Neuroleptic treatment of negative symptoms in schizophrenic patients. Efficacy problems and methodological difficulties

Placebo controlled studies in acute schizophrenia – an issue of concern

Placebo controlled studies in patients suffering from exacerbation eg acute productive episode of schizophrenia and performed in the period between 1963-1993 are reviewed and analysed with respect to study designs; size of studies; improvement rate under placebo and drop-outs due to inefficacy under placebo. The aim of the analysis was to find out if the reported data permit some realistic estimates for a priori assumptions needed for proper planning of such studies, particularly in view of the numerous ethical and other difficulties which their performance encounters in the practice. Literature research revealed a rather limited number of rigorous, placebo-controlled, monotherapy studies (without intermittent or concomitant additional neuroleptics) in acute schizophrenia. Across comparison of findings from these studies was difficult due to differences in duration of treatment, assessment instruments and criteria of efficacy which illustrated a lack of methodological standards for studies in this indication. The improvement rate under placebo, if measured by Clinical Global Assessment (CGI) appeared, however, not to exceed 25%, whereas BPRS score reduction as efficacy criterion mostly provided higher response rates (up to 40%). Of interest however, is the finding that the response rate to conventional neuroleptics at the end of 4-6 weeks of treatment in some studies hardly exceeded 40%. The most sensitive measure of placebo effect seemed to be the drop-out rate due to inefficacy (up to 100%) and it is suggested to consider this measure and the survival analysis approach in designing future studies. The review demonstrated many unresolved methodological problems in testing antipsychotic drugs in acute schizophrenia and, particularly, the need of scientific evidence of validity and sensitivity of measures of antipsychotic efficacy. The findings reported up to now do not offer cues for rational estimates of the effect size differences between placebo and active drugs after short-term treatment in acute schizophrenia.

Long-term studies of antipsychotic drugs in schizophrenia

Studies on long-term efficacy and safety should be a main concern in the evaluation of novel antipsychotics. The present paper is a review of important issues related to the design and performance of such trials. The variability of the natural course of schizophrenia, the variability in treatment response, and the variability of actions of different neuroleptics need to be considered. Long-term studies need to address maintenance of efficacy, prevention of relapse and recurrence, health economics, quality of life and a large number of safety issues in order to get approval for new drug applications and reimbursement on expensive new medicines. Assessment instruments for efficacy, tolerability and safety, need to be supplemented with rating scales for various aspects of psychopathology (positive, negative, deficit symptoms), social and work functioning, drug induced mental side effects, quality of life and accounts of total treatment costs.

Review and meta-analysis of usage of ginkgo as an adjunct therapy in chronic schizophrenia

This study aimed to review the roles of antioxidants in the pathophysiology of schizophrenia, whether the properties of ginkgo can ameliorate symptoms of this illness, and evaluate available literature to test this assumption. This review is based upon published works on antioxidants and ginkgo. A primary electronic search for meta-analysis on the usage of ginkgo or its derived products in schizophrenia was conducted using Pubmed, Cochrane Library, EMBASE, CINAHL, PsycINFO and AMED. Inclusion criteria were: criteria-based diagnosis of schizophrenia, randomized case assignment, use of ginkgo as an add-on therapy, and assessment using standardized rating scales to measure the state of psychopathology for negative and total symptoms of schizophrenia. Additionally, a detailed review was undertaken to investigate if antioxidants are involved in development of psychotic symptoms in schizophrenia. The six studies that fulfilled the selection criteria were constituted of 466 cases on ginkgo and 362 cases on placebo. They all used the Scale for the Assessment of Negative Symptoms (SANS) to measure negative symptoms, and the Scale for the Assessment of Positive Symptoms (SAPS) or the Brief Psychiatric Rating Scale (BPRS) to measure total symptoms. Difference between ginkgo and control groups from their pre- and post-trial scores and its pooled standard deviation were used to compute standardized mean difference (SMD). Ginkgo as an add-on therapy to antipsychotic medication produced statistically significant moderate improvement (SMD=-0.50) in total and negative symptoms of chronic schizophrenia. Ginkgo as add-on therapy ameliorates the symptoms of chronic schizophrenia. The role of antioxidants in pathogenesis of schizophrenia has also been explored.

