT6 antagonist AVN-211 (CD-008-0173) added antipsychotic and some procognitive (attention) effects to antipsychotic medication.

Increased serum dehydroepiandrosterone sulfate in the first episode but not in subsequent episodes in male patients with schizophrenia

BACKGROUND

Many studies have investigated the relationship between blood levels of dehydroepiandrosterone (DHEA) and its sulfate ester (DHEA-S), cortisol, progesterone, and testosterone and the onset, prognosis, symptom severity, and treatment response of schizophrenia. In the present study, we assessed potential differences in blood levels of neurosteroids between drug-naïve first-episode patients with schizophrenia (FES), and drug-free patients with schizophrenia who were not in the first episode but were in a phase of acute exacerbation (DFP).

MATERIALS AND METHODS

The present study included 32 male FES, 28 male DFP, and 24 male healthy controls (HC). Groups were compared in terms of blood levels of adrenocorticotropic hormone (ACTH), cortisol, testosterone, progesterone, and DHEA-S.

RESULTS

Blood levels of ACTH, cortisol, testosterone, and progesterone were similar among the groups. The mean value of serum DHEA-S was significantly different among the groups (P<0.001). The value of serum DHEA-S was higher in the FES group than in the DFP and HC groups (both P<0.001). The mean values of serum DHEA-S in the HC and DFP groups were found to be similar (P=0.33).

CONCLUSION

We suggest that higher values of DHEA-S in the FES group compared with both the DFP and HC groups indicate that this neurosteroid response is unique to first-episode schizophrenia patients. Further studies are needed to investigate the difference in blood levels of neurosteroids in different groups in terms of age of diagnosis.

Current approaches to treatments for schizophrenia spectrum disorders, part I: an overview and medical treatments

During the last three decades, an increasing understanding of the etiology, psychopathology, and clinical manifestations of schizophrenia spectrum disorders, in addition to the introduction of second-generation antipsychotics, has optimized the potential for recovery from the illness. Continued development of various models of psychosocial intervention promotes the goal of schizophrenia treatment from one of symptom control and social adaptation to an optimal restoration of functioning and/or recovery. However, it is still questionable whether these new treatment approaches can address the patients' needs for treatment and services and contribute to better patient outcomes. This article provides an overview of different treatment approaches currently used in schizophrenia spectrum disorders to address complex health problems and a wide range of abnormalities and impairments resulting from the illness. There are different treatment strategies and targets for patients at different stages of the illness, ranging from prophylactic antipsychotics and cognitive-behavioral therapy in the premorbid stage to various psychosocial interventions in addition to antipsychotics for relapse prevention and rehabilitation in the later stages of the illness. The use of antipsychotics alone as the main treatment modality may be limited not only in being unable to tackle the frequently occurring negative symptoms and cognitive impairments but also in producing a wide variety of adverse effects to the body or organ functioning. Because of varied pharmacokinetics and treatment responsiveness across agents, the medication regimen should be determined on an individual basis to ensure an optimal effect in its long-term use. This review also highlights that the recent practice guidelines and standards have recommended that a combination of treatment modalities be adopted to meet the complex health needs of people with schizophrenia spectrum disorders. In view of the heterogeneity of the risk factors and the illness progression of individual patients, the use of multifaceted illness management programs consisting of different combinations of physical, psychological, and social interventions might be efficient and effective in improving recovery.

Executive control: balancing stability and flexibility via the duality of evolutionary neuroanatomical trends

The concept of executive functions has a rich history and remains current despite increased use of other terms, including working memory and cognitive control. Executive functions have sometimes been equated with functions subserved by the frontal cortex, but this adds little clarity, given that we so far lack a comprehensive theory of frontal function. Pending a more complete mechanistic understanding, clinically useful generalizations can help characterize both healthy cognition and multiple varieties of cognitive impairment. This article surveys several hierarchical and autoregulatory control theories, and suggests that the evolutionary cytoarchitectonic trends theory provides a valuable neuroanatomical framework to help organize research on frontal structure-function relations. The theory suggests that paleocortical/ventrolateral and archicortical/dorsomedial trends are associated with neural network flexibility and stability respectively, which comports well with multiple other conceptual distinctions that have been proposed to characterize ventral and dorsal frontal functions, including the “initiation/inhibition,” “what/where,” and “classification/expectation” hypotheses.

Inhibition of cerebral type 1 cannabinoid receptors is associated with impaired auditory mismatch negativity generation in the ketamine model of schizophrenia

RATIONALE

Preclinical and clinical research suggests that the endogenous cannabinoid system is involved in cognitive impairments related to schizophrenia. In particular, the deficient generation of mismatch negativity (MMN) indicating auditory sensory memory is a characteristic finding in schizophrenic patients. Experimental studies implicate deficient N-methyl-D: -aspartate (NMDA) receptor functioning in such abnormalities.

OBJECTIVES

The primary aim of this study was to investigate the effects of the cannabinoid CB(1) receptor antagonist rimonabant on MMN deficits in the NMDA receptor antagonist model of schizophrenia by using ketamine.

METHODS

Twenty-four healthy male subjects participated in a randomized, double-blind, placebo-controlled cross-over study with subanesthetic doses of intravenous ketamine. The MMNs to frequency and duration deviants were elicited within an auditory oddball paradigm and recorded by a 32-channel EEG. Psychopathology was assessed using the Psychotomimetic States Inventory.

RESULTS

Twenty subjects completed both experimental sessions. Ketamine infusion had no significant effect on MMN amplitudes in both deviance conditions. In contrast to placebo, co-administration of rimonabant produced significant deficits in MMN amplitudes to duration deviants at electrode position Fz.

CONCLUSIONS

The results point to the involvement of the endogenous cannabinoid system in auditory sensory memory as a cognitive key feature in schizophrenia. They particularly suggest that CB(1) receptor antagonism may impair cognitive performance by a disturbed interaction between endocannabinergic activity and glutamatergic neurotransmission implied in schizophrenia.

Pharmacotherapy for treatment-resistant schizophrenia

Schizophrenia is a disabling mental illness with a lifetime prevalence of 0.7% worldwide and significant, often devastating, consequences on social and occupational functioning. A range of antipsychotic medications are available; however, suboptimal therapeutic response in terms of psychotic symptoms is common and affects up to one-third of people with schizophrenia. Negative symptoms are generally less amenable to treatment. Because of the consequences of inadequate symptom control, effective treatment strategies are required for people with treatment-resistant schizophrenia. Clozapine has been shown to be more effective than other antipsychotics in treatment-resistant populations in several studies; however, the occurrence of adverse effects, some of which are potentially life-threatening, are important limitations. In addition to those who are intolerant to clozapine, only 30% to 50% experience clinically significant symptom improvement. This review describes the recent evidence for treatment strategies for people not responding to nonclozapine antipsychotic agents and people not responding or only partially responding to clozapine.

