Efficacy of olanzapine versus quetiapine on cognitive dysfunctions in patients with an acute episode of schizophrenia

Short-term Medication Effects on Brain Functional Activity and Network Architecture in First-Episode psychosis: a longitudinal fMRI study

The effect of antipsychotic medications is critical for the long-term outcome of symptoms and functions during first-episode psychosis (FEP). However, how brain functions respond to the antipsychotic treatment in the early stage of psychosis and its underlying neural mechanisms remain unclear. In this study, we explored the cross-sectional and longitudinal changes of regional homogeneity (ReHo), whole-brain functional connectivity, and network topological properties via resting-state functional magnetic resonance images. Thirty-two drug-naïve FEP patients and 30 matched healthy volunteers (HV) were included, where 23 patients were re-visited with effective responses after two months of antipsychotic treatment. Compared to HV, drug-naive patients demonstrated significantly different patterns of functional connectivity involving the right thalamus. These functional alterations mainly involved decreased ReHo, increased nodal efficiency in the right thalamus, and increased thalamic-sensorimotor-frontoparietal connectivity. In the follow-up analysis, patients after treatment showed reduced ReHo and nodal clustering in visual networks, as well as disturbances of visual-somatomotor and hippocampus-superior frontal gyrus connectivity. The longitudinal changes of ReHo in the visual cortex were associated with an improvement in general psychotic symptoms. This study provides new evidence regarding alterations in brain function linked to schizophrenia onset and affected by antipsychotic medications. Moreover, our results demonstrated that the functional alterations at baseline were not fully modulated by antipsychotic medications, suggesting that antipsychotic medications may reduce psychotic symptoms but limit the effects in regions involved in disease pathophysiology.

Quetiapine attenuates the acquisition of morphine-induced conditioned place preference and reduces ERK phosphorylation in the hippocampus and cerebral cortex

Background: Quetiapine is an atypical antipsychotic that antagonizes dopamine and serotonin receptors. It has been suggested that quetiapine can be used to treat substance use disorders, including opioid use disorder. Opioids modulate dopaminergic functions associated with conditioned reinforcement and these effects can be measured via the conditioned place preference (CPP) paradigm. Opioids' unconditioned effects are regulated by several proteins, including extracellular signal-regulated kinase (ERK) and cAMP-responsive element-binding (CREB).Objective: To assess the effect of quetiapine on morphine-induced CPP and motor activity levels, and on the levels of ERK and CREB proteins in the hippocampus and cerebral cortex.Methods: 42 male rats were exposed to a CPP protocol, in which they underwent a conditioning paradigm with saline, quetiapine (40 mg/kg), morphine (10 mg/kg), morphine plus quetiapine (10, 20, or 40 mg/kg), or morphine plus memantine (7.5 mg/kg, a positive control drug) (n = 6 per group). The rats were tested for CPP and exploratory activity. Levels of ERK and CREB proteins in the hippocampus and cerebral cortex were also measured.Results: Quetiapine co-administered with morphine inhibited morphine-induced CPP [F (6, 70) = 11.67, p < .001] and morphine's effects on motor activity (p < .001). Morphine enhanced ERK phosphorylation in the hippocampus (p < .001) and cerebral cortex (p < .001), an effect inhibited by quetiapine.Conclusion: Quetiapine attenuates morphine-induced CPP and locomotion and these effects are associated with a reduction of ERK phosphorylation in the hippocampus and cerebral cortex. These results suggest that quetiapine should be further explored as a potential treatment for opioid use disorder.

The effect of antipsychotics on the cognitive performance of individuals with psychotic disorders: Network meta-analyses of randomized controlled trials

Cognitive deficits are a core aspect of psychotic disorders; however, it is not clear to which extent different pharmacological treatments could distinctly impact these outcomes. Hence, we conducted a systematic review and ten network meta-analyses of randomized controlled trials to compare the effect of antipsychotics on cognitive performance of individuals with psychotic disorders. Fifty-four trials were included in the analyses, enrolling 5866 patients. Compared to other antipsychotics, amisulpride performed better on verbal learning; quetiapine on composite score, attention and verbal learning; lurasidone on composite score; olanzapine on composite score and most cognitive domains; perphenazine on composite score, executive function, working memory, and verbal learning; risperidone on executive function and verbal learning; sertindole on processing speed; and ziprasidone on composite score, working memory, and verbal learning. Oppositely, haloperidol performed poorer on all cognitive domains, occupying the last positions in all rankings; and clozapine performed poorer on composite score, executive function, verbal learning, and visuoconstruction. We hope that these results should be taken into account when assessing and treating individuals with psychosis.

Polygenic analysis suggests the involvement of calcium signaling in executive function in schizophrenia patients

Cognitive deficits are increasingly recognized as a core dimension rather than a consequence of schizophrenia (SCZ). The previous evidence supports the hypothesis of shared genetic factors between SCZ and cognitive ability. The objective of this study was to test whether and to what extent the variation of disease-relevant neurocognitive function in a sample of SCZ patients from the previous clinical interventional studies can be explained by SCZ polygenic risk scores (PRSs) or by hypothesis-driven and biomedical PRSs. The previous studies have described associations of the SNAP25 gene with cognition in SCZ. Likewise, the enrichment of several calcium signaling-related gene sets has been reported by genome-wide association studies (GWAS) in SCZ. Hypothesis-driven PRSs were calculated on the basis of the SNAP-25 interactome and also for genes regulated by phorbol myristate acetate (PMA), an activator of the signal transduction of protein kinase C (PKC) enzymes. In a cohort of 127 SCZ patients who had completed a comprehensive neurocognitive test battery as part of the previous antipsychotic intervention studies, we investigated the association between neurocognitive dimensions and PRSs. The PRS for SCZ and SNAP-25-associated genes could not explain the variance of neurocognition in this cohort. At a p value threshold of 0.05, the PRS for PMA was able to explain 2% of the variance in executive function (p = 0.05, uncorrected). The correlation between the PRS for PMA-regulated genes and cognition can give hints for further patient-derived cellular assays. In conclusion, incorporating biological information into PRSs and other en masse genetic analyses may help to close the gap between genetic vulnerability and the biological processes underlying neuropsychiatric diseases such as SCZ.

A commentary on the efficacy of olanzapine for the treatment of schizophrenia: the past, present, and future

Olanzapine is a second-generation atypical antipsychotic with proven efficacy for the treatment of schizophrenia. Approved in 1996, olanzapine is one of the most studied antipsychotics, resulting in a considerable amount of clinical data across diverse patient populations. Despite the fact that olanzapine is associated with a known risk of metabolic side effects, including weight gain, many clinicians continue to prescribe olanzapine for the treatment of schizophrenia with the expectation of additional therapeutic antipsychotic efficacy relative to other first-line atypical antipsychotics. The goal of this narrative is to revisit the role of oral olanzapine in the management of patients with schizophrenia, including those with recently diagnosed schizophrenia ("first-episode"), those with an established schizophrenia diagnosis who experience acute exacerbations, those receiving long-term antipsychotic treatment as a maintenance intervention, and those with suboptimal response to antipsychotic treatment, including treatment resistance. Collectively, data from published literature support the favorable efficacy of olanzapine compared with other first- and second-generation antipsychotics, including lower rates of treatment discontinuation and clinically meaningful improvements in the symptoms of schizophrenia. The development of antipsychotic medications with the favorable efficacy of olanzapine, but with reduced weight gain, could address a major unmet need in the treatment of schizophrenia.

