Risperidone versus haloperidol in long-term hospitalized chronic patients in a double blind randomized trial: a post hoc analysis

Risperidone plasma level, and its correlation with CYP2D6 gene polymorphism, clinical response and side effects in chronic schizophrenia patients

BACKGROUND

To explore the influence of CYP2D6 genetic polymorphism on risperidone metabolism, thereby affecting risperidone's effects and safeties in patients with chronic schizophrenia.

METHODS

Sixty-nine subjects with chronic schizophrenia treated with risperidone were recruited. CYP2D6 genotypes was determined using targeted sequencing and translated into phenotype using activity system. Risperidone plasma concentrations were measured using HPLC. Positive and Negative Symptom Scale (PANSS) and Brief Psychiatric Rating Scale (BPRS) were used to evaluate the existence and severity of psychiatric symptoms, Barnes Akathisia Scale (BAS) and Extrapyramidal Symptom Rating Scale (ESRS) for neurological side effects. Metabolic and endocrine status assess were also included.

RESULTS

The plasma drug concentrations varied hugely among individuals. Intermediate metabolizer (IM) group had higher plasma levels of RIP and dose corrected RIP concentration, RIP/9-OH-RIP ratio and C/D ratio than normal metabolizer (NM) group (p < 0.01). There was no statistic difference between responders and non-responders in dose-adjusted plasma concentrations and ratios of RIP/9-OH-RIP and C/D. The occurrence of EPS was related to active moiety levels in 4th week (p < 0.05). The prolactin (PRL) levels in two follow-ups were both significantly higher than baseline (p < 0.01). PRL change from baseline to week 4 and week 8 were both positively associated with active moiety concentration detected in week 4 (p < 0.05).

CONCLUSIONS

The risperidone plasma levels have great inter- and intraindividual variations, and are associated with the CYP2D6 phenotypes, as well as the changes in serum prolactin in patients diagnosed with chronic schizophrenia.

Risperidone versus placebo for schizophrenia

BACKGROUND

Risperidone is the first new-generation antipsychotic drug made available in the market in its generic form.

OBJECTIVES

To determine the clinical effects, safety and cost-effectiveness of risperidone compared with placebo for treating schizophrenia.

SEARCH METHODS

On 19th October 2015, we searched the Cochrane Schizophrenia Group Trials Register, which is based on regular searches of CINAHL, BIOSIS, AMED, EMBASE, PubMed, MEDLINE, PsycINFO, and registries of clinical trials. We checked the references of all included studies and contacted industry and authors of included studies for relevant studies and data.

SELECTION CRITERIA

Randomised clinical trials (RCTs) comparing oral risperidone with placebo treatments for people with schizophrenia and/or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies, assessed the risk of bias of included studies and extracted data. For dichotomous data, we calculated the risk ratio (RR), and the 95% confidence interval (CI) on an intention-to-treat basis. For continuous data, we calculated mean differences (MD) and the 95% CI. We created a 'Summary of findings table' using GRADE (Grading of Recommendations Assessment, Development and Evaluation).

MAIN RESULTS

The review includes 15 studies (N = 2428). Risk of selection bias is unclear in most of the studies, especially concerning allocation concealment. Other areas of risk such as missing data and selective reporting also caused some concern, although not affected on the direction of effect of our primary outcome, as demonstrated by sensitivity analysis. Many of the included trials have industry sponsorship of involvement. Nonetheless, generally people in the risperidone group are more likely to achieve a significant clinical improvement in mental state (6 RCTs, N = 864, RR 0.64, CI 0.52 to 0.78, very low-quality evidence). The effect withstood, even when three studies with >50% attrition rate were removed from the analysis (3 RCTs, N = 589, RR 0.77, CI 0.67 to 0.88). Participants receiving placebo were less likely to have a clinically significant improvement on Clinical Global Impression scale (CGI) than those receiving risperidone (4 RCTs, N = 594, RR 0.69, CI 0.57 to 0.83, very low-quality evidence). Overall, the risperidone group was 31% less likely to leave early compared to placebo group (12 RCTs, N = 2261, RR 0.69, 95% CI 0.62 to 0.78, low-quality evidence), but Incidence of significant extrapyramidal side effect was more likely to occur in the risperidone group (7 RCTs, N = 1511, RR 1.56, 95% CI 1.13 to 2.15, very low-quality evidence).When risperidone and placebo were augmented with clozapine, there is no significant differences between groups for clinical response as defined by a less than 20% reduction in PANSS/BPRS scores (2 RCTs, N = 98, RR 1.15, 95% CI 0.93 to 1.42, low-quality evidence) and attrition (leaving the study early for any reason) (3 RCTs, N = 167, RR 1.13, 95% CI 0.53 to 2.42, low quality evidence). One study measured clinically significant responses using the CGI, no effect was evident (1 RCT, N = 68, RR 1.12 95% CI 0.87 to 1.44, low quality evidence). No data were available for extrapyramidal adverse effects.