Schizophrenia, "just the facts" 5. Treatment and prevention. Past, present, and future

The introduction of second-generation antipsychotics and cognitive therapies for schizophrenia over the past two decades generated considerable optimism about possibilities for recovery. To what extent have these developments resulted in better outcomes for affected individuals? What is the current state of our science and how might we address the many unmet needs in the prevention and treatment of schizophrenia? We trace the evolution of various treatments for schizophrenia and summarize current knowledge about available pharmacological and psychosocial treatments. We consider the widely prevalent efficacy-effectiveness gap in the application of available treatments and note the significant variability in individual treatment response and outcome. We outline an individualized treatment approach which emphasizes careful monitoring and collaborative decision-making in the context of ongoing benefit-risk assessment. We note that the evolution of both pharmacological and psychosocial treatments thus far has been based principally on serendipity and intuition. In view of our improved understanding of the etiology and pathophysiology of schizophrenia, there is an opportunity to develop prevention strategies and treatments based on this enhanced knowledge. In this context, we discuss potential psychopathological treatment targets and enumerate current pharmacological and psychosocial development efforts directed at them. Considering the stages of schizophrenic illness, we review approaches to prevent progression from the pre-symptomatic high-risk to the prodrome to the initial psychotic phase to chronicity. In view of the heterogeneity of risk factors, we summarize approaches towards targeted prevention. We evaluate the potential contribution of pharmacogenomics and other biological markers in optimizing individual treatment and outcome in the future.

Interpretation of the RBANS in inpatient psychiatry: clinical normative data and prevalence of low scores for patients with schizophrenia

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS; Randolph, 1998) is a screening battery designed to measure attention and processing speed, expressive language, visual-spatial and constructional abilities, and immediate and delayed memory. Clinical normative data for a large sample of inpatients and outpatients with schizophrenia spectrum disorders is available (Wilk, Gold, Humber, Dickerson, Fenton, & Buchanan, 2004). The purpose of this study was to replicate and extend the clinical normative data for the RBANS for use in inpatient psychiatry. Participants were 174 inpatients from a provincial psychiatric hospital with a diagnosis of schizophrenia spectrum disorder. Median performance on the RBANS was 1-2 standard deviations (SDs) below the mean. Patients with more than 12 years of education performed significantly better on every index score than patients with 12 or fewer years of education. Men performed better than women on the Visuospatial/Constructional Index (Cohen's d= .47). When examining all five Index scores simultaneously, it was common for inpatients to obtain three or more frankly impaired scores (i.e., less than the 2nd percentile). Overall, the performance of this inpatient sample was very similar to the clinical normative data presented by Wilk et al. (2004). Detailed normative tables by diagnosis, education, and gender are provided.

Patterns and clinical correlates of neuropsychologic deficits in patients with schizophrenia

BACKGROUND/PURPOSE

Neuropsychologic deficits are prevalent among schizophrenic patients and are closely associated with pathogenesis and outcome. The pattern, extent, severity and contributing factors to such deficits remain to be examined in Taiwanese schizophrenic patients.

METHODS

A total of 122 schizophrenic patients and 94 healthy subjects for comparison were assessed by a comprehensive neuropsychologic test battery covering the eight cognitive domains of verbal ability, visual spatial ability, abstraction/execution, verbal memory, visual memory, perceptual/motor ability, mental control and attention. The relationships among cognitive deficits, demographic characteristics, clinical historical variables and clinical symptoms were further explored by multivariate regression analysis.

RESULTS

A pattern of selective deficits superimposed on a generalized deficit was found for schizophrenic patients as a group. The mean overall deficit was 1.93 standard deviations below the control mean, and abstraction/execution, verbal memory, visual memory and attention were relatively impaired among the eight cognitive domains. However, there was also marked heterogeneity in individual performances in that 24.2%, 46.2% and 29.5% of patients performed at within normal range, moderately impaired and severely impaired levels, respectively. Duration of illness substantially affected the profile and severity of the deficits, suggesting a progressive deteriorating course in neuropsychological performance. The major predictors of cognitive deficits were number of formal years of education achieved and concurrent severity of disorganization symptoms.

CONCLUSION

In a large sample of schizophrenic patients who underwent comprehensive neuropsychologic evaluation, the current results confirmed that cognitive deficits were prevalent but not a universal feature within schizophrenia. The selective impairment pattern also confirmed that such deficits were mainly in frontal and frontotemporal related functions. Despite evidence suggesting that disease chronicity entailed a decline in selective cognitive domains, the trajectory of the neuropsychologic deficits remains to be examined by further longitudinal studies.

Cognitive functioning in the early course of first-episode schizophrenia spectrum disorders: timing and patterns

OBJECTIVE

The aim of this study was to examine possible cognitive changes throughout the early course of schizophrenia spectrum disorders.

METHOD

Forty-two patients, aged 15-50 years, admitted to a first episode psychosis program (PAFIP) serving to the community of Cantabria (Spain) and 43 healthy volunteers completed a brief battery of five neurocognitive tests at four time-points over 3 months. The cognitive testing comprise five domains: attention, visuomotor speed, declarative memory, working memory and executive function. Baseline assessment occurred within 72 hour after the initiation of standard pharmacological treatment, and after then parallel forms of the tests were applied at week-2, week-6, and month-3.

RESULTS

Patient scores showed a significant impairment compared to healthy volunteers in the five cognitive domains at baseline and week-2 assessments. After the first 3 months of antipsychotic treatment, the patient group performance reached healthy volunteers level on executive function (Stroop interference) and immediate verbal memory tests. In contrast, performance on working memory, sustained attention, visuomotor speed, and verbal memory delayed recall domains still remained below healthy volunteers, although visuomotor processing speed showed a significant improvement.

CONCLUSION

Schizophrenia spectrum patients show heterogeneous patterns and degrees of cognitive changes that contribute to stress the importance of when, what, and how neurocognitive functioning in the early phases of the illness is evaluated.

Haloperidol and atypical antipsychotics share a same action of decreasing P75NTR mRNA levels in PC12 cells

P75(NTR) is a common neurotrophin receptor which binds all neurotrophins with similar affinities and has been shown to be capable of mediating programmed cell death. In this study, we investigated effects of the antipsychotic drugs (APDs) haloperidol, clozapine, quetiapine, and risperidone on p75(NTR) mRNA levels in PC12 cells. Haloperidol is a prototype of typical APDs, and the other three drugs are atypical APDs, which are effective in reducing negative symptoms and cognitive deficits of schizophrenia, cause less side effects, and are more tolerable compared to haloperidol. PC12 cells were cultured with various concentrations of haloperidol, clozapine, quetiapine, or risperidone, in their media. After culture for 48h, the cell viabilities and p75(NTR) mRNA levels were measured. It was shown that both haloperidol and the atypical APDs used in this study deceased p75(NTR) mRNA levels in PC12 cells in a dose dependent manner, while not affecting cell viabilities. In further experiments, doses that produced significant/greatest effects were chosen and provided in the culture media for various periods. Decreases in p75(NTR) mRNA levels were observed in cultures treated for 12h with quetiapine, 24h with clozapine or risperidone, or for 48h with haloperidol. These results suggest that both haloperidol and atypical APDs have the same action of decreasing p75(NTR) mRNA levels in PC12 cells. Although the underlying molecular mechanism of this action remains to be elucidated, this finding is particularly relevant given the neurodevelopmental deficits associated with schizophrenia and important roles of p75(NTR) in mediating cell death.