Anticholinergic discontinuation and cognitive functions in patients with schizophrenia: a pharmacist-physician collaboration in the outpatient department

INTRODUCTION

Cognitive impairment is a core feature and shows the highest impact on functional outcome in patients with schizophrenia. There have been no previous studies investigating the role of the pharmacist in a multidisciplinary team on cognitive outcomes in patients with schizophrenia.

PURPOSE

We evaluated the impact of pharmacist intervention on cognitive outcomes in patients with schizophrenia by focusing on anticholinergic discontinuation.

PATIENTS AND METHODS

A prospective, open-label, randomized, controlled study was conducted. Patients with schizophrenia were randomly assigned to either the pharmacist intervention or usual care groups. In the pharmacist intervention group, the pharmacist identified drug-related problems (DRPs) and provided a pharmacotherapy suggestion, while there was no intervention in the usual care group. The primary outcome was mean change from baseline of executive function by using Wisconsin Card Sorting Test (WCST) perseverative errors within the pharmacist intervention group at week 12.

RESULTS

A total of 30 patients completed the study (13 in the pharmacist intervention group and 17 in the usual care group). WCST perseverative errors at the end of the study within the pharmacist intervention group improved significantly from baseline (P=0.003). DRPs at week 12 were reduced by 85.19% and 9.76% in the pharmacist intervention and usual care groups, respectively. The most common intervention was the discontinuation of anticholinergics in patients without extrapyramidal side effects.

CONCLUSION

Added-on pharmacist intervention in a multidisciplinary team could help to improve cognitive functions in patients with schizophrenia by reducing DRPs and optimizing the drug therapy regimen, especially for anticholinergic discontinuation.

Comparing the effect of the subcategories of atypical antipsychotic medications on cognition in schizophrenia using a meta-analytic approach

OBJECTIVES

The aim of this study was to compare the two most commonly prescribed classes of atypical antipsychotic medications (i.e., -pines and -dones) with regard to their effects on cognition in patients with schizophrenia.

DATA SOURCES

Ovid Technologies web-based software was used to search the Medline and PsycINFO computerized databases to identify articles that met the inclusion criteria.

REVIEW METHODS

The search was limited to papers published after 1990, written in English, employing human subjects, using atypical antipsychotics, using a within-subjects design or control group of patients with schizophrenia for comparisons, using participants aged from 18-65, and employing standardized neuropsychological measures.

RESULTS

A total of 996 eligible studies were identified, and of these 19 were finally analyzed. Nine domains of cognitive functioning were assessed. The two groups of agents produced equivalent overall effects (-dones = .254 versus -pines = .202). The -pines were found to improve the domains of attention/working memory, executive functioning, fluency, nonverbal memory, processing speed, and verbal memory, each with a significant, small effect size. The -dones were found to improve attention/working memory, executive functioning, motor function, nonverbal memory, processing speed, and verbal memory, each with a significant, small effect size. Failsafe N was robust for all of the domains for the -pines, but only for the verbal memory domain for the -dones, suggesting that the significant findings for the other domains with the -dones are more tenuous.

CONCLUSION

The results indicate that the agents were largely equivalent and that there was no clear evidence that the pattern of cognitive effects differed as a result of the agent applied. The effects themselves, while statistically significant, were small, indicating that some or all of the differences may be attributable to practice effects on the instruments employed.

Associations of NEUROD2 polymorphisms and change of cognitive dysfunctions in schizophrenia and schizoaffective disorder after eight weeks of antipsychotic treatment

INTRODUCTION

NEUROD2 is a neurospecific helix-loop-helix transcription factor which has an impact on the regulation of glutamatergic and GABAergic genes. We investigated an association of NEUROD2 with neurocognitive dysfunctions in schizophrenia and schizoaffective disorder patients before and during treatment with different second-generation antipsychotics.

METHODS

Patients were genotyped for four different polymorphisms of the NEUROD2 gene ((rs9889354(A/G), rs1877032(C/T), rs12453682(C/T) and rs11078918(C/G)). Cognitive function was assessed at baseline and week 8. Results of individual neuropsychological tests were assigned to six cognitive domains (reaction time and quality; executive function; working, verbal and visual memory) and a general cognitive index.

RESULTS

167 patients were included in the study. The NEUROD2 exonic polymorphism rs11078918 showed significant associations with verbal memory and executive functions, whereas the NEUROD2 polymorphism rs12453682 was significantly associated with working and verbal memory, executive functions and with a cognitive index. Significant associations were found at baseline and after eight weeks. Moreover, significant associations between the change in neuropsychological test results during antipsychotic treatment and the NEUROD2 polymorphisms rs11078918 and rs12453682 were observed.

CONCLUSIONS

Our findings suggest that the NEUROD2 gene could play a role in the pathophysiology of neurocognitive dysfunctions as well as in the change of cognitive symptoms under antipsychotic treatment in schizophrenia and schizoaffective disorder.

Second-generation antipsychotic effect on cognition in patients with schizophrenia--a meta-analysis of randomized clinical trials

OBJECTIVE

To investigate the effect of second-generation antipsychotics on cognitive function in patients diagnosed with schizophrenia or schizoaffective disorder.

METHOD

Multiple-treatments meta-analysis model.

RESULTS

On cognitive composite score, sertindole was superior to clozapine, effect size (ES) 0.87; 95% CI: 0.12-1.63, quetiapine, ES 0.75; 95% CI: 0.00-1.49, and first-generation antipsychotics (FGAs), ES 0.89; 95% CI: 0.14-1.64. Analyses on each cognitive domain showed clozapine, ES 0.37; 95% CI: 0.00-0.74, olanzapine, ES 0.31; 95%CI: 0.02-0.59, quetiapine, ES 0.34; 95% CI: 0.03-0.64, and FGAs, ES 0.51; 95% CI: 0.18-0.83 performing poorer on verbal working memory than ziprasidone, as well as FGAs performing poorer than risperidone, ES 0.31; 95% CI: 0.04-0.58. On executive function, sertindole performed better than clozapine, ES 0.82; 95% CI: 0.06-1.58, olanzapine, ES 0.81; 95% CI: 0.07-1.55, quetiapine, ES 0.76; 95% CI: 0.02-1.51, ziprasidone, ES 0.90; 95% CI: 0.14-1.67, and FGAs, ES 0.83; 95% CI: 0.08-1.58. On processing speed, FGAs performed poorer than sertindole, ES 0.97; 95% CI: 0.02-1.91, and quetiapine, ES 0.36; 95% CI: 0.01-0.72. On long-term verbal working memory, clozapine performed poorer than olanzapine, ES 0.41; 95% CI: 0.06-0.76. On verbal fluency, FGAs performed poorer than olanzapine, ES 0.26; 95% CI: 0.01-0.50, and clozapine, ES 0.44; 95% CI: 0.06-0.81. Lastly, FGAs, ES 0.41; 95% CI: 0.04-0.78, and clozapine, ES 0.44; 95% CI: 0.05-0.83, performed poorer on visuospatial skill compared to olanzapine.

CONCLUSION

The meta-analysis was able to detect some trends in the data analyzed, but did not show any drug having a uniform positive cognitive profile.