Direct and indirect effects of paliperidone extended-release tablets on negative symptoms of schizophrenia

Direct and indirect effects of the new psychotropic paliperidone extended-release (paliperidone ER) tablets on negative symptom improvement in schizophrenia were investigated using path analysis. A post hoc analysis of pooled data from three 6-week, double-blind, placebo-controlled studies of paliperidone ER in patients experiencing acute exacerbation was conducted. Regression analysis explored relationships between baseline/study characteristics and negative symptoms. Change in Positive and Negative Syndrome Scale (PANSS) negative factor score at endpoint was the dependent variable; explanatory variables included demographic and clinical characteristics. Path analysis determined direct and indirect effects of treatment on negative symptom change. Indirect mediators of negative symptom change in the model included changes in positive symptoms, anxiety/depression symptoms and movement disorders. Path analysis indicated that up to 33% of negative symptom improvement was a direct treatment effect. Indirect effects on negative symptoms were mediated through changes in positive symptoms (51%) and anxiety/depression symptoms (18%), whereas changes in movement disorders had a 2.1% inverse effect. Path analysis indicated that paliperidone ER has a direct effect on negative symptoms. Negative symptom improvement also was indirectly mediated via changes in positive and depressive symptoms.

Pharmacological treatment of primary negative symptoms in schizophrenia: a systematic review

BACKGROUND

Optimal treatment of primary negative symptoms is important because their presence is associated with poor outcome.

AIMS

To systematically review all studies dealing with the efficacy of pharmacological agents on primary negative symptoms.

METHOD

A comprehensive search of the relevant literature was undertaken using electronic database, reference lists and personal contact.

RESULTS

There is a lack of standardized research designs. Amisulpride is the most extensively studied drug with respect to efficacy against primary negative symptoms. At low doses it demonstrates a consistent, modest effect compared to placebo, though not to conventional antipsychotics and has yet to be tested against other atypicals. Evidence from multiple studies that used simple statistical analyses and inclusion criteria for patients with primary negative symptoms does not support a direct effect for clozapine. Path-analysis studies support the direct effects of risperidone, olanzapine, sertindole and aripiprazole, however, different statistical analyses of the same risperidone study produced conflicting results and the direct effects of olanzapine were not confirmed in selected patients with primary negative symptoms. There are no studies supporting the use of ziprasidone or quetiapine. The effects of typical antipsychotics on primary negative symptoms are inconclusive and likely to depend on drug dosages. Selective serotonin reuptake inhibitors (SSRIs), mirtazepine and NMDA agonists show early promise but require further study. Novel agents such as selegiline, naltrexone, dehydroepiandrosterone, galantamine, Ginkgo, nitric oxide, L-deprenyl and pergolide show positive effects on general negative symptoms but remain untested against primary negative symptoms.

CONCLUSIONS

Further studies using standardized selective inclusion criteria and controlling for chronicity are needed. Research guidelines are discussed.

Review of the evidence for the long-term efficacy of atypical antipsychotic agents in the treatment of patients with schizophrenia and related psychoses

In schizophrenia, the objectives of long-term maintenance therapy are to achieve continuous relief from psychotic symptoms, to prevent relapse, to optimize patient functioning and improve quality of life. It is now generally accepted that atypical antipsychotic agents are more effective than conventional agents in achieving these goals over the short term. In order to define the role of atypical antipsychotics as maintenance treatment for schizophrenia, studies published between January 1994 and November 2005 that evaluated the long-term efficacy (> or =1 year) of atypical antipsychotics for the treatment of schizophrenia were reviewed as identified from literature researches using MEDLINE and EMBASE. The primary research parameters were 'atypical', 'antipsychotic', 'schizophrenia', 'relapse', 'long-term', 'maintenance' and 'efficacy'. Aspects of safety were also considered for these agents. Results from these long-term studies consistently demonstrated that atypical antipsychotics have substantial advantages over oral conventional antipsychotics as proven by fewer relapses, more effective symptom control and a lower incidence of movement disorders, although some atypical agents were associated with a higher incidence of weight gain. However, due to issues of compliance, the clinical advantage of oral atypical antipsychotics has often been limited. As such, the use of long-acting preparations of atypical antipsychotics, which provide consistent and sustained drug coverage, warrants further investigation for the successful long-term management of patients with schizophrenia.