A double-blind, cross-over comparison of the effects of amantadine or placebo on visuomotor and cognitive function in medicated schizophrenia patients

The present study aimed to test the hypothesis that dopamine agonists may enhance cognitive function. The effect of amantadine on neuropsychological function in medicated schizophrenia patients was investigated. The study comprised an add-on, double-blind, placebo-controlled, cross-over 6-week trial. Participants comprised 29 inpatients at Sha'ar Menashe Mental Health Center who were diagnosed with chronic schizophrenia or schizoaffective disorder. Amantadine 200 mg/day or identical placebo was added to ongoing antipsychotic treatment for 3 weeks. Study medications were then switched for an additional 3 weeks. Assessments were performed at baseline, and weeks 3 and 6, including cognitive and visuomotor assessments. Clinical ratings included positive, negative and depressive symptoms and extrapyramidal side-effects. Blood prolactin levels were assayed. A mixed model was used to examine differences in the data at the three assessment points. Amantadine was associated with improved visuomotor coordination compared to placebo. No significant changes in cognitive functions were noted. Clinical symptoms, extrapyramidal side-effects and blood prolactin levels were not altered. Amantadine improved visuomotor coordination independently of extrapyramidal side-effects but not cognitive function. Because prolactin concentrations were unchanged, the mechanism is more likely to involve glutaminergic NMDA than dopaminergic mechanisms. Further studies of amantadine with different doses and treatment duration, as well as more glutamate selective agents such as memantine, are indicated.

Functional dysconnectivity in schizophrenia associated with attentional modulation of motor function

It is not known whether there is a core abnormality that occurs in all cases of schizophrenia. The cognitive dysmetria hypothesis proposes that there is such an abnormality which is characterized cognitively by a disruption in control and coordination processes, and functionally by abnormal inter-regional connectivity within the cortico-cerebellar-thalamo-cortical circuit (CCTCC). In the current study, we used functional MRI (fMRI) to investigate these two key aspects of the hypothesis. Since patients with schizophrenia show deficits in attention which have been characterized extensively using the continuous performance task (CPT) and since functional imaging studies have also demonstrated that this task engages the CCTCC, we used this task to investigate whether two patient groups with distinct symptom profiles would show functional dysconnectivity within this network. Three groups of subjects participated in the study: healthy volunteers (n = 12), schizophrenia patients with both negative and positive symptoms (n = 11) and schizophrenia patients with primarily positive symptoms (n = 11). Patient groups were matched for age of illness onset and medication, and to the control group for age, gender and handedness. Subjects were scanned using fMRI whilst they performed a modified version of the CPT, involving both degraded and non-degraded stimuli. Stimulus degradation has been shown to produce decrements in sensitivity, which is thought to reflect increased demands on the limited capacity of visual attention. Between-group comparisons revealed that patients with schizophrenia, irrespective of symptomatology, showed attenuation of the anterior cingulate and cerebellar response to stimulus degradation in comparison with control subjects. We also observed disruptions of inter-regional brain integration in schizophrenia. A task-specific relationship between the medial superior frontal gyrus and both anterior cingulate and the cerebellum was disrupted in both patient groups in comparison with controls. In addition, patients with negative symptoms showed impaired behavioural performance, and abnormal task-related connectivity between anterior cingulate and supplementary motor area. These findings are consistent with theoretical accounts of schizophrenia as a disorder of functional integration, and with the cognitive dysmetria hypothesis, which posits a disconnection within the CCTCC as a fundamental abnormality in schizophrenia, independent of diagnostic subtype. Furthermore, these data show evidence of additional functional deficits in patients with negative symptoms, deficits which may explain the accompanying attentional impairment.

Cognitive dysfunctions in medicated and unmedicated patients with recent-onset schizophrenia

Schizophrenia is associated with impairments in many cognitive domains on which the influence of antipsychotics, whether conventional or atypical, remains unclear. We conducted a study of recent-onset schizophrenic patients (DSM IV) that included unmedicated (n=19), and medicated (n=19) patients matched for age and IQ. Both groups of patients had comparably low extra-pyramidal symptoms (EPS). Cognitive tasks included attentional tasks (alertness and divided attention tests), a working memory task (a verbal n-back test) and the Wisconsin Card Sorting Test (WCST). After adjustment for the Total PANSS score, we found no significant difference between the two groups of patients in any of the cognitive tasks. When compared to a group of healthy controls (n=20) matched for IQ level, unmedicated patients performed significantly worse in all cognitive tasks, with significantly longer reaction times for alertness, divided attention and working memory. These results confirm the presence of cognitive impairments in attentional and executive functions in recent-onset patients whether or not they are medicated. There was no evidence that either conventional or atypical antipsychotics had an influence on patients when EPS were excluded. Altogether, our results further support the idea that cognitive deficits in schizophrenia are enduring features per se and cannot be considered as secondary to psychiatric symptoms or to the adverse effects of medication. In addition our results suggest that antipsychotics do not have a major effect on these impairments.

The Primacy of Cognition in Schizophrenia

Cognitive tasks and concepts are used increasingly in schizophrenia science and treatment. Recent meta-analyses show that across a spectrum of research domains only cognitive measures distinguish a majority of schizophrenia patients from healthy people. Average effect sizes derived from common clinical tests of attention, memory, language, and reasoning are twice as large as those obtained in structural magnetic resonance imaging and positron emission tomography studies. Chronic stress, genes, brain disturbances, task structure, gender, and sociocultural background may all enhance the sensitivity of cognitive performance to schizophrenia. At the same time, disease heterogeneity and the presence of endophenotypes and subtypes within the patient population may place upper limits on the strength of any specific cognitive finding. Schizophrenia is a complex biobehavioral disorder that manifests itself primarily in cognition.