Almost all antipsychotics result in weight gain: a meta-analysis

Introduction

Antipsychotics (AP) induce weight gain. However, reviews and meta-analyses generally are restricted to second generation antipsychotics (SGA) and do not stratify for duration of AP use. It is hypothesised that patients gain more weight if duration of AP use is longer.

Method

A meta-analysis was conducted of clinical trials of AP that reported weight change. Outcome measures were body weight change, change in BMI and clinically relevant weight change (7% weight gain or loss). Duration of AP-use was stratified as follows: ≤6 weeks, 6–16 weeks, 16–38 weeks and >38 weeks. Forest plots stratified by AP as well as by duration of use were generated and results were summarised in figures.

Results

307 articles met inclusion criteria. The majority were AP switch studies. Almost all AP showed a degree of weight gain after prolonged use, except for amisulpride, aripiprazole and ziprasidone, for which prolonged exposure resulted in negligible weight change. The level of weight gain per AP varied from discrete to severe. Contrary to expectations, switch of AP did not result in weight loss for amisulpride, aripiprazole or ziprasidone. In AP-naive patients, weight gain was much more pronounced for all AP.

Conclusion

Given prolonged exposure, virtually all AP are associated with weight gain. The rational of switching AP to achieve weight reduction may be overrated. In AP-naive patients, weight gain is more pronounced.

The influence of switching from risperidone to paliperidone on the extrapyramidal symptoms and cognitive function in elderly patients with schizophrenia: a preliminary open-label trial

OBJECTIVE

This study was to evaluate the effects on clinical symptoms and cognitive function of switching the treatment of elderly patients with schizophrenia from risperidone to paliperidone (PAL).

METHODS

This study was a 12-weeks, preliminary open-label trial. The subjects were 17 inpatients. Their extrapyramidal symptoms (EPS) were assessed using the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS), Abnormal Involuntary Movement Scale (AIMS), and Barnes Akathisia Scale (BAS), and their cognitive function was assessed using the Brief Assessment Cognition in Schizophrenia: Japanese language version (BACS-J), and their clinical symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression-Severity of illness scale (CGI-S) at the 0 and 12 weeks.

RESULTS

The DIEPSS and BAS significantly improved after switching from risperidone to PAL. Furthermore, improvement was found on AIMS. The mean change from baseline in z-score of the digit sequencing task was significantly increased. All items on the PANSS and CGI-S were not significant; however, changes in some cognitive function were correlated with changes in EPS.

CONCLUSIONS

The results of this study suggest the possibility that switching elderly patients from risperidone to PAL may have improved pre-existing EPS, and may also have helped improve working memory.

Quetiapine versus other atypical antipsychotics for schizophrenia

BACKGROUND

In many countries, second-generation ('atypical') antipsychotic drugs have become the first-line drug treatment for people with schizophrenia. It is not clear how the effects of the various second-generation antipsychotic drugs differ.

OBJECTIVES

To evaluate the effects of quetiapine compared with other second-generation (atypical) antipsychotic drugs in the treatment of people with schizophrenia and schizophrenia-like psychoses.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group Trials Register (May 2010), inspected references of all identified studies, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing oral quetiapine with other oral forms of atypical antipsychotic medication in people with schizophrenia or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data, we calculated risk ratios (RRs) and their 95% confidence intervals (CIs) on an intention-to-treat basis based on a random-effects model. We calculated number needed to treat for an additional beneficial outcome (NNTB) where appropriate. For continuous data, we calculated mean differences (MDs), again based on a random-effects model.

MAIN RESULTS

Efficacy data tended to favour the control drugs over quetiapine (Positive and Negative Syndrome Scale (PANSS) total score vs olanzapine: 11 RCTs, n = 1486, mean quetiapine endpoint score 3.67 higher, CI 1.95 to 5.39, low quality; vs risperidone: 13 RCTs, n = 2155, mean quetiapine endpoint score 1.74 higher, CI 0.19 to 3.29, moderate quality; vs paliperidone: 1 RCT, n = 319, mean quetiapine endpoint score 6.30 higher, CI 2.77 to 9.83, moderate quality), but the clinical meaning of these data is unclear. No clear mental state differences were noted when quetiapine was compared with clozapine, aripiprazole or ziprasidone. Compared with olanzapine, quetiapine produced slightly fewer movement disorders (7 RCTs, n = 1127, RR use of antiparkinson medication 0.51, CI 0.32 to 0.81, moderate quality) and less weight gain (8 RCTs, n = 1667, RR 0.68, CI 0.51 to 0.92, moderate quality) and glucose elevation, but increased QTc prolongation (3 RCTs, n = 643, MD 4.81, CI 0.34 to 9.28). Compared with risperidone, quetiapine induced slightly fewer movement disorders (8 RCTs, n = 2163, RR use of antiparkinson medication 0.5, CI 0.36 to 0.69, moderate quality), less prolactin increase (7 RCTs, n = 1733, MD -35.25, CI -43.59 to -26.91) and some related adverse effects but greater cholesterol increase (6 RCTs, n = 1473, MD 8.57, CI 4.85 to 12.29). On the basis of limited data, compared with paliperidone, quetiapine induced fewer parkinsonian side effects (1 RCT, n = 319, RR use of antiparkinson medication 0.64, CI 0.45 to 0.91, moderate quality) and less prolactin increase (1 RCT, n = 319, MD -49.30, CI -57.80 to -40.80) and weight gain (1 RCT, n = 319, RR weight gain of 7% or more of total body weight 2.52, CI 0.5 to 12.78, moderate quality). Compared with ziprasidone, quetiapine induced slightly fewer extrapyramidal adverse effects (1 RCT, n = 522, RR use of antiparkinson medication 0.43, CI 0.2 to 0.93, moderate quality) and less prolactin increase. On the other hand, quetiapine was more sedating and led to greater weight gain (2 RCTs, n = 754, RR 2.22, CI 1.35 to 3.63, moderate quality) and cholesterol increase when compared with ziprasidone.

AUTHORS' CONCLUSIONS

Available evidence from trials suggests that most people who start quetiapine stop taking it within a few weeks (around 60%). Comparisons with amisulpride, sertindole and zotepine do not exist. Although efficacy data favour olanzapine and risperidone compared with quetiapine, the clinical meaning of these data remains unclear. Quetiapine may produce fewer parkinsonian effects than paliperidone, aripiprazole, ziprasidone, risperidone and olanzapine. Quetiapine appears to have a similar weight gain profile to risperidone, as well as clozapine and aripiprazole (although data are very limited for the latter two comparators). Quetiapine may produce greater weight gain than ziprasidone and less weight gain than olanzapine and paliperidone. Most data that have been reported within existing comparisons are of very limited value because of assumptions and biases within them. Much scope is available for further research into the effects of this widely used drug.

