Conceptual and methodological issues in the design of clinical trials of antipsychotics for the treatment of schizophrenia

Differential Effects of Acute Treatment With Antipsychotic Drugs on Peripheral Catecholamines

Antipsychotic drugs represent the most effective treatment for chronic psychotic disorders. The newer second generation drugs offer the advantage of fewer neurological side-effects compared to prior drugs, but many cause serious metabolic side-effects. The underlying physiology of these side-effects is not well-understood, but evidence exists to indicate that the sympathetic nervous system may play an important role. In order to examine this possibility further, we treated separate groups of adult female rats acutely with either the first generation antipsychotic drug haloperidol (0.1 or 1 mg/kg) or the second generation drugs risperidone (0.25 or 2.5 mg/kg), clozapine (2 or 20 mg/kg), olanzapine (3 or 15 mg/kg) or vehicle by intraperitoneal injection. Blood samples were collected prior to drug and then 30, 60, 120, and 180 mins after treatment. Plasma samples were assayed by HPLC-ED for levels of norepinephrine, epinephrine, and dopamine. Results confirmed that all antipsychotics increased peripheral catecholamines, although this was drug and dose dependent. For norepinephrine, haloperidol caused the smallest maximum increase (+158%], followed by risperidone (+793%), olanzapine (+952%) and clozapine (+1,684%). A similar pattern was observed for increases in epinephrine levels by haloperidol (+143%], olanzapine (+529%), risperidone (+617%) then clozapine (+806%). Dopamine levels increased moderately with olanzapine [+174%], risperidone [+271%], and clozapine [+430%]. Interestingly, levels of the catecholamines did not correlate strongly with each other prior to treatment at baseline, but were increasingly correlated after treatment as time proceeded. The results demonstrate antipsychotics can potently regulate peripheral catecholamines, in a manner consistent with their metabolic liability.

Clozapine-Induced Cardiovascular Side Effects and Autonomic Dysfunction: A Systematic Review

Background: Clozapine is the antipsychotic of choice for treatment-resistant schizophrenia and has minimal risk for extrapyramidal symptoms. Therapeutic benefits, however, are accompanied by a myriad of cardiometabolic side-effects. The specific reasons for clozapine's high propensity to cause adverse cardiometabolic events remain unknown, but it is believed that autonomic dysfunction may play a role in many of these.

Objective: This systematic review summarizes the literature on autonomic dysfunction and related cardiovascular side effects associated with clozapine treatment.

Method: A search of the EMBASE, MEDLINE, and EBM Cochrane databases was conducted using the search terms antipsychotic agents, antipsychotic drug^*, antipsychotic^*, schizophrenia, schizophren^*, psychos^*, psychotic^*, mental ill^*, mental disorder^*, neuroleptic^*, cardiovascular^*, cardiovascular diseases, clozapine^*, clozaril^*, autonomic^*, sympathetic^*, catecholamine^*, norepinephrine, noradrenaline, epinephrine, adrenaline.

Results: The search yielded 37 studies that were reviewed, of which only 16 studies have used interventions to manage cardiovascular side effects. Side effects reported in the studies include myocarditis, orthostatic hypotension and tachycardia. These were attributed to sympathetic hyperactivity, decreased vagal contribution, blockade of cholinergic and adrenergic receptors, reduced heart rate variability and elevated catecholamines with clozapine use. Autonomic neuropathy was identified by monitoring blood pressure and heart rate changes in response to stimuli and by spectral analysis of heart rate variability. Metoprolol, lorazepam, atenolol, propranolol, amlodipine, vasopressin and norepinephrine infusion were used to treat tachycardia and fluctuations in blood pressure, yet results were limited to case reports.

Conclusion: The results indicate there is a lack of clinical studies investigating autonomic dysfunction and a limited use of interventions to manage cardiovascular side effects associated with clozapine. As there is often no alternative treatment for refractory schizophrenia, the current review highlights the need for better designed studies, use of autonomic tests for prevention of cardiovascular disease and development of novel interventions for clozapine-induced side effects.