Lack of behavioural effects after acute tyrosine depletion in healthy volunteers

Acute dietary tyrosine depletion has previously been shown to reduce dopamine neurotransmission in both animals and humans. In this study, we investigated the effects of brain dopamine depletion, through acute tyrosine and phenylalanine depletion, on plasma prolactin, mood and neuropsychological function in 12 normal subjects. In a randomized, double-blind, cross-over design, subjects received two amino-acid drinks separated by a week, a nutritionally balanced mixture (Bal) and on the other occasion a tyrosine and phenylalanine deficient mixture (TP-). The plasma ratio of tyrosine and phenylalanine to the other large neutral amino acids decreased significantly on the TP- occasion (-78.7%, p < 0.0001) and there was an increase in plasma prolactin concentration relative to the balanced drink in the seven subjects for whom results were available for both occasions (p < 0.02). Acute tyrosine depletion did not alter mood as measured by visual analogue scale ratings, and measures of memory, attention and behavioural inhibition were also unaffected. Our results are consistent with acute dietary tyrosine depletion causing a reduction in brain dopamine neurotransmission but raise questions about how robust or consistent the effects are on psychological function.

Comparing efficacy of first-line atypical antipsychotics: no evidence of differential efficacy between risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole

Objective To evaluate the comparative efficacy of the first-line atypical antipsychotics risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole. Methods We reviewed published short-term, randomised, controlled clinical trials of first-line atypical antipsychotics in the treatment of schizophrenia or schizoaffective disorder that used the Positive and Negative Syndrome Scale to assess efficacy. We used a combined overview analysis to compare the extent of improvement in global symptoms and positive and negative symptoms. We did not analyse adverse event data. Results Although we found considerable variation in the degree of improvement with a particular atypical antipsychotic across different studies, the range and average improvement were similar among all first-line atypicals for all efficacy parameters considered. Dosage was a critical determinant of efficacy, although the most effective dose of each agent varied across studies. There were insufficient data for ziprasidone and aripiprazole to allow their inclusion in the formal overview comparison. Conclusion Despite confounding and methodological limitations, the data we reviewed do not support assertions of differential efficacy between the first-line atypical antipsychotics. Additional controlled comparative studies of the atypical antipsychotics should be of particular interest.

Correlates of subjective well-being in schizophrenic patients treated with atypical antipsychotics

Objective A growing body of research indicates that a low subjective well-being (SW) may be predictive of non-adherence and less favourable outcome. This study examined baseline variables and variables in the course of treatment hypothesised to be associated with later SW. Methods Sixty-three inpatients with schizophreniform disorder or schizophrenia were randomly assigned to treatment with various atypical antipsychotics after a wash-out phase of 2 days. Subjects were evaluated with a protocol that examined psychopathology (Positive and Negative Symptom Scale, PANSS), side effects (Scandinavian Society of Pharmacology, UKU), and subjective well-being (Subjective Well-being under Neuroleptic treatment, SWN) at baseline and endpoint (mean duration of treatment 39.9 days). Two-thirds of subjects were multiple episode schizophrenic inpatients pre-treated with antipsychotics. Results Multiple regression analyses revealed that the PANSS negative score, neurological side effects, and SWN at baseline, as well as change of the PANSS positive score between baseline and endpoint, were associated independently with SW at endpoint (R(2)=0.55 after exclusion of two subjects). Conclusions Patients with low SW, severe negative symptoms, and neurological side effects, all at baseline, as well as those without improvement or deterioration of positive symptoms are at risk of low SW later in treatment and, most likely, of non-adherence.

The catechol-O-methyltransferase polymorphism: relations to the tonic-phasic dopamine hypothesis and neuropsychiatric phenotypes

Diverse phenotypic associations with the catechol-O-methyltransferase (COMT) Val158Met polymorphism have been reported. We suggest that some of the complex effects of this polymorphism be understood from the perspective of the tonic-phasic dopamine (DA) hypothesis. We hypothesize that the COMT Met allele (associated with low enzyme activity) results in increased levels of tonic DA and reciprocal reductions in phasic DA in subcortical regions and increased D1 transmission cortically. This pattern of effects is hypothesized to yield increased stability but decreased flexibility of neural network activation states that underlie important aspects of working memory and executive functions; these effects may be beneficial or detrimental depending on the phenotype, a range of endogenous factors, and environmental exigencies. The literature on phenotypic associations of the COMT Val158Met polymorphism is reviewed, highlighting areas where this hypothesis may have explanatory value, and pointing to possible directions for refinement of relevant phenotypes and experimental evaluation of this hypothesis.

Maintenance of long-term efficacy and safety of quetiapine in the open-label treatment of schizophrenia

As schizophrenia is a chronic disorder, it is important that treatment be given over a long period of time to avoid relapse. Quetiapine, an atypical antipsychotic, has established efficacy and good tolerability in the short-term treatment of schizophrenia. This study investigated the long-term efficacy and safety of quetiapine in 674 patients with schizophrenia using combined data from the open-label extension phase of four Phase IIIa trials. The results showed that quetiapine, at a mean daily dose of 472.4 mg, provided progressive improvement and maintenance in the Brief Psychiatric Rating Scale total, positive- and negative-symptoms cluster, Clinical Global Impression Severity of Illness, and Scale for the Assessment of Negative Symptoms total scores over 208 weeks and beyond. Furthermore, quetiapine was well tolerated throughout the study period, with a low incidence of extrapyramidal symptom-related adverse events. In conclusion, quetiapine may be a suitable therapy in the long-term treatment of schizophrenia.

Schizophrenia: from phenomenology to neurobiology

Schizophrenia is a common and debilitating illness, characterized by chronic psychotic symptoms and psychosocial impairment that exact considerable human and economic costs. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, treatment, genetics and neurobiology of schizophrenia. Although studied extensively from a clinical, psychological, biological and genetic perspective, our expanding knowledge of schizophrenia provides only an incomplete understanding of this complex disorder. Recent advances in neuroscience have allowed the confirmation or refutation of earlier findings in schizophrenia, and permit useful comparisons between the different levels of organization from which the illness has been studied. Schizophrenia is defined as a clinical syndrome that may include a collection of diseases that share a common presentation. Genetic factors are the most important in the etiology of the disease, with unknown environmental factors potentially modulating the expression of symptoms. Schizophrenia is a complex genetic disorder in which many genes may be implicated, with the possibility of gene-gene interactions and a diversity of genetic causes in different families or populations. A neurodevelopmental rather than degenerative process has received more empirical support as a general explanation of the pathophysiology, although simple dichotomies are not particularly helpful in such a complicated disease. Structural brain changes are present in vivo and post-mortem, with both histopathological and imaging studies in overall agreement that the temporal and frontal lobes of the cerebral cortex are the most affected. Functional imaging, neuropsychological testing and clinical observation are also generally consistent in demonstrating deficits in cognitive ability that correlate with abnormalities in the areas of the brain with structural abnormalities. The dopamine and other neurotransmitter systems are certainly involved in the treatment or modulation of psychotic symptoms. These broad findings represent the distillation of a large body of disparate data, but firm and specific findings are sparse, and much about schizophrenia remains unknown.