Quetiapine and flupentixol differentially improve anterior cingulate cortex function in schizophrenia patients: an event-related potential study

Atypical antipsychotic agents are a frequently and effectively used treatment in schizophrenia and psychotic disorders. Other than conventional antipsychotics, which mainly exert their pharmacological effect in subcortical dopaminergic systems, atypical antipsychotics additionally affect partly serotonergically innervated structures within prefrontal areas, such as the anterior cingulate cortex (ACC). However, only few controlled, randomized studies have so far investigated direct and indirect effects of atypical antipsychotics on the ACC and, up until now, no clinical investigation has exclusively addressed the specific effects of quetiapine on ACC function. The present study assessed ACC function in 18 quetiapine-medicated patients and 13 flupentixol-treated patients suffering from schizophrenia by means of the error-related negativity (ERN), a neurophysiological marker of ACC function, in a pre-post design. Between-group comparisons revealed different effects of quetiapine and flupentixol on ACC function despite similar improvement in psychopathology, cognitive performance and quality of life. Whereas atypical treatment was associated with an increase in amplitudes over time, there were prolonged ERN peak latencies in patients treated with the typical agent. Moreover, treatment effects depended on baseline prefrontal cortex function in both groups. We conclude that both flupentixol and quetiapine improve prefrontal function especially in patients with weak initial ACC function which might be due to their shared affinity for serotonin receptors in frontal brain regions. However, since this affinity is more pronounced for quetiapine, patients treated with quetiapine seemed to profit more evidently concerning their prefrontal cortex function compared to patients of the flupentixol group, who exhibited a compensatory prolongation of processes.

Comparing tolerability of olanzapine in schizophrenia and affective disorders: a meta-analysis

BACKGROUND

Olanzapine is prescribed for a number of psychiatric disorders, including schizophrenia, bipolar mania, and unipolar and bipolar depression. Olanzapine treatment is associated with tolerability issues such as metabolic adverse effects (e.g. weight gain, increase in blood glucose, triglycerides and total cholesterol levels), extrapyramidal symptoms [EPS] (e.g. parkinsonism, akathisia, tardive dyskinesia) and sedative adverse effects. Metabolic issues lead to some long-term consequences, which include cardiovascular diseases (CVD) and type 2 diabetes mellitus, and these complications cause high rates of mortality and morbidity among patients with severe mental illnesses. The expanded indications of olanzapine in psychiatry suggest a need to investigate whether there is a difference in the incidence and severity of adverse effects related to category diagnosis. Are the adverse effects expressed differently according to phenotype? Unfortunately, there are no reported studies that investigated these differences in adverse effects associated with olanzapine treatment in psychiatric patients with different phenotypes.

OBJECTIVE

The aim of the present meta-analysis is to separately examine olanzapine-induced cardiometabolic adverse effects and EPS in patients with schizophrenia and affective disorders.

DATA SOURCES

A search of computerized literature databases PsycINFO (1967-2010), PubMed (MEDLINE), EMBASE (1980-2010) and the clinicaltrials.gov website for randomized clinical trials was conducted. A manual search of reference lists of published review articles was carried out to gather further data.

STUDY SELECTION

Randomized controlled trials were included in our study if (i) they assessed olanzapine adverse effects (metabolic or extrapyramidal) in adult patients with schizophrenia or affective disorders; and (ii) they administered oral olanzapine as monotherapy during study.

DATA EXTRACTION

Two reviewers independently screened abstracts for choosing articles and one reviewer extracted relevant data on the basis of predetermined exclusion and inclusion criteria. It should be mentioned that for the affective disorders group we could only find articles related to bipolar disorder.

DATA SYNTHESIS

Thirty-three studies (4831 patients) that address olanzapine monotherapy treatment of adults with schizophrenia or bipolar disorder were included in the analysis. The primary outcomes were metabolic adverse effects (changes in weight, blood glucose, low-density lipoprotein, total cholesterol and triglyceride levels). The secondary outcomes of our study were assessing the incidence of some EPS (parkinsonism, akathisia and use of antiparkinson medication). The tolerability outcomes were calculated separately for the schizophrenia and bipolar disorder groups and were combined in a meta-analysis. Tolerability outcomes show that olanzapine contributes to weight gain and elevates blood triglycerides, glucose and total cholesterol levels in both schizophrenia and bipolar disorder patients. However, olanzapine treatment produced significantly more weight gain in schizophrenia patients than in bipolar disorder patients. In addition, increases in blood glucose, total cholesterol and triglyceride levels were higher in the schizophrenia group compared with the bipolar disorder group, even though these differences were not statistically significant. Based on our results, the incidence of parkinsonism was significantly higher in the schizophrenia group than in the bipolar disorder group. Subgroup analysis and logistic regression were used to assess the influence of treatment duration, dose, industry sponsorship, age and sex ratio on tolerability outcome.

CONCLUSIONS

Our results suggest that schizophrenia patients may be more vulnerable to olanzapine-induced weight gain. The findings may be explained by considering the fact that in addition to genetic disposition for metabolic syndrome in schizophrenia patients, they have an especially high incidence of lifestyle risk factors for CVD, such as poor diet, lack of exercise, stress and smoking. It might be that an antipsychotic induces severity of adverse effect according to the phenotype.

The influence of switching from haloperidol decanoate depot to risperidone long-acting injection on the clinical symptoms and cognitive function in schizophrenia

OBJECTIVE

This study was a comparative investigation of the effects on clinical symptoms and cognitive function of switching the treatment of schizophrenia patients from haloperidol decanoate depot to risperidone long-acting injection (RLAI) compared with a control group that continued receiving haloperidol decanoate depot.

METHODS

This study was a 24-week, non-randomized, non-double blind, open-label trial. The subjects' clinical symptoms were assessed using the Positive and Negative Syndrome Scale, and their cognitive function was assessed using the Wisconsin Card Sorting Test: Keio Version to assess executive function and the St. Marianna University School of Medicine's Computerized Memory Test to assess memory and concentration at 0 and 24 weeks.

RESULTS

The mean change from baseline in the number of categories achieved at the second stage of the Wisconsin Card Sorting Test: Keio Version was significantly greater in the RLAI group than in the control group. The mean changes from baseline in the individual St. Marianna University School of Medicine's Computerized Memory Tests were significantly greater in the RLAI group than in the control group. The RLAI group needed a lower dosage of biperiden compared with the control group, even though they had similar risperidone-equivalent daily dosages.

CONCLUSION

The results of this study suggest the possibility that switching from haloperidol decanoate depot to RLAI may improve cognitive function including memory, executive function, motor processing function, and attention.

The influence of switching from oral risperidone to risperidone long-acting injection on the clinical symptoms and cognitive function in schizophrenia

OBJECTIVE

This study was a comparative investigation of the effects on clinical symptoms and cognitive function of switching schizophrenia patients from oral risperidone to risperidone long-acting injection (RLAI) compared with a control group that continued receiving oral risperidone.

METHODS

The subjects were 21 patients who had been diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Their clinical symptoms were assessed using the positive and negative syndrome scale (PANSS), and their cognitive function was assessed using the Wisconsin Card Sorting Test: Keio Version (KWCST) to assess executive function, and the St Marianna University School of Medicine's Computerized Memory Test (STM-COMET) to assess memory and concentration.

RESULTS

No significant differences in clinical symptom improvement efficacy were seen between the group that was switched to RLAI and the control group. No significant differences were seen between the two groups in the mean change from baseline in any of the KWCST tests. The mean changes from baseline on the STM-COMET memory scanning test and memory filtering test were significantly greater in the group that switched to RLAI than in the control group. Furthermore, patients with RLAI needed less biperiden, even though they had similar risperidone-equivalent daily dosages as the group with oral risperidone.

CONCLUSION

The results of this study suggested that switching from oral risperidone to RLAI may affect motor processing function and attention improvement efficacy by allowing the dosage of anti-Parkinson's medication to be reduced.