Development of a cost-efficient novel method for rapid, concurrent genotyping of five common single nucleotide polymorphisms of the brain derived neurotrophic factor (BDNF) gene by tetra-primer amplification refractory mutation system

Brain derived neurotrophic factor (BDNF) is a molecular trophic factor that plays a key role in neuronal survival and plasticity. Single nucleotide polymorphisms (SNPs) of the BDNF gene have been associated with specific phenotypic traits in a large number of neuropsychiatric disorders and the response to psychotherapeutic medications in patient populations. Nevertheless, due to study differences and occasionally contrasting findings, substantial further research is required to understand in better detail the association between specific BDNF SNPs and these psychiatric disorders. While considerable progress has been made recently in developing advanced genotyping platforms of SNPs, many high-throughput probe- or array-based detection methods currently available are limited by high costs, slow processing times or access to advanced instrumentation. The polymerase chain reaction (PCR)-based, tetra-primer amplification refractory mutation system (T-ARMS) method is a potential alternative technique for detecting SNP genotypes efficiently, quickly, easily, and cheaply. As a tool in psychopathology research, T-ARMS was shown to be capable of detecting five common SNPs in the BDNF gene (rs6265, rs988748, rs11030104, 11757G/C and rs7103411), which are all SNPs with previously demonstrated clinical relevance to schizophrenia and depression. The present technique therefore represents a suitable protocol for many research laboratories to study the genetic correlates of BDNF in psychiatric disorders. Copyright Copyright © 2015 John Wiley & Sons, Ltd.

An evaluation of the effects of the novel antipsychotic drug lurasidone on glucose tolerance and insulin resistance: a comparison with olanzapine

Over the past two decades, there has been a notable rise in the use of antipsychotic drugs, as they are used to treat an increasing number of neuropsychiatric disorders. This rise has been led predominantly by greater use of the second generation antipsychotic (SGA) drugs, which have a low incidence of neurological side-effects. However, many SGAs cause metabolic dysregulation, including glucose intolerance and insulin resistance, thus increasing the risk of cardiometabolic disorders. The metabolic effects of the novel SGA lurasidone, which was approved by the Food and Drug Administration in 2010, remain largely unknown. As rodent models accurately predict the metabolic effects of SGAs in humans, the aim of the present study was to use sophisticated animal models of glucose tolerance and insulin resistance to measure the metabolic effects of lurasidone. In parallel, we compared the SGA olanzapine, which has established metabolic effects. Adult female rats were treated with vehicle, lurasidone (0.2, 0.8 or 2.0 mg/kg, s.c.) or olanzapine (10.0 mg/kg, s.c.) and subjected to the glucose tolerance test (GTT). Separate groups of rats were treated with vehicle, lurasidone (0.2, 0.8 or 2.0 mg/kg, s.c.) or olanzapine (1.5 and 15 mg/kg, s.c.) and tested for insulin resistance with the hyperinsulinemic-euglycemic clamp (HIEC). Compared to vehicle treated animals, lurasidone caused mild glucose intolerance in the GTT with a single dose, but there was no effect on insulin resistance in the GTT, measured by HOMA-IR. The HIEC also confirmed no effect of lurasidone on insulin resistance. In contrast, olanzapine demonstrated dose-dependent and potent glucose intolerance, and insulin resistance in both tests. Thus, in preclinical models, lurasidone demonstrates mild metabolic liability compared to existing SGAs such as olanzapine. However, confirmation of these effects in humans with equivalent tests should be confirmed.

Antidiabetic-drug combination treatment for glucose intolerance in adult female rats treated acutely with olanzapine

Second generation antipsychotic drugs are routinely used as treatment for psychotic disorders. Many of these compounds, including olanzapine, cause metabolic side-effects such as impaired glucose tolerance and insulin resistance. Individual antidiabetic drugs can help control elevated glucose levels in patients treated with antipsychotics, but the effects of combining antidiabetics, which routinely occurs with Type 2 diabetes mellitus patients, have never been studied. Presently, we compared the effects of the three different antidiabetics metformin (500mg/kg, p.o.), rosiglitazone (30mg/kg, p.o.) and glyburide (10mg/kg, p.o.) on metabolic dysregulation in adult female rats treated acutely with olanzapine. In addition, dual combinations of each of these antidiabetics were compared head-to-head against each other and the individual drugs. The animals received two daily treatments with antidiabetics and were then treated acutely with olanzapine (10mg/kg, i.p.). Fasting glucose and insulin levels were measured, followed by a 2h glucose tolerance test. Olanzapine caused a large and highly significant glucose intolerance compared to vehicle treated rats. Rosiglitazone decreased glucose levels non-significantly, while both metformin and glyburide significantly decreased glucose levels compared to olanzapine-only treated animals. For antidiabetic dual-drug combinations, the rosiglitazone-metformin group showed an unexpected increase in glucose levels compared to all of the single antidiabetic drugs. However, both the metformin-glyburide and rosiglitazone-glyburide groups showed significantly greater reductions in glucose levels following olanzapine than with single drug treatment alone for metformin or rosiglitazone, bringing glucose levels down to values equivalent to vehicle-only treated animals. These findings indicate that further study of antidiabetic dual-drug combinations in patients treated with antipsychotic drugs is warranted.