Adverse drug reactions associated with antipsychotics, antidepressants, and mood stabilizers

This article on major ADRs associated with psychotropic agents has overviewed major side effects of conventional and novel medications. Nursing interventions that focus on prevention, early identification, accurate diagnosis and appropriate interventions are crucial to treatment outcomes.

Efficacy of newer generation antipsychotics in the treatment of schizophrenia

The advent of the newer 'atypical' antipsychotic medications has revolutionized the pharmacologic treatment of schizophrenia and other psychotic disorders. In contrast to the older conventional antipsychotic agents, atypical medications have a broader spectrum of efficacy (greater efficacy in negative, cognitive, and mood symptoms) and a lower risk of extrapyramidal symptoms (EPS) and tardive dyskinesia. Due to concerns surrounding hematological safety and other adverse effects, clozapine is used principally in patients refractory to treatment with other antipsychotic agents. The other three universally available atypical agents (risperidone, olanzapine, and quetiapine) collectively constitute about 70% of all antipsychotic prescriptions in the USA. Despite the broad popularity of these medications and their rapid adoption in general clinical practice, there are limited data on how they compare to each other with regards to their overall efficacy and also as to their efficacy in specific symptom domains. To address this question, two separate analyses were undertaken. First, all published, short-term, randomized, controlled clinical trials of these agents in schizophrenia and schizoaffective disorder were reviewed and the extent of improvement across these agents was compared. While the amount of improvement with a particular agent across its different studies varied, the average improvement was similar for the agents for all efficacy parameters considered. Secondly, all randomized, controlled clinical trials directly comparing two or more of these agents in patients with schizophrenia or schizoaffective disorder were analyzed. Only three such trials (all industry sponsored) were identified; while there were differences in methodology and small differences in efficacy on a minority of measures on which comparisons were undertaken, the preponderance of data suggested no differences in efficacy. While data thus far do not support assertions of differential efficacy between risperidone, olanzapine, and quetiapine, there are clear differences in their side-effect profiles and these are briefly summarized.

Effects of the 5-HT2A agonist psilocybin on mismatch negativity generation and AX-continuous performance task: implications for the neuropharmacology of cognitive deficits in schizophrenia

Previously the NMDA (N-methyl-D-aspartate) receptor (NMDAR) antagonist ketamine was shown to disrupt generation of the auditory event-related potential (ERP) mismatch negativity (MMN) and the performance of an 'AX'-type continuous performance test (AX-CPT)--measures of auditory and visual context-dependent information processing--in a similar manner as observed in schizophrenia. This placebo-controlled study investigated effects of the 5-HT(2A) receptor agonist psilocybin on the same measures in 18 healthy volunteers. Psilocybin administration induced significant performance deficits in the AX-CPT, but failed to reduce MMN generation significantly. These results indirectly support evidence that deficient MMN generation in schizophrenia may be a relatively distinct manifestation of deficient NMDAR functioning. In contrast, secondary pharmacological effects shared by NMDAR antagonists and the 5-HT(2A) agonist (ie disruption of glutamatergic neurotransmission) may be the mechanism underlying impairments in AX-CPT performance observed during both psilocybin and ketamine administration. Comparable deficits in schizophrenia may result from independent dysfunctions of 5-HT(2A) and NMDAR-related neurotransmission.

Managing treatment-resistant schizophrenia: evidence from randomized clinical trials

Clozapine was the first antipsychotic medication to be approved for the indication of treatment-refractory schizophrenia. This followed rigorous testing in patients who retrospectively and prospectively failed treatment trials of relatively high doses of conventional antipsychotics. In the past decade, other atypical antipsychotics have been approved, but they have not been designated specifically for patients with a history of prior poor treatment response. Better tolerated than clozapine, these new agents have been used with varying success in patients who would have otherwise received clozapine. Up until very recently there has not been a head-to-head controlled clinical trial comparing the two most commonly used atypical antipsychotics, risperidone and olanzapine, with clozapine in patients considered to have a suboptimal response to typical antipsychotics. This review summarizes the current advances made in the pharmacological management of these patients by examining recently published randomized controlled clinical trials that have measured psychopathology and cognition.

Basal ganglia volumes in first-episode schizophrenia and healthy comparison subjects

BACKGROUND

Previous studies suggest that dysfunction of cortico-striato-pallido-thalamic (CSPT) circuitry may be involved in the pathophysiology of schizophrenia but also show that basal ganglia structure is highly plastic and may be influenced by antipsychotic treatments. Controversy remains about whether basal ganglia pathology can be detected in vivo among treatment-naïve patients. We conducted a magnetic resonance imaging (MRI) study to examine basal ganglia structures and the limbic forebrain in first episode schizophrenia and healthy comparison subjects.

METHODS

Fifty-one patients with first-episode schizophrenia and 28 healthy comparison subjects participated in the study. A high-resolution, special contrast (white matter nulling) MRI sequence was used to measure the caudate nucleus, nucleus accumbens, putamen, and subcommissural limbic forebrain.

RESULTS

Volumes of the basal ganglia regions of interest (adjusted for total brain volume and age) did not differ significantly between the groups. Age correlated significantly with caudate and putamen volumes bilaterally in the healthy comparison group, but not among patients.

CONCLUSIONS

The findings suggest that there are no volumetric abnormalities in basal ganglia before treatment in first-episode schizophrenia. The lack of a negative correlation between age and striatal volume among patients may implicate illness-associated factors that alter normal age-related changes in basal ganglia size.

Negative symptom resolution and improvements in specific cognitive deficits after acute treatment in first-episode schizophrenia

Patients with first-episode schizophrenia show significant cognitive impairments even at this early phase of their illness. Antipsychotic medication improves clinical symptomatology, but the effectiveness of this treatment on neuropsychological deficits remains unclear. We investigated clinical symptom and neuropsychological performance change in 34 unmedicated first-episode psychotic patients (17 males, 17 females) from the time prior to treatment until 33.6+/-11.3 days after treatment initiation at which time patients demonstrated meaningful recovery from psychosis. Twenty-four matched healthy subjects were also studied. Performance in most neuropsychological functions (language skills, attention, nonverbal learning and reasoning, motor speed) remained stable for the group as a whole. However, reduction in negative symptoms was significantly correlated with performance increases in verbal fluency and attention. Higher negative symptom recovery was associated with improvement of cognitive performance to levels approaching those of healthy subjects, whereas low or no negative symptom improvement was associated with stable or decreased cognitive performance. Reduction in positive symptoms was not associated with change in cognitive abilities. These findings suggest a linkage between early, treatment-induced improvements in negative symptoms and reductions in distinct cognitive deficits.