Quetiapine and Buspirone Both Elevate Cortical Levels of Noradrenaline and Dopamine In vivo, but Do Not have Synergistic Effects

Decreased cognitive ability is a significant problem in schizophrenia, and it has been proposed that augmentation of antipsychotics with 5HT(1A) receptor agonists may improve cognitive performance. Clinical studies have been mixed but there have been no studies specifically examining the effects of combining the atypical antipsychotic quetiapine with the 5HT(1A) receptor partial agonist, buspirone on monoamine release. This is of interest given previous evidence that monoamine release can alter cognition in schizophrenia. In the present study we measured in vivo levels of monoamines in the frontal cortex of Sprague Dawley rats and examined if buspirone (2.5 mg/kg i.p.), altered monoamine release both when given alone and when combined with quetiapine (10 mg/kg i.p.). We found that serotonin levels were not altered by either drug, either alone or in combination. In contrast, both buspirone and quetiapine monotherapy significantly increased release of noradrenaline (112 and 160% respectively) and dopamine (169 and 191% respectively) compared to controls. However, there were no additional increases in in vivo monoamine release when the combination of these drugs were given. One possible explanation for these negative findings could be that the intrinsic 5HT(1A) agonist activity of quetiapine on its own is of such significance that it is not further enhanced by buspirone. These findings do not support clinical studies combining buspirone and quetiapine, if these were to be used on the basis of enhanced monoamine neurotransmission. These findings may also have implications for the atypical antipsychotic drugs in development which combine dopamine D(2) antagonism with 5HT(1A) partial agonism.

Effects of quetiapine and sertindole on subchronic ketamine-induced deficits in attentional set-shifting in rats

RATIONALE

Prefrontal cortical dysfunctions, including an impaired ability to shift perceptual attentional set, are core features of schizophrenia. Nevertheless, the effectiveness of second-generation antipsychotic drugs in treating specific prefrontal dysfunctions remains equivocal.

OBJECTIVES

To model schizophrenia-like cognitive inflexibility in rats, we evaluated the effects of repeated administration of ketamine, the noncompetitive antagonist of the N-methyl-D: -aspartate receptor, after a washout period of 14 days in the attentional set-shifting task (ASST). Next, we investigated whether the atypical antipsychotics quetiapine and sertindole would alleviate the ketamine-induced set-shifting impairment.

METHODS

Ketamine (30 mg/kg) was administered intraperitoneally to rats once daily for 5 or 10 consecutive days to assess its efficacy in producing cognitive impairment. The ASST was performed 14 days following the final drug administration. Quetiapine (0.63, 1.25 or 2.5 mg/kg) or sertindole (2.5 mg/kg) was administered per os 120 min before testing.

RESULTS

The results of the present study demonstrate that ketamine treatment for 10 but not 5 days significantly and specifically impaired rats' performance in the extra-dimensional shift (EDs) stage of the ASST. This cognitive inflexibility was reversed by acute administration of sertindole or quetiapine. Quetiapine also promoted set-shifting in cognitively unimpaired control animals.

CONCLUSION

The data presented here show that subchronic administration of ketamine induces cognitive inflexibility after a washout period. This cognitive deficit likely reflects clinically relevant aspects of cognitive dysfunction encountered in schizophrenic patients. The beneficial effects of quetiapine on set-shifting may have therapeutic implications for the treatment of schizophrenia and other disorders associated with frontal-dependent cognitive impairments.

Neurocognitive effectiveness of quetiapine, olanzapine, risperidone, and ziprasidone: a pragmatic, randomized trial

PURPOSE

Cognitive effects of second generation antipsychotics (SGAs) are indicated in efficacy studies but the generalizability of the results may be limited by rigid designs and selected samples. The aim of this naturalistic, industry-independent study is to investigate whether differential neurocognitive effectiveness can be found among olanzapine, quetiapine, risperidone, and ziprasidone in a clinically relevant sample with psychosis.

SUBJECTS AND METHODS

Adult patients acutely admitted to an emergency ward for psychosis were randomized to risperidone, olanzapine, quetiapine or ziprasidone and followed for up to 2 years. Participants were assessed repeatedly using the Positive and Negative Syndrome Scale and a repeatable neurocognitive test battery.

RESULTS

A total of 226 patients were included and 171 patients underwent neurocognitive assessments. The sample had a global cognitive performance score at baseline about one standard deviation below that of the general population. The ziprasidone group had the fastest increase in global functioning which was significantly superior to that of the olanzapine group for the entire follow-up period. Before 90 days, the quetiapine group had the fastest increase which was statistically superior to the olanzapine group.

DISCUSSION

Ziprasidone and quetiapine demonstrated superiority to olanzapine in increasing global neurocognitive performance in this naturalistic sample.

Effects of atypical antipsychotics on neurocognition in euthymic bipolar patients

BACKGROUND

Different factors may influence cognitive functioning in bipolar disorder such as the effect of subsyndromal symptoms, the history of psychotic symptomatology or substance abuse, negative symptomatology, chronicity, sleep disturbances, and hormonal factors. The effect of pharmacologic treatment on cognition is still uncertain because of an insufficient number of studies examining this issue.

OBJECTIVE

The aims of this study were to compare neuropsychologic performance of treated bipolar patients with that of controls, including unmedicated patients and healthy subjects, as well as to evaluate possible neurocognitive differences among 3 different atypical antipsychotics.

RESEARCH DESIGN AND METHODS

A total of 119 subjects were included in the study. Of 79 Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition euthymic bipolar patients, 68 were treated with one atypical antipsychotic, quetiapine (n = 12), olanzapine (n = 26), or risperidone (n = 30). Sixteen patients were drug-free. The 4 groups were compared with a sample of drug-naïve patients and a healthy control group (n = 35) on several clinical and neuropsychologic variables, especially on the domains of attention, verbal memory, and executive functions. Euthymia was defined by a score of 6 or less at the Young Mania Rating Scale and a score of 8 or less at the Hamilton Depression Rating Scale for at least 6 months.

RESULTS

The 5 groups did not differ in age, years of education, sex distribution, or estimated premorbid IQ. The 4 patients groups did not differ in chronicity, age of onset, total number of episodes, and number of hospitalizations. No differences were found regarding antipsychotic dosages between the groups. Bipolar patients performed poorly on most neuropsychologic measures as compared with healthy controls. After controlling for Hamilton Depression Rating Scale symptoms, no significant change in the results was observed. Because many patients with antipsychotic treatment had a history of psychotic symptoms, we performed multivariate analysis of covariance controlling for this variable. Bipolar patients taking 1 of the 3 antipsychotics presented with dose-independent significant deficits in most cognitive tasks compared with healthy controls. After several head-to-head group comparisons, the patients receiving quetiapine showed a better performance in learning task, short-term memory, and recognition task assessed with the California Verbal Learning Test and verbal fluency (P < .05).

CONCLUSIONS

Our results confirm the findings of previous studies of cognitive deficits in bipolar disorder. Untreated euthymic patients showed better cognitive performance than did patients on atypical antipsychotics. Some iatrogenic-pharmacologic effect, therefore, cannot be excluded, but quetiapine seemed to be less associated with impairment in measures of verbal memory than olanzapine or risperidone. We suggest to use drugs in bipolar disorder with a lower risk of cognitive adverse effects. However, randomized controlled trials are urgently needed to give a definite answer to this critical problem.