Real-world effectiveness of antipsychotic monotherapy vs. polypharmacy in schizophrenia: to switch or to combine? A nationwide study in Hungary

BACKGROUND

Leading guidelines recommend antipsychotic (AP) monotherapy for schizophrenia, nonetheless the combination of antipsychotics (polypharmacy) is common practice worldwide. We conducted a nationwide population-based study to investigate the comparative effectiveness of monotherapy versus polypharmacy in schizophrenia and other psychotic disorders.

METHODS

Data was collected from the Hungarian National Health Insurance Fund's database and a non-interventional retrospective-prospective parallel arm study was designed with a monotherapy arm (MA, switch to a new antipsychotic after >60 days of monotherapy, N=5480) and a polypharmacy arm with two APs (PA, addition of a second antipsychotic after >60 days of monotherapy, N=7901). The analyses focused on therapy changers, who started a new monotherapy or added a new AP to the existing one. Polypharmacy combinations with more than two APs were not investigated. Fourteen APs were investigated representing the majority of marketed antipsychotics of Hungary in the period of 1/2007-12/2009. The principal endpoint was the time to all-cause treatment discontinuation during a one-year observation period. Kaplan-Meier survival analysis and Cox proportional hazards model were applied with propensity score adjustment.

RESULTS

The principal outcome measure time to all-cause discontinuation indicated superiority for monotherapy over polypharmacy for the majority of (oral and depot) second generation APs (SGAs). For first generation APs (FGAs), oral formulations did not show a difference between monotherapy and polypharmacy, while depot formulations exhibited polypharmacy advantage. For the four most frequently used oral SGAs, the median times to all-cause discontinuation for monotherapy and polypharmacy, respectively, were 192 and 100 days for aripiprazole; 222 and 86 days for olanzapine; 176 and 91 days for quetiapine; and 157 and 93 days for risperidone. For mortality and hospitalization, a significant overall advantage of polypharmacy was detected.

CONCLUSIONS

Our study provides evidence for the superiority of monotherapy over polypharmacy for SGAs in terms of all-cause treatment discontinuation in schizophrenia. Polypharmacy, however, was associated with a lower likelihood of mortality and hospitalizations. The finding that MA is superior to PA for long-term sustained treatment whereas polypharmacy has advantage in mortality and psychiatric hospitalizations suggests that combination treatments may be more efficacious during exacerbation of psychotic symptoms.

Improving metabolic and cardiovascular health at an early psychosis intervention program in vancouver, Canada

Psychotic disorders most commonly appear during the late teenage years and early adulthood. A focused and rapid clinical response by an integrated health team can help to improve the quality of life of the patient, leading to a better long-term prognosis. The Vancouver Coastal Health early psychosis intervention program covers a catchment area of approximately 800,000 people in the cities of Vancouver and Richmond, Canada. The program provides a multidisciplinary approach to supporting patients under the age of 30 who have recently experienced first-break psychosis. The program addresses the needs of the treatment environment, medication, and psychological therapies. A critical part of this support includes a program to specifically improve patients' physical health. Physical health needs are addressed through a two-pronged, parallel approach. Patients receive routine metabolic health assessments during their first year in the program, where standard metabolic parameters are recorded. Based on the results of clinical interviews and laboratory tests, specific actionable interventions are recommended. The second key strategy is a program that promotes healthy lifestyle goal development. Patients work closely with occupational therapists to develop goals to improve cardiometabolic health. These programs are supported by an active research environment, where patients are able to engage in studies with a focus on improving their physical health. These studies include a longitudinal evaluation of the effects of integrated health coaching on maintaining cardiometabolic health in patients recently admitted to the program, as well as a clinical study that evaluates the effects of low versus higher metabolic risk antipsychotic drugs on central adiposity. An additional pharmacogenomic study is helping to identify genetic variants that may predict cardiometabolic changes following treatment with antipsychotic drugs.