AUTHORS' CONCLUSIONS

Based on low quality evidence, risperidone appears to be benefitial in improving mental state compared with placebo, but it also causes more adverse events. Eight out of the 15 included trials were funded by pharmaceutical companies. The currently available evidence isvery low to low quality.

Recommendations to improve the positive and negative syndrome scale (PANSS) based on item response theory

The adequacy of the Positive and Negative Syndrome Scale (PANSS) items in measuring symptom severity in schizophrenia was examined using Item Response Theory (IRT). Baseline PANSS assessments were analyzed from two multi-center clinical trials of antipsychotic medication in chronic schizophrenia (n=1872). Generally, the results showed that the PANSS (a) item ratings discriminated symptom severity best for the negative symptoms; (b) has an excess of "Severe" and "Extremely severe" rating options; and (c) assessments are more reliable at medium than very low or high levels of symptom severity. Analysis also showed that the detection of statistically and non-statistically significant differences in treatment were highly similar for the original and IRT-modified PANSS. In clinical trials of chronic schizophrenia, the PANSS appears to require the following modifications: fewer rating options, adjustment of 'Lack of judgment and insight', and improved severe symptom assessment.

A single blind comparative clinical study of the effects of chlorpromazine and risperidone on positive and negative symptoms in patients of schizophrenia

OBJECTIVES

The present study was undertaken to test the comparative efficacy of chlorpromazine and risperidone in patients of schizophrenia in a tertiary care hospital of Maharashtra.

MATERIALS AND METHODS

About 100 subjects of either sex between 15 and 75 years of age were randomly assigned either chlorpromazine or risperidone. Only those patients were included who met International Classification of Diseases 10 revision criteria by World Health Organization. To avoid bias, the test drugs were coded as A and B. The study coordinator was unaware of the prescribed drugs; however, the prescribing psychiatrist knew about the drug treatment.

RESULTS

Both chlorpromazine and risperidone significantly decreased the mean score of positive and general symptoms in patients of schizophrenia. Although chlorpromazine decreased the mean score of negative symptoms, it was not statistically significant. Risperidone reduced the mean score of negative symptoms to a significant extent. The cost (Rs. 3000-4000) of risperidone was more than the cost (Rs. 700-1000) of chlorpromazine per patient per annum. The dropouts were less (25%) in the risperidone group than in the chlorpromazine group (75%). The more purchase of risperidone than of chlorpromazine was observed in our study.

CONCLUSION

The response rates for positive and general symptoms were found to be equal for both chlorpromazine and risperidone. However, risperidone was found to be more effective than chlorpromazine in treating negative symptoms. The dropout rate was less in the risperidone group than in the chlorpromazine group. The compliance was also better in the risperidone group, even though the cost of risperidone was more than that of chlorpromazine.

Antipsychotic medication for early episode schizophrenia

BACKGROUND

Long-term treatment with antipsychotic medications in early episode schizophrenia spectrum disorders is common, but both short and long-term effects on the illness are unclear. There have been numerous suggestions that people with early episodes of schizophrenia appear to respond differently than those with multiple prior episodes. The number of episodes may moderate response to drug treatment.

OBJECTIVES

To assess the effects of antipsychotic medication treatment on people with early episode schizophrenia spectrum disorders.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group register (July 2007) as well as references of included studies. We contacted authors of studies for further data.

SELECTION CRITERIA

Studies with a majority of first and second episode schizophrenia spectrum disorders comparing initial antipsychotic medication treatment with placebo, milieu, or psychosocial treatment.

DATA COLLECTION AND ANALYSIS

Working independently, we critically appraised records from 681studies, of which five studies met inclusion criteria. John Rathbone from the Schizophrenia Group supported us with the data extraction. We calculated risk ratios (RR) and their 95% confidence intervals (CI) where possible. For continuous data, we calculated mean difference (MD). We calculated numbers needed to treat/harm (NNT/NNH) where appropriate.