An unblinded comparison of the clinical and cognitive effects of switching from first-generation antipsychotics to aripiprazole, perospirone or olanzapine in patients with chronic schizophrenia

The objective of this study, the effect of aripiprazole on clinical symptoms and cognitive function in patients with chronic schizophrenia was compared to that of perospirone and olanzapine. The subjects were 31 patients, they were diagnosed with schizophrenia on the basis of the criteria of the DSM-IV. Clinical symptoms were assessed using Brief Psychiatric Rating Scale (BPRS), and cognitive function was assessed using the Wisconsin Card Sorting Test (Keio Version: KWCST) and the St. Marianna University School of Medicine's Computerized Memory Test (STM-COMET) as executive function and memory/attention function tests at baseline and 8 weeks after switching. As a result, comparison of the BPRS mean total score revealed no significant difference between aripiprazole and the other medications. Aripiprazole resulted in significant changes in the number of categories achieved (CA) and difficulty maintaining set (DMS) compared to olanzapine at the second level of the KWCST. Comparison thus revealed no difference in clinical effect between aripiprazole and the other medications, but might suggest possible differences between aripiprazole and olanzapine in the profiles of the improvement effects on executive function, memory, and attention function.

Serotonin 6 receptor gene is associated with methamphetamine-induced psychosis in a Japanese population

BACKGROUND

Altered serotonergic neural transmission is hypothesized to be a susceptibility factor for psychotic disorders such as schizophrenia. The serotonin 6 (5-HT6) receptor is therapeutically targeted by several second generation antipsychotics, such as clozapine and olanzapine, and d-amphetamine-induced hyperactivity in rats is corrected with the use of a selective 5-HT6 receptor antagonist. In addition, the disrupted prepulse inhibition induced by d-amphetamine or phencyclidine was restored by 5-HT6 receptor antagonist in an animal study using rats. These animal models were considered to reflect the positive symptoms of schizophrenia, and the above evidence suggests that altered 5-HT6 receptors are involved in the pathophysiology of psychotic disorders. The symptoms of methamphetamine (METH)-induced psychosis are similar to those of paranoid type schizophrenia. Therefore, we conducted an analysis of the association of the 5-HT6 gene (HTR6) with METH-induced psychosis.

METHOD

Using five tagging SNPs (rs6693503, rs1805054, rs4912138, rs3790757 and rs9659997), we conducted a genetic association analysis of case-control samples (197 METH-induced psychosis patients and 337 controls) in the Japanese population. The age and sex of the control subjects did not differ from those of the methamphetamine dependence patients.

RESULTS

rs6693503 was associated with METH-induced psychosis patients in the allele/genotype-wise analysis. Moreover, this association remained significant after Bonferroni correction. In the haplotype-wise analysis, we detected an association between two markers (rs6693503 and rs1805054) and three markers (rs6693503, rs1805054 and rs4912138) in HTR6 and METH-induced psychosis patients, respectively.

CONCLUSION

HTR6 may play an important role in the pathophysiology of METH-induced psychosis in the Japanese population.

Cholinergic contributions to the cognitive symptoms of schizophrenia and the viability of cholinergic treatments

Effective treatment of the cognitive symptoms of schizophrenia has remained an elusive goal. Despite the intense focus on treatments acting at or via cholinergic mechanisms, little remains known about the dynamic cholinergic abnormalities that contribute to the manifestation of the cognitive symptoms in patients. Evidence from basic neuroscientific and psychopharmacological investigations assists in proposing detailed cholinergic mechanisms and treatment targets for enhancement of attentional performance. Dynamic, cognitive performance-dependent abnormalities in cholinergic activity have been observed in animal models of the disorder and serve to further refine such proposals. Finally, the potential usefulness of individual groups of cholinergic drugs and important issues concerning the interactions between pro-cholinergic and antipsychotic treatments are addressed. The limited evidence available from patient studies and animal models indicates pressing research needs in order to guide the development of cholinergic treatments of the cognitive symptoms of schizophrenia.

Comparison of metabolic and prolactin variables from a six-month randomised trial of olanzapine and quetiapine in schizophrenia

Schizophrenia patients have a potential increased risk of metabolic dysregulation during antipsychotic treatments. Our objective was to compare changes in prolactin and metabolic variables (glucose, lipids and weight) as a post-hoc analysis from a six-month, randomised, controlled study of olanzapine (OLZ, n = 171; 10-20 mg/day) or quetiapine (QUE, n = 175; 300-700 mg/day). No statistically significant treatment group differences for baseline to endpoint mean changes in body mass index (P = 0.209) or weight (P = 0.250) were observed. There was a greater incidence of clinically significant weight gain (defined as > or =7% increase from baseline) in OLZ (19.2%) compared to QUE (13.2%)-treated patients (P = 0.181). No statistically significant treatment group differences for lipids and glucose variables, either as mean change from baseline to endpoint or treatment-emergent (TE) categorical changes were found (P > or = 0.05). Incidence rates for TE diabetes were similar between treatment groups 2.5% (n = 4) in the OLZ-treatment group and 1.3% (n = 2) in the QUE-treatment group (P = 0.685). Hyperprolactinaemia was present at baseline in many patients (OLZ 32.9%; QUE 31.4%), but after 2 weeks of treatment prolactin values had reverted to normal for nearly all patients (OLZ 100%; QUE 99.4%). There were no significant treatment differences in any variable between cohorts.

The switch from conventional to atypical antipsychotic treatment should not be based exclusively on the presence of cognitive deficits. A pilot study in individuals with schizophrenia

BACKGROUND

Atypical antipsychotics provide better control of the negative and affective symptoms of schizophrenia when compared with conventional neuroleptics; nevertheless, their heightened ability to improve cognitive dysfunction remains a matter of debate. This study aimed to examine the changes in cognition associated with long-term antipsychotic treatment and to evaluate the effect of the type of antipsychotic (conventional versus novel antipsychotic drugs) on cognitive performance over time.

METHODS

In this naturalistic study, we used a comprehensive neuropsychological battery of tests to assess a sample of schizophrenia patients taking either conventional (n = 13) or novel antipsychotics (n = 26) at baseline and at two years after.

RESULTS

Continuous antipsychotic treatment regardless of class was associated with improvement on verbal fluency, executive functions, and visual and verbal memory. Patients taking atypical antipsychotics did not show greater cognitive enhancement over two years than patients taking conventional antipsychotics.

CONCLUSIONS

Although long-term antipsychotic treatment slightly improved cognitive function, the switch from conventional to atypical antipsychotic treatment should not be based exclusively on the presence of these cognitive deficits.

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

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

Olanzapine versus other atypical antipsychotics for schizophrenia

BACKGROUND

In many countries of the industrialised world second generation ("atypical") antipsychotics have become the first line drug treatment for people with schizophrenia. The question as to whether, and if so how much, the effects of the various second generation antipsychotics differ is a matter of debate. In this review we examined how the efficacy and tolerability of olanzapine differs from that of other second generation antipsychotics.

OBJECTIVES

To evaluate the effects of olanzapine compared to other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychosis.

SEARCH STRATEGY

1. Electronic searching We searched the Cochrane Schizophrenia Group Trials Register (April 2007) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO.2. Reference searching We inspected the reference of all identified studies for more trials.3. Personal contact We contacted the first author of each included study for missing information.4. Drug companies We contacted the manufacturers of all atypical antipsychotics included for additional data.

SELECTION CRITERIA

We included all randomised trials that used at least single-blind (rater-blind) design, comparing oral olanzapine with oral forms of amisulpride, aripiprazole, clozapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia-like psychosis.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (WMD) again based on a random effects model.