Arithmetic fact retrieval and working memory in schizophrenia

Despite its importance in every-day life and vocational rehabilitation, arithmetic ability has rarely been investigated in schizophrenic patients. Those few studies reporting arithmetic deficits in schizophrenia, however, administered complex calculation tasks which drew not only on arithmetic abilities, but also on working memory resources known to be impaired in schizophrenia. In the present study, arithmetic abilities and working memory functions were investigated in schizophrenic patients (n=24) and healthy control subjects (n=24). Arithmetic fact retrieval was assessed in single-digit multiplication and corresponding division problems using a result verification task which minimized working memory demands. Problem size and the disparity of the proposed result were manipulated. The storage component of working memory was tested with a digit span forward task and the executive control component with a digit span backward as well as with verbal fluency tasks. Schizophrenic patients performed worse than controls only in the executive tasks. Digit span forward was preserved. In the arithmetic tasks, groups did not differ from each other, and a similar pattern of task manipulations was obtained. Hence, despite the executive control deficit retrieval of arithmetic facts is preserved in schizophrenia. Moreover, the same underlying cognitive processes as in control subjects are involved.

Pharmacologic treatment of schizophrenia: what the future holds

The advent of the newer "atypical" antipsychotics has revolutionized pharmacologic treatment of schizophrenia (SZ) and other psychotic disorders. In contrast to the first-generation conventional neuroleptics, these second-generation antipsychotic agents possess a broader spectrum of efficacy and cause fewer motor side effects such as extrapyramidal symptoms and tardive dyskinesia. Despite their substantial advantages, however, these second-generation agents also have significant limitations in terms of both efficacy and adverse effects. Several strategies to address these shortcomings are currently under study and some of these are likely to become part of our therapeutic armamentarium in the future. Current shortcomings in the pharmacologic treatment of SZ and strategies under investigation to address each of these deficiencies are reviewed. New formulations of existing medications and new antipsychotics under development are discussed. Developing adjunctive treatment strategies to address each of the major psychopathologic domains in SZ are summarized. The potential application of genetic information to treatment-matching in SZ is reviewed and likely refinements in the practice of evidence-based medicine in the pharmacotherapy of SZ are considered.

Quetiapine: efficacy and tolerability in schizophrenia

Quetiapine, in common with clozapine, has a greater affinity for 5-HT(2) receptors than D(2) receptors and preclinical studies have consistently predicted efficacy against schizophrenia, with a low potential for causing extrapyramidal symptoms (EPS). In clinical trials, the efficacy of quetiapine was consistently superior to placebo and it was effective against both positive and negative symptoms. Quetiapine was also at least as effective as chlorpromazine or haloperidol in improving the symptoms of acute schizophrenia and moreover was associated with higher response rates. The consistent, placebo-level incidence of EPS associated with quetiapine in clinical trials was not seen with haloperidol. Thus, the combination of efficacy comparable to other antipsychotic agents, with an acceptable side effect and tolerability profile, provides support for the use of quetiapine as a first-line antipsychotic agent in the long-term treatment of schizophrenia.

Quetiapine--efficacy in different domains

Conventional treatment paradigms for schizophrenia have typically focused on reducing positive symptomatology; however, it is increasingly apparent that negative and cognitive symptoms are also important treatment targets. Cognitive function, in particular, is known to affect multiple outcome domains, including performance of basic daily activities, and social and occupational functioning. While traditional antipsychotics have little, or even a detrimental, effect on neurocognitive impairment in patients with schizophrenia, available data suggest that cognitive function may be improved during treatment with atypical antipsychotics. Quetiapine is a novel atypical antipsychotic with proven efficacy in schizophrenia across all domains. Results of well-controlled, double-blind, randomised studies show quetiapine to significantly improve cognitive function compared with treatment with haloperidol. Quetiapine has also been shown to be effective and well tolerated in patients particularly vulnerable to the extrapyramidal side effects (EPS) associated with conventional antipsychotics, making it well suited for use as first-line therapy.

Effects of olanzapine and other antipsychotics on cognitive function in chronic schizophrenia: a longitudinal study

This study aimed to determine the effect of olanzapine and other antipsychotic drugs on cognitive functions after 6months of treatment. Baseline, 3month and 6month psychopathological and cognitive evaluations were made. Thirty-eight partially responsive outpatients with DSM-IV chronic schizophrenia diagnosis were included in the study. On the indication of their attending psychiatrists, 21 patients initiated treatment with olanzapine, and 17 remained on their previous treatment with other antipsychotic drugs. Cognitive assessments were blind to medication and psychopathological status. The olanzapine group presented a significantly greater improvement in negative symptomatology and verbal memory than the comparison group in repeated-measures of MANOVAs between baseline, 3month and 6month assessments. These differences remained statistically significant after covarying out gender, treatment with other atypical antipsychotics, biperidene doses and changes in positive and negative symptoms. In order to match previous differences between groups, cognitive baseline scores for each test were introduced as covariates, resulting in a significant improvement for the olanzapine group in negative symptomatology and the interference task of the Stroop test.We then re-analyzed the data, dividing the comparison group into two groups: risperidone-treated patients (n=9) and patients receiving conventional antipsychotic drugs (n=8). Post-hoc analyses between groups were carried out with baseline cognitive assessment as covariate. The olanzapine group improved significantly more than the risperidone group in negative symptomatology and in the interference task of Stroop test. The improvement in the number of categories of the Wisconsin Card Sorting Test was higher in risperidone patients than in those receiving olanzapine or conventional antipsychotic treatment. Conventional antipsychotic drugs did not present a significant improvement over atypical antipsychotic drugs in any cognitive function. In summary, in patients suffering from chronic schizophrenia, atypical antipsychotic agents were associated with slight differential improvements over time in attentional, verbal memory and executive functions compared with conventional neuroleptic drugs. No differential improvements were found in social functioning, verbal fluency, non-verbal domains of memory or visuo-motor abilities.

The timing of neurodevelopmental abnormality in schizophrenia: an integrative review of the neuroimaging literature

In this paper we will review recent neuroimaging research in schizophrenia, with an aim to critically evaluate several recent proposals concerning the nature and the timing of the neuroanatomic abnormalities underlying the disorder. Specifically, enlargement of cerebrospinal fluid spaces, deficits in cortical gray matter, and reduced volume of mesiotemporal structures have all been reported in patients in the first episode of schizophrenia, their first-degree relatives, and individuals with schizotypal personality disorder, supporting the possibility that these abnormalities reflect a genetically mediated neurodevelopmental disorder. These findings from the empirical literature will be synthesized from the perspective of dual cytoarchitectonic trends theory of neurodevelopment, as well as in relation to current conceptions of the schizophrenia prodrome. We believe that the evidence shows that sufficient groundwork has been laid to begin longitudinal neuroimaging studies of adolescents at clinical risk for schizophrenia, in order to more definitively determine the pathophysiology of the disorder. Such information could have significant implications in terms of understanding the prediction, treatment, and ultimately the prevention of schizophrenia.