MAIN RESULTS

Five studies with a combined N = 998 met inclusion criteria. Four studies (N = 724) provided leaving the study early data and results suggested that individuals treated with a typical antipsychotic medication are less likely to leave the study early than those treated with placebo (Chlorpromazine: 3 RCTs N = 353, RR 0.4 CI 0.3 to 0.5, NNT 3.2, Fluphenaxine: 1 RCT N = 240, RR 0.5 CI 0.3 to 0.8, NNT 5; Thioridazine: 1 RCT N = 236, RR 0.44 CI 0.3 to 0.7, NNT 4.3, Trifulperazine: 1 RCT N = 94, RR 0.96 CI 0.3 to 3.6). Two studies (Cole 1964; May 1976) contributed data to assessment of side effects and present a general pattern of more frequent side effects among individuals treated with typical antipsychotic medications compared to placebo. Rappaport 1978 suggested a higher rehospitalisation rate for those receiving chlorpromazine compared to placebo (N = 80, RR 2.29 CI 1.3 to 4.0, NNH 2.9). However, a higher attrition in the placebo group is likely to have introduced a survivor bias into this comparison, as this difference becomes non-significant in a sensitivity analysis on intent-to-treat participants (N = 127, RR 1.69 CI 0.9 to 3.0). One study (May 1976) contributes data to a comparison of trifluoperazine to psychotherapy on long-term health in favour of the trifluoperazine group (N = 92, MD 5.8 CI 1.6 to 0.0); however, data from this study are also likely to contain biases due to selection and attrition. One study (Mosher 1995) contributes data to a comparison of typical antipsychotic medication to psychosocial treatment on six-week outcome measures of global psychopathology (N = 89, MD 0.01 CI -0.6 to 0.6) and global improvement (N = 89, MD -0.03 CI -0.5 to 0.4), indicating no between-group differences. On the whole, there is very little useable data in the few studies meeting inclusion criteria.

AUTHORS' CONCLUSIONS

With only a few studies meeting inclusion criteria, and with limited useable data in these studies, it is not possible to arrive at definitive conclusions. The preliminary pattern of evidence suggests that people with early episode schizophrenia treated with typical antipsychotic medications are less likely to leave the study early, but more likely to experience medication-related side effects. Data are too sparse to assess the effects of antipsychotic medication on outcomes in early episode schizophrenia.

Risperidone dose for schizophrenia

BACKGROUND

Risperidone is a widely used antipsychotic drug for people with schizophrenia. It is important to get a balance between gaining the most positive effects for the least negative outcomes. The optimal dose of risperidone is the focus of this review.

OBJECTIVES

To determine risperidone dose response relationships for schizophrenia and schizophrenia-like psychoses.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Groups Trials Register (July 2008) for all relevant references.

SELECTION CRITERIA

All relevant randomised controlled clinical trials (RCTs).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and resolved disagreement by discussion with a third member of the team. When insufficient data were provided, we contacted the study authors. For homogenous dichotomous data we calculated fixed-effect relative risk (RR) and 95% confidence intervals (CI) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (MD).