MAIN RESULTS

The review currently includes 50 studies and 9476 participants which provided data for six comparisons (olanzapine compared to amisulpride, aripiprazole, clozapine, quetiapine, risperidone or ziprasidone). The overall attrition from the included studies was considerable (49.2%) leaving the interpretation of results problematic.Olanzapine improved the general mental state (PANSS total score) more than aripiprazole (2 RCTs, n=794, WMD -4.96 CI -8.06 to -1.85), quetiapine (10 RCTs, n=1449, WMD -3.66 CI -5.39 to -1.93), risperidone (15 RCTs, n=2390, WMD -1.94 CI -3.31 to -0.58) and ziprasidone (4 RCTs, n=1291, WMD -8.32 CI -10.99 to -5.64), but not more than amisulpride or clozapine. This somewhat better efficacy was confirmed by fewer participants in the olanzapine groups leaving the studies early due to inefficacy of treatment compared to quetiapine (8 RCTs, n=1563, RR 0.56 CI 0.44 to 0.70, NNT 11 CI 6 to 50), risperidone (14 RCTs, n=2744, RR 0.78 CI 0.62 to 0.98, NNT 50 CI 17 to 100) and ziprasidone (5 RCTs, n=1937, RR 0.64 CI 0.51 to 0.79, NNT 17, CI 11 to 33).Fewer participants in the olanzapine group than in the quetiapine (2 RCTs, n=876, RR 0.56 CI 0.41 to 0.77, NNT 11 CI 7 to 25) and ziprasidone (2 RCTs, n=766, RR 0.65 CI 0.45 to 0.93, NNT 17 CI 9 to 100) treatment groups, but not in the clozapine group (1 RCT, n=980, RR 1.28 CI 1.02 to 1.61, NNH not estimable), had to be re-hospitalised in the trials.Except for clozapine, all comparators induced less weight gain than olanzapine (olanzapine compared to amisulpride: 3 RCTs, n=671, WMD 2.11kg CI 1.29kg to 2.94kg; aripiprazole: 1 RCT, n=90, WMD 5.60kg CI 2.15kg to 9.05kg; quetiapine: 7 RCTs, n=1173, WMD 2.68kg CI 1.10kg to 4.26kg; risperidone: 13 RCTs, n=2116, WMD 2.61kg CI 1.48kg to 3.74kg; ziprasidone: 5 RCTs, n=1659, WMD 3.82kg CI 2.96kg to 4.69kg). Associated problems such as glucose and cholesterol increase were usually also more frequent in the olanzapine group.Other differences in adverse effects were less well documented. Nevertheless, olanzapine may be associated with slightly more extrapyramidal side effects than quetiapine (use of antiparkinson medication (6 RCTs, n=1090, RR 2.05 CI 1.26 to 3.32, NNH 25 CI 14 to 100), but less than risperidone (use of antiparkinson medication 13 RCTs, n=2599, RR 0.78 CI 0.65 to 0.95, NNH 17 CI 9 to 100) and ziprasidone (use of antiparkinson medication 4 RCTs, n=1732, RR 0.70 CI 0.50 to 0.97, NNH not estimable). It may also increase prolactin somewhat more than aripiprazole, clozapine and quetiapine, but clearly less so than risperidone (6 RCTs, n=1291, WMD -22.84 CI -27.98 to -17.69).

AUTHORS' CONCLUSIONS

Olanzapine may be a somewhat more efficacious drug than some other second generation antipsychotic drugs. This small superiority in efficacy needs to be weighed against a larger weight gain and associated metabolic problems than most other second generation antipsychotic drugs, except clozapine. These conclusions are tentative due to the large number of people leaving the studies early which possibly limits the validity of the findings. Further large, well-designed trials are necessary to establish the relative effects of different second generation antipsychotic drugs.

Neurocognition and its influencing factors in the treatment of schizophrenia-effects of aripiprazole, olanzapine, quetiapine and risperidone

BACKGROUND

To examine influencing variables of neurocognition in patients with schizophrenia and to predict cognition during antipsychotic treatment.

METHODS

Data were obtained from patients with an acute episode of schizophrenia participating in two double-blind and one open label trial comparing the effects of different atypical antipsychotics on cognition. In total, 129 patients were enrolled in this analysis. Cognitive function was assessed at admission, week 4 and 8. Efficacy and tolerability were assessed weekly using the Positive and Negative Syndrome Scale (PANSS) and the Simpson Angus Sale (SAS). Patients were treated with aripirazole, olanzapine, quetiapine and risperidone. Regression analysis including mixed effect models was performed.

RESULTS

A significant improvement in all cognitive domains was observed from baseline to week 8. Regarding the antipsychotic treatment applied quetiapine seemed to achieve the most favourable cognitive improvement. Negative and depressive symptoms, the patient's age and the concomitant and antipsychotic treatment applied were observed to significantly influence and predict neurocognition.

CONCLUSION

The results may indicate that schizophrenia is a static disorder with trait and state dependent cognitive components especially in the memory domains. The influence of negative and depressive symptoms should be considered in daily clinical routine.

Quetiapine versus other atypical antipsychotics for schizophrenia

BACKGROUND

In many countries of the industrialised world second generation ('atypical') antipsychotic drugs have become the first line drug treatment for people with schizophrenia. It is not clear how the effects of the various second generation antipsychotic drugs differ.

OBJECTIVES

To evaluate the effects of quetiapine compared with other second generation antipsychotic drugs for people with schizophrenia and schizophrenia-like psychosis.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group Trials Register (April 2007), inspected references of all identified studies, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information.

SELECTION CRITERIA

We included all randomised control trials comparing oral quetiapine with oral forms of amisulpride, aripiprazole, clozapine, olanzapine, risperidone, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia-like psychosis.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (WMD) again based on a random-effects model.

MAIN RESULTS

The review currently includes 21 randomised control trials (RCTs) with 4101 participants. These trials provided data on four comparisons - quetiapine versus clozapine, olanzapine, risperidone or ziprasidone.A major limitation to all findings is the high number of participants leaving studies prematurely (57.6%) and the substantial risk of biases in studies. Efficacy data favoured olanzapine and risperidone compared with quetiapine (PANSS total score versus olanzapine:10 RCTs, n=1449, WMD 3.66 CI 1.93 to 5.39; versus risperidone: 9 RCTs, n=1953, WMD 3.09 CI 1.01 to 5.16), but clinical meaning is unclear. There were no clear mental state differences when quetiapine was compared with clozapine or ziprasidone.Compared with olanzapine, quetiapine produced slightly fewer movement disorders (6 RCTs, n=1090, RR use of antiparkinson medication 0.49 CI 0.3 to 0.79, NNH 25 CI 14 to 100) and less weight gain (7 RCTs, n=1173, WMD -2.81 CI -4.38 to -1.24) and glucose elevation, but more QTc prolongation (3 RCTs, n=643, WMD 4.81 CI 0.34 to 9.28). Compared with risperidone, quetiapine induced slightly fewer movement disorders (6 RCTs, n=1715, RR use of antiparkinson medication 0.5 CI 0.3 to 0.86, NNH 20 CI 10 to 100), less prolactin increase (6 RCTs, n=1731, WMD -35.28 CI -44.36 to -26.19) and some related adverse effects, but more cholesterol increase (5 RCTs, n=1433, WMD 8.61 CI 4.66 to 12.56). Compared with ziprasidone, quetiapine induced slightly fewer extrapyramidal adverse effects (1 RCT, n=522, RR use of antiparkinson medication 0.43 CI 0.2 to 0.93, NNH not estimable) and prolactin increase. On the other hand quetiapine was more sedating and led to more weight gain (2 RCTs, n=754, RR 2.22 CI 1.35 to 3.63, NNH 13 CI 8 to 33) and cholesterol increase than ziprasidone.