Neuropsychological change in schizophrenia after 6 weeks of clozapine

Neuropsychological change after 6weeks of clozapine treatment was examined in 18 treatment-refractory patients to test anticipated domain-specific cognitive improvements. The first aim of this study was to test the assumption that increased homogeneity of sample and treatment would yield an experimental design with sufficient sensitivity to detect general intellectual changes with clozapine that were not apparent in one previous investigation. The second aim was to test predictions derived from a domain-specific review of all other investigations with clozapine suggesting salient gains on tests sensitive to motor and mental speed, visual spatial manipulation, and new learning of verbal material. The results showed that the comprehensive neuropsychological test battery was sensitive to general cognitive changes with clozapine, and supported the hypothesized domain-specific gains on tests of motor and mental speed, visual spatial manipulation and new verbal learning. Novel gains were also apparent on tests of new learning with nonverbal material. The results are discussed in relation to aspects of experimental design necessary for the evaluation of prospective medication-induced changes in cognitive skill, particularly in future investigations designed to differentiate between second-generation antipsychotic medications.

A preliminary study of the comparative effects of olanzapine and fluphenazine on cognition in schizophrenic patients

The aim of the study was to compare the effect of olanzapine versus fluphenazine treatment on cognitive functioning. Eighteen schizophrenic outpatients, aged 25 - 61 (average 37 years), all meeting DSM-IV diagnostic criteria for schizophrenia, were included in the study. They were randomly assigned to 22 weeks of either olanzapine or fluphenazine treatment. Certain subscales of the Wechsler Adult Intelligence Scale, the Stroop Neuropsychological Screening Test and the Wisconsin Card Sorting Test were performed. Olanzapine treatment proved to have a beneficial effect on digit-symbol performance and some aspects of executive function. In comparison to the fluphenazine treatment, the olanzapine treatment only showed a beneficial effect in increased percentage of conceptual level responses. Although the results are preliminary, they could implicate that the benefit of olanzapine treatment is primarily related to certain aspects of executive function, i.e. frontal lobe functioning. Copyright 2000 John Wiley & Sons, Ltd.

Reduced anterior cingulate gyrus volume correlates with executive dysfunction in men with first-episode schizophrenia

Although frontal lobe structural and functional abnormalities have been identified in schizophrenia, their relationship remains elusive. Because the frontal lobes are both structurally and functionally heterogeneous, it is possible that some measures of frontal lobe structure may not have accurately identified relevant frontal lobe subregions. The authors hypothesized that the volumes of two dorsal, 'archicortical' subregions (i.e. superior frontal gyrus and anterior cingulate gyrus), but not a ventral, 'paleocortical' subregion (i.e. orbital frontal region) would be significantly and selectively correlated with executive and motor dysfunction in patients with schizophrenia as previously reported for the anterior hippocampal region. Volumes of these frontal lobe subregions were measured from magnetic resonance images based on sulcal anatomy in 20 men and 15 women with first-episode schizophrenia. All patients completed a comprehensive neuropsychological test battery while clinically stabilized that encompassed six domains of functioning: attention, executive, motor, visuospatial, memory and language. Findings indicated that reduced anterior cingulate gyrus volume was significantly correlated with worse executive functioning in men; among women, there were no significant correlations. Among men, anterior cingulate gyrus volume was significantly more strongly correlated with executive functioning than with attention, visuospatial, memory, language and general intellectual functioning. Neither executive nor motor functioning was significantly more strongly correlated with the dorsal 'archicortical' volumes than with orbital frontal volume. These findings suggest a link between executive deficits and dysfunction of the dorsal 'archicortical' system and implicate sex differences in their relationship in first-episode schizophrenia.

Review of quetiapine and its clinical applications in schizophrenia

Preclinical studies have shown that quetiapine (Seroquel, AstraZeneca) is an atypical antipsychotic with many similarities to clozapine. Both placebo-controlled and comparative studies in patients with schizophrenia have demonstrated that quetiapine has long-term efficacy in both positive and negative domains, as well as beneficial effects on affective and cognitive symptoms. Comparative clinical studies confirm that quetiapine is at least as effective as the standard antipsychotics, chlorpromazine and haloperidol and response rates with quetiapine are similar to those reported with other atypical antipychotics. Quetiapine has also demonstrated superior efficacy to haloperidol in partially responsive patients, who can be particularly difficult to treat. Quetiapine has a wide clinical dosing range (150-750 mg/day), although doses of 400 mg or above should be used in patients who do not fully respond to lower doses of the drug. Quetiapine is generally well tolerated with no requirement for routine ECG or blood monitoring and it has minimal effects on weight. Uniquely among other first-line atypical antipsychotics, quetiapine is associated with a placebo-level incidence of EPS and an indistinguishable effect from placebo on plasma prolactin at all doses. Thus, clinicians can confidently increase the dose of quetiapine, without increasing the risk of EPS or hyperprolactinaemia. A number of studies have also shown that quetiapine is well-tolerated and effective in patients who are particularly susceptible to EPS, including elderly and adolescent patients and those with pre-existing dopaminergic pathology, such as Alzheimer's disease and Parkinson's disease. The consistent efficacy in treating all schizophrenic domains and good tolerability, particularly placebo-level EPS, make quetiapine acceptable to patients, as demonstrated in a survey of patient satisfaction. Thus quetiapine is a suitable first-line therapy for the treatment of schizophrenia and psychosis.

Neuropsychological deficits in pediatric patients with childhood-onset schizophrenia and psychotic disorder not otherwise specified

OBJECTIVE

Children with transient psychotic symptoms and serious emotional disturbances who do not meet current criteria for schizophrenia or other presently recognized diagnostic categories commonly present diagnostic and treatment problems. Clarifying the connections between children with narrowly defined schizophrenia and children with a more broadly defined phenotype (i.e., Psychotic Disorder Not Otherwise Specified, PD-NOS) has implications for understanding the pathophysiology of schizophrenia. In this study, the neuropsychological test performance of a subgroup of children with atypical psychosis was compared with that of patients with childhood-onset schizophrenia (COS).

METHOD

Cognitive function was assessed with neuropsychological test battery regimens in 51 neuroleptic-nonresponsive patients within the first 270 at NIMH testing (24 PD-NOS, 27 COS) were included in this analysis. Seventeen (39%) of 44 COS subjects were unavailable for this study as their IQ tested <70. The PD-NOS patients were younger than the COS patients at the time of testing (12.0+/-2.8 vs 14.4+/-1.8years, respectively, p<0.004). The test levels of these groups were compared with each other.