MAIN RESULTS

A consistent finding when risperidone ultra low doses (<2 mg/day) were compared with other doses (short-term data) was that more people left early because of insufficient response (n=456, 1 RCT, RR when compared with standard-low (>==4-<6 mg/day) 12.48 CI 1.43 to 4.30). The insufficient response for this low dose is reflected in measures of mental state. When low doses (>==2-<4 mg/day) are used and compared with standard-higher doses (>==6-<10 mg/day) and the high dose range (>==10 mg/day), more people left early because of insufficient response (>==4-<6 mg/day: n=173, 2 RCTs, RR 4.05 CI 1.09 to 15.07; >==10 mg/day: n=173, 2 RCTs, RR 1.92 CI 1.36 to 2.70). For the outcome of 'no clinically important improvement' results favour standard-higher doses (n=272, 2 RCTs, RR 2.26 CI 0.81 to 6.34). When low doses are compared with other higher doses, we found no differences in terms of cardiovascular, CNS, endocrine or gastrointestinal adverse effects. Unspecified EPS were more frequent with the higher doses (>==10 mg: n=262, 2 RCTs, RR 0.45 CI 0.24 to 0.84). One trial did find that endpoint scores on PANSS significantly favoured a low dose when compared with >==4-6 mg/day (n=124, 1 RCT, MD -12.40 CI -17.01 to -7.79). When >==4-<6 mg/day is compared with high doses, less people left early (n=677, 1 RCT, RR leaving any reason 0.74 CI 0.54 to 1.00; n=677, 1 RCT, RR due to adverse effects 0.56 CI 0.32 to 0.97). >==4-<6 mg/day was no worse than >==6-<10 mg/day for 'no clinically important improvement' (n=39, 1 RCT, RR on CGI-I 0.79 CI 0.29 to 2.17). People allocated >==4-<6 mg/day had more movement disorders than those on a low dose (n=124 1 RCT, RR 2.28 CI 1.67 to 3.11). When >==6-<10 mg/day is compared with standard-lower doses and a high dose range, there is no significant difference in terms of proportions leaving early. >==6-<10 mg/day is better than a low dose for 'no clinical important improvement' (n=172, 2 RCTs, RR 0.76 CI 0.61 to 0.94). Overall >==6-<10 mg/day caused less problems especially in EPS when compared with >==10mg/day (n=261, 2 RCTs, RR unspecified EPS 0.56 CI 0.31 to 0.99). When a high dose was compared with a low dose less people left early (n=70, 1 RCT, RR 0.43 CI 0.26 to 0.71) but not when compared with a standard-lower dose (n=677, 1 RCT, RR leaving due to adverse event 1.78 CI 1.03 to 3.09). >==10 mg/day was better than a low dose in terms of 'no clinical important improvement' (n=257, 2 RCTs, RR 0.64 CI 0.50 to 0.82), but worse than a standard-higher dose (>==6-<10 mg/day: n=255, 2 RCTs, RR 1.22 CI 1.00 to 1.51). >==10 mg/day caused more unspecified EPS adverse effects and any drug for adverse events when compared with a standard-higher dose and with a low dose.

AUTHORS' CONCLUSIONS

There is still lack of strong evidence for an optimal dose for clinical practice. The quality of trials suggests that an over estimate of effect is likely and we think this is most probably for the mid-range doses. One such dose (standard-lower dose range, 4-<6 mg/day) does seem optimal for clinical response and adverse effects. Weak evidence suggests that low doses (>==2-<4 mg/day) may be of value for people in their first episode of illness. High doses (>==10 mg/day) did not confer any advantage over any other dose ranges and caused more adverse effects, especially for movement disorders. Ultra low dose (<2 mg/day) seemed useless. We advise the use of dosages from low dose to standard-lower dose for different kinds of individual patients. Future trials should focus on specific populations, e.g. those in their first episode, with acute exacerbation, in relapse or refractory to treatment, and should also test the optimal dose of risperidone over a longer period of time and in the community.

Long-term effects of risperidone versus haloperidol on verbal memory, attention, and symptomatology in schizophrenia

There is evidence in the literature that cognitive functions in schizophrenia (SC) may be improved by atypical neuroleptics (NLPs) in contrast to typical medication, but there is still controversy regarding this apparent superiority of atypical drugs. In this study, we assessed the differential effects of risperidone and haloperidol on verbal memory, attention, and psychiatric symptoms in SC. The performance of 28 SC participants, randomly assigned to risperidone (2-6 mg/day) or haloperidol (2-40 mg/day), was compared with that of healthy controls. The California Verbal Learning Test (CVLT), the d2 Cancellation Test, and the Positive and Negative Symptoms Scale were administered at baseline and 3, 6, and 12 months. Relative to controls, all SC participants showed markedly impaired verbal memory and processing speed at each assessment period. There was no differential effect between the two NLPs on CVLT and d2 performance. However, risperidone was more effective than haloperidol in reducing psychiatric symptoms. Improvement in symptom severity was not associated with improvement in neurocognitive performance on these specific tests. Neither conventional nor atypical neuroleptic medications improved neurocognitive functioning over a 12-month follow-up, suggesting that psychopathological improvement under risperidone is independent of cognitive function.