Symptom domains of schizophrenia: the role of atypical antipsychotic agents

Given their more obvious presentation, the reduction of positive symptoms and their associated behavioural problems have been considered the most important treatment outcome parameter in patients with schizophrenia. However, the development of the atypical antipsychotic agents in the early 1990s resulted in the adoption of more wide-reaching measures of therapeutic outcome. The aim of this review was to evaluate the efficacy of currently available atypical agents across multiple symptom domains of schizophrenia with a specific focus on negative symptoms, neurocognition, social functioning, quality of life and insight. As such, studies published between January 1990 and December 2005 that evaluated the clinical efficacy and tolerability of atypical antipsychotics in different symptom domains of schizophrenia were reviewed as identified from literature researches using MEDLINE and Embase. Abstracts and posters presented at key psychiatry and schizophrenia congresses during this period were also reviewed where available in the public domain. Results from the studies identified have consistently demonstrated that atypical antipsychotics have substantial advantages over conventional antipsychotics with a broader spectrum of efficacy across symptomatic domains of schizophrenia as proven by greater improvements in negative symptoms and cognitive function and a beneficial effect on affective symptoms and quality of life. However, their clinical advantages have often been limited by patients' partial compliance with therapy. As such, the development of a long-acting atypical antipsychotic agent may provide a new and valuable treatment option for patients with schizophrenia.

Quetiapine versus olanzapine for the treatment of negative symptoms in patients with schizophrenia

Negative symptoms are considered the most debilitating and refractory aspect of schizophrenia, being associated with poor social, occupational and global outcomes. Conventional antipsychotics have limited efficacy against these symptoms and poor tolerability profiles. Atypical antipsychotics are an alternative treatment, and this 12-week, randomised, flexibly dosed study compared the efficacy, safety and tolerability of quetiapine and olanzapine in this regard. Of the 40 patients who entered the study (32 male; 8 female), 19 were randomised to quetiapine (mean dose 637 mg/day, mean treatment duration 80 days) and 21 to olanzapine (mean dose 16 mg/day, mean treatment duration 78 days). Quetiapine and olanzapine were similarly effective: in each treatment group significant improvements at Week 12 were observed for negative symptom scores on the SANS and the PANSS, and for subscale scores of affective flattening and alogia on the SANS. Both treatments were well tolerated in this patient population, with no worsening of extrapyramidal symptoms in either case. Anxiety and insomnia were the most common adverse events (> or =7% of patients in each group), but were not drug-related. Although this is a small study with limited power, the results support the effectiveness of quetiapine and olanzapine in treating the negative symptoms of schizophrenia.

Treatments for schizophrenia: a critical review of pharmacology and mechanisms of action of antipsychotic drugs

The treatment of schizophrenia has evolved over the past half century primarily in the context of antipsychotic drug development. Although there has been significant progress resulting in the availability and use of numerous medications, these reflect three basic classes of medications (conventional (typical), atypical and dopamine partial agonist antipsychotics) all of which, despite working by varying mechanisms of actions, act principally on dopamine systems. Many of the second-generation (atypical and dopamine partial agonist) antipsychotics are believed to offer advantages over first-generation agents in the treatment for schizophrenia. However, the pharmacological properties that confer the different therapeutic effects of the new generation of antipsychotic drugs have remained elusive, and certain side effects can still impact patient health and quality of life. Moreover, the efficacy of antipsychotic drugs is limited prompting the clinical use of adjunctive pharmacy to augment the effects of treatment. In addition, the search for novel and nondopaminergic antipsychotic drugs has not been successful to date, though numerous development strategies continue to be pursued, guided by various pathophysiologic hypotheses. This article provides a brief review and critique of the current therapeutic armamentarium for treating schizophrenia and drug development strategies and theories of mechanisms of action of antipsychotics, and focuses on novel targets for therapeutic agents for future drug development.