Short-term remission in schizophrenia as a combination of several outcome measures

Clinical, cognitive, metabolic and functioning variables have been evaluated in patients with schizophrenia in an 8-week trial with Ziprasidone. The aim of this post-hoc analysis is to investigate how these variables interact in determining short-term remission. Baseline values or the variation from baseline to endpoint were considered predictors. 262 schizophrenic patients were recruited. Two logistic regressions were conducted to determine which variables predict remission. The first was performed on baseline values as predictors. The second used the variation from baseline to endpoint (delta) of the outcome evaluations as predictors. Using literature reported criteria for remission, we distinguished 124 subjects (47.33%) in remission, and 138 not in remission at the end of the trial. The first logistic regression does not show a good fit. The second logistic regression, with delta scores as predictors, reports instead an overall good fit (71.8% of the predicted cases assigned to the right category). The analysis reveals that general score from Positive and Negative Syndrome Scale (PANSS), cholesterol LDL, subjective well-being under neuroleptic, Simpson-Angus Scale (SAS) delta scores, drug dosage and premorbid intelligence entered in the equation. These results suggest that indexes such as cognition, metabolic status, other than symptoms, have to be taken into account in order to refine the short-term remission prediction.

A retrospective study of antipsychotic drug switching in a pediatric population

BACKGROUND

Antipsychotic drugs can be used to help treat a wide variety of psychiatric disorders. However, specific antipsychotic drugs for any particular patient may need to be changed for a number of different reasons, including a lack of therapeutic efficacy and / or intolerance to medication side-effects. Drug switching may occur through a limited number of established patterns. The nature of these changes is not well characterized in youth, despite their frequent occurrence.

METHODS

A retrospective analysis of antipsychotic drug switches was conducted on patients who had been admitted as inpatients to a tertiary care child and adolescent psychiatric institute. PharmaNet (a large, central administrative database) records of all medications prescribed in the 52 weeks prior to admission, and then between admission and discharge, were analyzed for switching patterns. Additional data regarding diagnoses were obtained from medical chart review.

RESULTS

Patients represented a diagnostically heterogeneous population, and almost all antipsychotic drugs were administered off-label. In the one year prior to and during admission to the hospital, a total of 31 out of 139 patients switched antipsychotic drugs. The frequency of switching increased closer to the time of admission, and the proportional rate of switching was even higher during hospital stay. The most common switch was from risperidone to quetiapine. Our analysis identified three main patterns of drug switching, all occurring with similar frequency: titrated drug switches, abrupt drug switches and concurrent drug administration.

CONCLUSIONS

The present study indicates that antipsychotic drug switching in youth may be relatively common, particularly in the year prior to hospitalization. No specific manner of drug switching predominates. This study also demonstrates the feasibility of using large administrative databases to characterise switching patterns in youth.

Changes in cognitive function associated with syndrome changes on two five-factor models of the Positive and Negative Syndrome Scale

OBJECTIVE

This study aims to examine the association between neuropsychological function and symptom changes over time on two five-factor models, pentagonal (PM) and Van der Gaag (VDG), of the Positive and Negative Syndrome Scale (PANSS) and to determine the added value of these syndrome models for interpreting neuropsychological changes.

METHODS

Data were collected in a randomized controlled trial comparing second-generation and conventional antipsychotic medications for 108 adult patients diagnosed with schizophrenia and monitored prospectively for 12 months using standard neuropsychological instruments and the PANSS. Random-effects regression was used to estimate the change over time in neuropsychological function and the association of PANSS covariates.

RESULTS

Improvements in positive, negative, and cognitive syndromes were significant predictors of change on nine neuropsychological measures. The neuropsychological function was worsening on five of these measures. The PM model represented the best set of predictors examining positive and negative syndrome covariates, whereas the VDG model consistently represented the best predictors examining cognitive syndrome covariates.

CONCLUSIONS

The PM positive and negative syndrome factors and the VDG disorganized thoughts syndrome factor are differentially associated with changes in neuropsychological function over time. Clinical investigators may want to target their use of these factors from the PANSS according to the outcome variables being measured.

Differential effects of 3 classes of antidiabetic drugs on olanzapine-induced glucose dysregulation and insulin resistance in female rats

BACKGROUND

The second-generation antipsychotic drug olanzapine is an effective pharmacological treatment for psychosis. However, use of the drug is commonly associated with a range of metabolic side effects, including glucose intolerance and insulin resistance. These symptoms have been accurately modelled in rodents.