Clinical Pharmacokinetics of Atypical Antipsychotics

In the past, the information about the dose-clinical effectiveness of typical antipsychotics was not complete and this led to the risk of extrapyramidal adverse effects. This, together with the intention of improving patients' quality of life and therapeutic compliance, resulted in the development of atypical or second-generation antipsychotics (SGAs). This review will concentrate on the pharmacokinetics and metabolism of clozapine, risperidone, olanzapine, quetiapine, amisulpride, ziprasidone, aripiprazole and sertindole, and will discuss the main aspects of their pharmacodynamics. In psychopharmacology, therapeutic drug monitoring studies have generally concentrated on controlling compliance and avoiding adverse effects by keeping long-term exposure to the minimal effective blood concentration. The rationale for using therapeutic drug monitoring in relation to SGAs is still a matter of debate, but there is growing evidence that it can improve efficacy, especially when patients do not respond to therapeutic doses or when they develop adverse effects. Here, we review the literature concerning the relationships between plasma concentrations of SGAs and clinical responses by dividing the studies on the basis of the length of their observation periods. Studies with clozapine evidenced a positive relationship between plasma concentrations and clinical response, with a threshold of 350-420 ng/mL associated with good clinical response. The usefulness of therapeutic drug monitoring is well established because high plasma concentrations of clozapine can increase the risk of epileptic seizures. Plasma clozapine concentrations seem to be influenced by many factors such as altered cytochrome P450 1A4 activity, age, sex and smoking. The pharmacological effects of risperidone depend on the sum of the plasma concentrations of risperidone and its 9-hydroxyrisperidone metabolite, so monitoring the plasma concentrations of the parent compound alone can lead to erroneous interpretations. Despite a large variability in plasma drug concentrations, the lack of studies using fixed dosages, and discrepancies in the results, it seems that monitoring the plasma concentrations of the active moiety may be useful. However, no therapeutic plasma concentration range for risperidone has yet been clearly established. A plasma threshold concentration for parkinsonian side effects has been found to be 74 ng/mL. Moreover, therapeutic drug monitoring may be particularly useful in the switch between the oral and the long-acting injectable form. The reviewed studies on olanzapine strongly indicate a relationship between clinical outcomes and plasma concentrations. Olanzapine therapeutic drug monitoring can be considered very useful in assessing therapeutic efficacy and controlling adverse events. A therapeutic range of 20-50 ng/mL has been found. There is little evidence in favour of the existence of a relationship between plasma quetiapine concentrations and clinical responses, and an optimal therapeutic range has not been identified. Positron emission tomography studies of receptor blockade indicated a discrepancy between the time course of receptor occupancy and plasma quetiapine concentrations. The value of quetiapine plasma concentration monitoring in clinical practice is still controversial. Preliminary data suggested that a therapeutic plasma amisulpride concentration of 367 ng/mL was associated with clinical improvement. A therapeutic range of 100-400 ng/mL is proposed from non-systematic clinical experience. There is no direct evidence concerning optimal plasma concentration ranges of ziprasidone, aripiprazole or sertindole.

Clinical trials for antipsychotic drugs: design conventions, dilemmas and innovations

More than 50 years after the introduction of modern pharmacotherapies for schizophrenia, there remains a tremendous need for therapeutic advances. A second generation of antipsychotic drugs, introduced over the past 15 years, has provided uncertain advantages over the first-generation drugs. This paper reviews the designs of studies that evaluate the effectiveness of putative antipsychotic drugs. Data from the trials needed to achieve regulatory approval do not meet all the needs of clinicians and policy makers. Practical and large, simple trials that evaluate the comparative effectiveness of antipsychotic drugs in real-world settings can help to meet these needs once a drug has reached the market.

The effect of neuroleptic treatments on executive function and symptomatology in schizophrenia: a 1-year follow up study

Cognitive dysfunctions (as in memory, attention and executive function) have been recognized as fundamental features of schizophrenia. Executive dysfunction is a major obstacle to functional outcome, community functioning and rehabilitation success and it is crucial to assess the effects of so-called neuroleptic (NLP) medications in this domain of cognitive functioning. Risperidone, an atypical NLP, has been reported to improve executive function in schizophrenia (SZ), but there is controversy regarding these findings. The aim of the current study was to assess the differential effects of risperidone (2-6 mg) and conventional (2-40 mg haloperidol) NLPs on executive skills in 31 individuals with SZ over a 12-month period. The performance of both NLP groups was compared to the performance of 17 age- and education-matched healthy controls. In this randomized, double blind study, the Wisconsin Card Sorting Test (WCST) was administered at baseline, 3, 6, and 12 months after initiating medication. The relationship between executive functioning and the course of clinical symptoms, as assessed by the Positive and Negative Syndrome Scale (PANSS) was also investigated. Results showed that, relative to healthy controls, individuals with SZ showed marked impairment in WCST from baseline through 12 months of treatment. Also, participants under haloperidol or risperidone NLP medication performed similarly on the WCST at all assessment periods showing that risperidone and haloperidol do not differ in their effect on executive functioning. Risperidone treatment, however, was more effective in the reduction of negative symptoms. The differential efficacy of risperidone over negative symptoms and WCST performance strongly suggests that the executive impairments are to some extent the result of brain abnormalities independent of those that produce the major psychopathology manifestations seen in SZ.