RESULTS

The neuropsychological test results for the PD-NOS and COS patients were 1-2standard deviations below normative data across a broad array of cognitive functions. There were no overall differences in the test levels for the six summary scales (F=2.82, df=1, 36, p=0.10) or in the profile shape (F=1.70, df=5, 180, p=0.14) between the PD-NOS and COS groups. For the COS patients, there was a significant difference between their mean full-scale WISC IQ (84.7+/-16.2) and their average standard scores for both the spelling (97.7+/-16.1, n=23, t=4.0, p=0.001) and reading decoding subtests (97.7+/-13.7, n=23, t=3.7, p=0.001) of the Kaufman Test of Educational Achievement.

CONCLUSIONS

Treatment-refractory PD-NOS and COS patients share a similar pattern of generalized cognitive deficits, including deficits in attention, learning and abstraction which are commonly observed in adult patients with schizophrenia. These data support a hypothesis that at least some of the PD-NOS cases belong within the schizophrenic spectrum, which is of importance for future genetic studies planned for this cohort.

Dual cytoarchitectonic trends: an evolutionary model of frontal lobe functioning and its application to psychopathology

OBJECTIVE

To introduce and discuss an evolutionary model of frontal lobe functioning (the dual cytoarchitectonic trends theory [DTT]) and its application to understanding the neurobiology of schizophrenia and anxiety disorders.

METHOD

An introduction to the DTT with respect to neural architecture, connectivity, and function is presented. In addition, neurobiologic, neuropathologic, clinical, and cognitive research supporting the application of this model to schizophrenia and anxiety disorders is reviewed.

RESULTS

Traditional neuropsychologic models of acquired brain damage have been limited in their ability to explain frontal lobe dysfunction and its consequences in relation to psychopathology. The DTT offers an appropriately general neural-systems framework that may be better able to account for the diversity of symptoms, widespread neuropathology, and developmental abnormalities that are associated with most forms of psychopathology.

CONCLUSIONS

Research investigating the neurobiology of psychopathology would benefit from adopting models of brain dysfunction that are consistent with neurodevelopmental pathology and evolution. Such efforts would likely lead to a greater understanding of neurobiologic mechanisms and, ultimately, better treatment strategies.

The importance of treatment acceptability to patients

Antipsychotic drug treatment plays a central role in the care of patients with schizophrenia. The chronic nature of the illness means that most patients are likely to require long-term antipsychotic medication to alleviate symptoms and to prevent recurrence of an acute psychotic episode. Unfortunately, a high proportion of patients with schizophrenia do not comply with medication and this has profound consequences in terms of the number and severity of relapse episodes, rehospitalization rates, worsening of residual symptoms and social costs, including substance misuse, homelessness and the burden on carers. Ensuring that antipsychotic treatment is acceptable to the patient is fundamental to managing adherence. Side-effects, particularly mental and extrapyramidal symptoms (EPS), are the cause of much distress to patients and dissatisfaction with treatment, so a treatment regimen with a low side effect profile will help to improve adherence to the treatment. Such regimens have unmasked many of the other side-effects of treatment that were previously viewed as subsidiary to EPS; but the physical and psychological consequences of side-effects such as antipsychotic-induced sexual dysfunction or weight gain are highly distressing to the patient, and as likely as EPS to trigger non-adherence to medication. Consequently, careful selection of antipsychotic agent and dose regimens is essential to maximize the efficacy of the antipsychotic and to minimize the overall burden of side-effects. Satisfaction also depends very much on the extent to which the patient understands the treatment and its side-effects. Therefore, a close therapeutic alliance between the patient and the psychiatrist must underpin all attempts to increase the acceptability of treatment. This will allow the clinician to determine how the illness and its treatment are affecting all aspects of the life of the patient, and then to tailor the treatment continuously to obtain the best possible outcome for the patient.

Longitudinal assessment of methylphenidate effects on oral word production and symptoms in first-episode schizophrenia at acute and stabilized phases

BACKGROUND

Some studies have reported psychotic symptom exacerbation during "pharmacologic challenge" paradigms using dopamine agonists. Few studies, however, have examined the effects of these agonists on neurocognitive functions in patients with schizophrenia. This study assessed the effects of methylphenidate infusion on an oral word production test with demonstrated sensitivity to frontal lobe lesions, and on clinical state.

METHODS

Patients were tested at two different phases; at the onset of their first-episode of schizophrenia (acute phase), and then again after they had responded to treatment and were clinically stable (stabilization phase). During each phase, patients were tested prior to and following methylphenidate infusion. Symptom clusters (i.e., positive, negative, and disorganization) were formed from SANS and SADS-C (+PD) ratings at each of these four timepoints.

RESULTS

Patients produced significantly more words at preinfusion and while stabilized, suggesting that overall, decreased dopamine activity was associated with better word production. Redundant errors (i.e., perseverations of previously mentioned words and production of multiple words with the same roots) increased significantly following infusion in the stabilized phase. Disorganization symptoms increased significantly following infusion, regardless of study phase.

CONCLUSIONS

These findings are consistent with previous theoretical and empirical findings relating dopamine activity to verbal output, a "redundancy bias" in cognitive control, and exacerbation of disorganization symptoms.

Investigation of frontal lobe subregions in first-episode schizophrenia

The evidence for frontal lobe structural abnormalities in schizophrenia using magnetic resonance (MR) imaging has been mixed, but most studies used either single slice measures or total volumes of a single frontal region, neither of which is sensitive to potential volume differences in more specific subregions. This study employed reliable methods for parcellation of the frontal lobes from MR images based on the sulcal anatomy. Following a cytoarchitectonic theory that distinguishes dorsomedial (archicortically derived) from ventrolateral (paleocortically derived) frontal subregions, we measured the superior frontal gyrus, anterior cingulate gyrus, and orbital frontal region in 19 first-episode schizophrenia patients and 26 healthy comparison subjects. Results indicated that male patients had significantly larger right orbital frontal volume compared to their left orbital frontal volume and compared to healthy men. Among male patients larger right orbital frontal volume was significantly correlated with smaller right 'archicortical' (i.e. anterior cingulate and superior frontal gyri) volume. Furthermore, the ratio of right orbital frontal to right 'archicortical' volume was significantly and positively correlated with level of delusions among male patients. These findings suggest that there may be reciprocal controls on 'archicortical' and 'paleocortical' neurodevelopment among men with schizophrenia, and that larger paleocortical relative to archicortical volumes may be associated with increased delusions.

The use of clock tests in schizophrenia

Though clock drawing tests are well recognized as measures of cognitive function, there is little data on the performance of patients with schizophrenia. We compared 24 patients with schizophrenia to 24 healthy, age-matched controls on clock drawing, copying, and reading. Patients with schizophrenia performed significantly worse on clock drawing and copying despite the fact that the groups had similar scores on the MMSE. Worse performance was associated with higher scores on the BPRS. Clock drawing and copying may be useful for the assessment of cognition in schizophrenia, and the monitoring of cognitive changes associated with antipsychotic medication.