METHODS

We compared the effects of 3 distinct classes of antidiabetic drugs, metformin (100 and 500 mg/kg, oral), rosiglitazone (6 and 30 mg/kg, oral) and glyburide (2 and 10 mg/kg, oral), on olanzapineinduced metabolic dysregulation. After acutely treating female rats with lower (7.5 mg/kg) or higher (15 mg/kg) doses of olanzapine, we assessed glucose intolerance using the glucose tolerance test and measured insulin resistance using the homeostatic model assessment of insulin resistance equation.

RESULTS

Both doses of olanzapine caused pronounced glucose dysregulation and insulin resistance, which were significantly reduced by treatment with metformin and rosiglitazone; however, glucose tolerance did not fully return to control levels. In contrast, glyburide failed to reverse the glucose intolerance caused by olanzapine despite increasing insulin levels.

LIMITATIONS

We evaluated a single antipsychotic drug, and it is unknown whether other antipsychotic drugs are similarly affected by antidiabetic treatments.

CONCLUSION

The present study indicates that oral hypoglycemic drugs that influence hepatic glucose metabolism, such as metformin and rosiglitazone, are more effective in regulating olanzapine-induced glucose dysregulation than drugs primarily affecting insulin release, such as glyburide. The current model may be used to better understand the biological basis of glucose dysregulation caused by olanzapine and how it can be reversed.

Intermittent treatment with olanzapine causes sensitization of the metabolic side-effects in rats

The second generation antipsychotic drugs are effective treatments for psychotic disorders. Many of these compounds, including the drug olanzapine, have been associated with metabolic side-effects, including weight gain, impaired glucose tolerance and insulin resistance, which increase the risk of developing cardiometabolic disorders. Rodent models of olanzapine-induced metabolic side-effects have been used to study the physiology of these effects, but only at a single time point after drug treatment. The purpose of the present study was to examine longitudinal changes with chronic antipsychotic drug treatment. Adult female rats were treated with either olanzapine (15 mg/kg) or vehicle for five consecutive days each week, followed by a 48 h washout period. Animals were then challenged with either olanzapine (15 mg/kg) or vehicle, and fasting glucose and insulin values were recorded, as well as glucose clearance in the glucose tolerance test. Treatment with olanzapine was continued for 10 weeks, with weekly tests of metabolic indices. Rats treated acutely with olanzapine showed both glucose dysregulation and insulin resistance; for the group treated during the week with olanzapine, these effects did not change by the end of ten weeks of treatment. However, in the group of animals challenged only once per week with olanzapine, the metabolic side-effects markedly intensified with the passage of time, whereby glucose intolerance and insulin resistance increased significantly compared to both baseline values and all other treatment groups. This previously unreported sensitization phenomenon represents a novel finding that may have clinical implications for patients receiving intermittent antipsychotic drug dosing or with variable adherence to treatment.

A parametric study of the acute effects of antipsychotic drugs on glucose sensitivity in an animal model

The therapeutic use of atypical antipsychotics is associated with a high incidence of metabolic side-effects. In the present study we examined the acute effects of both high and low-dose atypical antipsychotic drugs and one typical drug on alterations in glucose and insulin parameters using a rodent model. The effects of administration of clozapine (2mg/kg; 20mg/kg), olanzapine (1.5mg/kg; 15 mg/kg), risperidone (0.5mg/kg; 2.5mg/kg) and haloperidol (0.1mg/kg; 1.0mg/kg) on glucose sensitivity and insulin resistance were determined through HOMA-IR values in fasted rats and glucose clearance during a glucose tolerance test. Acute effects were determined 60, 180 or 360 min following drug administration. The atypical antipsychotics produced significant dose and time dependent effects on fasting plasma glucose and insulin concentrations, HOMA-IR values, insulin resistance and glucose intolerance. The greatest effect on glucose dysregulation was noted primarily with clozapine and olanzapine; however, all four treatments caused significant increases in fasting glucose and/or insulin levels with the high dose, 60 min post-drug administration. Together, these findings indicate that acute administration of antipsychotic drugs has potent effects on metabolic regulation of glucose and insulin sensitivities, which may contribute to metabolic side-effects seen in humans.