An analysis of the effect of funding source in randomized clinical trials of second generation antipsychotics for the treatment of schizophrenia

OBJECTIVE

The effect of funding source on the outcome of randomized controlled trials has been investigated in several medical disciplines; however, psychiatry has been largely excluded from such analyses. In this article, randomized controlled trials of second generation antipsychotics in schizophrenia are reviewed and analyzed with respect to funding source (industry vs. non-industry funding).

METHOD

A literature search was conducted for randomized, double-blind trials in which at least one of the tested treatments was a second generation antipsychotic. In each study, design quality and study outcome were assessed quantitatively according to rating scales. Mean quality and outcome scores were compared in the industry-funded studies and non-industry-funded studies. An analysis of the primary author's affiliation with industry was similarly performed.

RESULTS

Results of industry-funded studies significantly favored second generation over first generation antipsychotics when compared to non-industry-funded studies. Non-industry-funded studies showed a trend toward higher quality than industry-funded studies; however, the difference between the two was not significant. Also, within the industry-funded studies, outcomes of trials involving first authors employed by industry sponsors demonstrated a trend toward second generation over first generation antipsychotics to a greater degree than did trials involving first authors employed outside the industry (p=0.05).

CONCLUSIONS

While the retrospective design of the study limits the strength of the findings, the data suggest that industry bias may occur in randomized controlled trials in schizophrenia. There appears to be several sources by which bias may enter clinical research, including trial design, control of data analysis and multiplicity/redundancy of trials.

Relapse in patients with schizophrenia: a comparison between risperidone and haloperidol

OBJECTIVES

To compare rates of rehospitalization and time to relapse in risperidone vs. haloperidol-treated schizophrenic patients discharged from the hospital.

METHODS

Randomized controlled trial comparing risperidone and haloperidol regarding relapse in patients with schizophrenia treated with flexible doses during one year.

RESULTS

Twenty patients were assigned to risperidone and 13 to haloperidol. One patient from each group withdrew consent and one patient in the risperidone group was lost for follow-up. Six (30.0%) patients in the risperidone group and 3 (23.1%) in the haloperidol group relapsed (p=1.00). However, time to relapse was shorter in the later (logrank =4.2; p=.04). When rehospitalized, patients in the risperidone group stayed 34.5 days (median) at hospital as compared to the haloperidol group (median of 61 days) (p=.61).

CONCLUSION

The proportion of schizophrenic patients who relapsed was similar in both groups; However, time to relapse was shorter in the haloperidol-treated patients.

The new and evolving pharmacotherapy of schizophrenia

Based on the evidence presented here, the following tentative conclusions can be drawn. Atypical antipsychotics (except amisulpride) have shown superiority over placebo in acute schizophrenia. Compared with conventional antipsychotics, they are at least as effective. Generally, analyses employing conservative criteria (e.g., Cochrane reviews) report few efficacy differences between atypical and conventional agents. There are now many well-controlled studies indicating modest advantages for the atypical antipsychotics, however, particularly in specific symptom domains. For the treatment of negative symptoms, olanzapine and to a lesser extent amisulpride seem most promising. Risperidone, olanzapine, and quetiapine display advantages in improving cognitive and depressive symptoms. There are indications that the atypical antipsychotics are associated with decreased likelihood of rehospitalization and improved quality of life. In head-to-head comparisons of atypical antipsychotics, none have shown consistent efficacy advantages. In severely refractory samples, no atypical antipsychotics have consistently been shown to be as effective as clozapine or superior to conventional agents. There are indications, however, that risperidone, olanzapine, and quetiapine have advantages over conventional agents in less severely refractory patients. Few maintenance RCTs have been published, and efficacy advantages for atypical antipsychotics in prospective RCTs in first-episode schizophrenia have not been reported.