AUTHORS' CONCLUSIONS

Best available evidence from trials suggests that most people who start quetiapine stop taking it within a few weeks. Comparisons with amisulpride, aripiprazole, sertindole and zotepine do not exist. Most data that has been reported within existing comparisons are of very limited value because of assumptions and biases within them. There is much scope for further research into the effects of this widely used drug.

Cognitive effects of second-generation antipsychotics: current insights into neurochemical mechanisms

Historically, pharmacotherapy for schizophrenia was mainly focused on finding drugs to treat psychotic symptoms only, without addressing other crucial domains of the disorder such as cognitive impairments. As a result, these domains have remained undertreated. In this review, we discuss recent preclinical research efforts, including investigation of synaptic mechanisms as well as intracellular signalling pathways and mechanisms involved in neuroplasticity and cell resilience, that may represent new mechanisms participating in the pathogenesis of schizophrenia, particularly at the level of the prefrontal cortex and hippocampus, and that might lead to the development of drugs that can counteract, at least partially, the cognitive impairments typical of schizophrenia.

Resource utilization and costs of schizophrenia patients treated with olanzapine versus quetiapine in a Medicaid population

OBJECTIVE

Compare annual health-care costs and resource utilization associated with olanzapine versus quetiapine for treating schizophrenia in a Medicaid population.

METHODS

Adult schizophrenia patients were selected from deidentified Pennsylvania Medicaid claims database (1999–2003). Included patients were continuously enrolled and initiated with olanzapine or quetiapine monotherapy after a 90-day washout period. Treatment costs were calculated for 1-year post-therapy initiation and inflation adjusted to year 2003. To control for selection bias, olanzapine and quetiapine patients were 1:1 matched using an optimal matching algorithm on propensity score, which was generated using logistic regression controlling for demographics, prior drug therapy, utilization, and costs. Treatment costs for the matched cohorts were compared directly, as well as using a difference-in-difference analysis.

RESULTS

A total of 6929 patients treated with olanzapine and 2321 with quetiapine met inclusion criteria. Quetiapine patients appeared more severe at baseline. After propensity score matching, 2321 patient pairs had similar baseline characteristics, including total costs. Compared with matched quetiapine patients, for the 1-year postindex period, olanzapine patients had similar drug costs ($6131 vs. $6014, P = 0.326), lower medical costs ($9897 vs. $11,218, P = 0.0128), and lower total health-care costs ($16,028 vs. $17,232, P = 0.0279). Lower psychiatric hospitalization costs account for most of the total cost difference. Difference-in-difference regression analysis confirmed olanzapine's economic advantage. Further adjusting for baseline variations, the total cost advantage of olanzapine patients was $962 (P = 0.032), and was mostly because of reduced psychiatric hospitalization costs of $992 (P = 0.004).

CONCLUSION

Schizophrenia patients treated with olanzapine had lower total costs than quetiapine patients, mostly attributable to reductions in psychiatric hospitalization costs.

Associations of SNAP-25 polymorphisms with cognitive dysfunctions in Caucasian patients with schizophrenia during a brief trail of treatment with atypical antipsychotics

The synaptosomal-associated protein of 25 kDa (SNAP-25) is part of the soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment receptor (SNARE), which mediates synaptic neurotransmission. In earlier studies a possible involvement of this protein in schizophrenia has been shown. As neurocognitive impairment is a core feature in the pathology of schizophrenia and considered to be a putative endophenotype according to genetic studies we investigated the influences of different SNAP-25 polymorphisms on neuropsychological test results before and during treatment with atypical antipsychotics. A total of 104 schizophrenic patients treated with atypical antipsychotics were genotyped for three different polymorphisms of the SNAP-25 gene (MnlI, TaiI and DdeI in the 3'-UTR). Cognitive function was assessed at baseline, week 4 or 6 and week 8 or 12. Results of individual neuropsychological tests were assigned to six cognitive domains (reaction time and quality; executive function; working, verbal and visual memory) and a general cognitive index. The MnlI and TaiI polymorphisms showed no associations to deficits on neuropsychological test results. In contrast, we observed a significant relation between the DdeI polymorphism of the SNAP-25 gene and cognitive dysfunctions. Homozygote T/T allele carriers of the DdeI polymorphism showed significant better neuropsychological test results in cognitive domains verbal memory and executive functions than those with the combined T/C and C/C genotypes (P < 0.01) at all three time points, but no differences in response to treatment with atypical antipsychotics. Additionally, TT carriers exhibited significantly better results in a general cognitive index (P < 0.05). As we observed an association between the DdeI polymorphism of the SNAP-25 gene and cognitive dysfunctions of schizophrenic patients our finding suggests that the SNAP-25 gene could play a role in the pathophysiology of neurocognitive dysfunctions in schizophrenia but is not predictive for treatment response with atypical antipsychotics.

Quetiapine in the treatment of schizophrenia and related disorders

Quetiapine was developed in 1985 by scientists at AstraZeneca (formerly Zeneca) Pharmaceuticals. It received official US Food and Drug Administration approval in September 1997 and approval in Germany in 2000. Since then, quetiapine has been used in the treatment of severe mental illness in approximately 70 countries including Canada, most Western European countries, and Japan. Quetiapine is a dibenzothiazepine derivative with a relatively broad receptor binding profile. It has major affinity to cerebral serotonergic (5HT(2A)), histaminergic (H1), and dopaminergic D(1) and D(2) receptors, moderate affinity to alpha(1)- und alpha(2)-adrenergic receptors, and minor affinity to muscarinergic M1 receptors; it demonstrates a substantial selectivity for the limbic system. This receptor occupancy profile with relatively higher affinity for the 5HT(2A) receptor compared with the D(2) receptor is in part responsible for the antipsychotic characteristics and low incidence of extrapyramidal side-effects of quetiapine. The efficacy of quetiapine in reducing positive and negative symptoms of schizophrenia has been proven in several clinical trials with placebo-controlled comparators. Quetiapine has also demonstrated robust efficacy for treatment of cognitive, anxious-depressive, and aggressive symptoms in schizophrenia. Long-term trials show sustained tolerability for a broad spectrum of symptoms. Quetiapine has also proven efficacy and tolerability in the treatment of moderate to severe manic episodes, and in the treatment of juveniles with oppositional-defiant or conduct disorders, and in the geriatric dementia population. Recent data indicate that quetiapine may also be effective in the treatment of bipolar depressive symptoms without increasing the risk of triggering manic episodes, and in borderline personality disorder. In comparison with other antipsychotics, quetiapine has a favorable side-effect profile. In clinical trials only small insignificant prolongations of the QT interval were observed. Weight-gain liabilities and new-onset metabolic side-effects occupy a middle-ground among newer antipsychotics. As a result of its good efficacy and tolerability profile quetiapine has become well established in the treatment of schizophrenia and manic episodes.