Remission in schizophrenia: one-year Italian prospective study of risperidone long-acting injectable (RLAI) in patients with schizophrenia or schizoaffective disorder

OBJECTIVES

To evaluate the maintenance of efficacy of risperidone long-acting injectable (RLAI) in stable patients with schizophrenia or schizoaffective disorders. The prevalence of patients who met standardized remission criteria will be also evaluated as well as the predictors factors of remission according to psychopathological, psychosocial and subjective correlates.

METHODS

52-week, open-label prospective trial in 347 stable patients switching directly to RLAI from any previous antipsychotic treatment.

RESULTS

One year of treatment was completed by 70% of patients. Positive and Negative Syndrome Scale (PANSS) total and subscale, Global Assessment of Functioning (GAF) and Clinical Global Impression (CGI) scores improved from baseline at each assessment visit (p < 0.001, p < 0.001 and p < 0.05, respectively). Drug Attitude Inventory 30 (DAI30) scores improved significantly from month 3 onwards. 32% of patients met sustained remission at week 52. In a logistic regression model less severe positive and negative PANSS scores at baseline predicted remission (p < 0.001). RLAI treatment was well tolerated: one-third of patients reported mild to moderate adverse events (AEs). Eleven patients (3.2%) discontinued treatment due to an AE. No significant weight gain (p = 0.093) was reported.

CONCLUSIONS

RLAI treatment up to one year improved symptoms and global functioning versus baseline, indicating that an established and accepted antipsychotic therapy can enable patients with schizophrenia to achieve and maintain remission.

Bridging bench and practice: translational research for schizophrenia and other psychotic disorders

Translational research is urgently needed to turn basic scientific discoveries into widespread health gains and nowhere are these needs greater than in conditions such as schizophrenia and other psychotic disorders. In this article, we discuss one type of translational research--called T1--which is needed to take advantage of developments in the basic neurosciences and translate them into more efficacious diagnostic, preventive, and therapeutic interventions. However, ensuring that interventions from T1 research actually benefit patients will require a second form of translational research--called T2--to turn innovations into everyday clinical practice and health decision-making. Recent examples of T1 and T2 research in schizophrenia and other psychotic disorders as well as strategies for better linking T1 and T2 research agendas are covered.

World Psychiatric Association Pharmacopsychiatry Section statement on comparative effectiveness of antipsychotics in the treatment of schizophrenia

Data from two major government-funded studies of comparative antipsychotic effectiveness in schizophrenia contradict the widely prevalent belief that the newer second-generation medications are vastly superior to the older first-generation drugs. This has caused uncertainty among patients, clinicians and policy-makers about the relative utility of first- and second- generation antipsychotic agents in its treatment. To reduce confusion and provide a contextual understanding of the new data, the World Psychiatry Association Section on Pharmacopsychiatry comprehensively reviewed the literature on the comparative effectiveness of different antipsychotic treatments for schizophrenia and developed this update. Utilizing data from the approximately 1,600 randomized controlled trials of antipsychotic treatment in schizophrenia, we applied the two indirect and one direct method to comparing the effectiveness of 62 currently-available antipsychotic agents. The subclasses of 51 first-generation and 11 second-generation antipsychotics were both found to be very heterogeneous, with substantial differences in side-effect profiles among members. Second-generation antipsychotic agents were found to be inconsistently more effective than first-generation agents in alleviating negative, cognitive, and depressive symptoms and had a lower liability to cause tardive dyskinesia; these modest benefits were principally driven by the ability of second-generation antipsychotics to provide equivalent improvement in positive symptoms along with a lower risk of causing extrapyramidal side-effects. Clozapine was found to be more efficacious than other agents in treatment-refractory schizophrenia. There were no consistent differences in efficacy among other second-generation antipsychotic agents; if such differences exist, they are likely small in magnitude. Dosing was found to be a key variable in optimizing effectiveness of both first- and second- generation antipsychotic agents. There was enormous individual variability in antipsychotic response and vulnerability to various adverse effects. In contrast to their relatively similar efficacy in treating positive symptoms, there were substantial differences among both first- and second- generation antipsychotic agents with regard to their propensity to cause extrapyramidal, metabolic and other adverse effects; second-generation agents have a lower liability to cause acute extrapyramidal symptoms and tardive dyskinesia along with a tendency to cause greater metabolic side-effects than first-generation agents. Based on these data about the comparative effectiveness of different antipsychotic treatment options, we summarize elements of current best antipsychotic practice for the treatment of schizophrenia and discuss the role of government and the pharmaceutical industry in obtaining and disseminating information which can facilitate best practice.