Management of the negative symptoms of schizophrenia: new treatment options

This article presents a systematic review of pharmacological treatment for negative symptoms of schizophrenia, based on MEDLINE searches from 1995 to September 2002 to identify pertinent clinical trials. The pharmacotherapy of negative symptoms in schizophrenia includes novel/atypical antipsychotics and classical antipsychotics, as well as antidepressants, glutamatergic compounds, antiepileptic drugs and estrogens. In the assessment of therapy for negative symptoms of schizophrenia, it is imperative that better studies of sound methodology are performed. In such studies, some important aspects to be considered include an accurate definition and assessment of negative symptoms (including well designed, valid and reliable rating scales), the differentiation between primary and secondary negative symptoms, an appropriate selection of standard comparators, adequate dosages of comparators (e.g. haloperidol dosages) and an overall optimal study design. Most of the available studies on treating negative symptoms in schizophrenia have focused on the atypical antipsychotics, while other potential candidates, mostly in the context of add-on therapy, have not been so intensively investigated. Atypical antipsychotics have been proven in placebo-controlled trials to be effective in treating negative symptoms of acute schizophrenic episodes. In many of the comparator studies, they showed efficacy in treating negative symptoms that was superior to that of typical antipsychotics. Data on stable, predominant negative symptoms in subchronic or chronic cases of schizophrenia, although limited, have demonstrated the efficacy of atypical antipsychotics. If the beneficial tolerability profile with respect to extrapyramidal symptoms is also taken into account during clinical decision making, the atypical antipsychotics should be preferred for the treatment of negative symptoms. It is also worth noting that the traditional antipsychotics have the risk of inducing negative symptoms in the context of akinesia. The benefits of add-on therapy with SSRIs or a glutamatergic compound are well documented. Estrogen add-on therapy seems promising. Other traditionally suggested approaches, such as comedication with an antiepileptic drug, lithium or beta-adrenoceptor antagonist, cannot generally be recommended on the basis of the available data.

Extrapyramidal symptom profiles in Japanese patients with schizophrenia treated with olanzapine or haloperidol

Previous clinical trials have clearly shown the superiority of olanzapine to haloperidol in the improvement of extrapyramidal symptoms (EPS) in schizophrenic patients. The primary purpose of this study was to compare EPS profiles in Japanese schizophrenic patients treated with an atypical antipsychotic, olanzapine, or a typical antipsychotic, haloperidol, as measured by the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). The DIEPSS, which consists of eight individual parameters and one global assessment (overall severity), was used to evaluate 182 patients enrolled in this 8-week study. The primary safety analysis was maximum change (that could be either a decrease or increase) from baseline in DIEPSS total score. Secondary analyses included change from baseline to maximum in DIEPSS total score, change from baseline to endpoint (LOCF) in DIEPSS total score, and the rank sum of the maximum change (that could be either a decrease or increase) from baseline in the DIEPSS individual items. Incidence of treatment-emergent EPS adverse events using the DIEPSS scale was also analyzed. The olanzapine group showed statistically significant superiority to the haloperidol group on the primary analysis (p<0.001). Secondary analyses also demonstrated olanzapine's superiority in DIEPSS total, parkinsonism, akathisia and overall severity scores (all p< or =0.014). Categorical analysis of treatment-emergent akathisia and parkinsonism syndromes at endpoint showed improvement in the olanzapine group but worsening in the haloperidol group. The results from this study suggest that olanzapine, as in Caucasian populations, is a safe treatment in Japanese patients chronically ill with schizophrenia.

A double-blind, randomised comparative trial of amisulpride versus olanzapine in the treatment of schizophrenia: short-term results at two months

OBJECTIVE

To compare the efficacy and safety of the atypical antipsychotics amisulpride and olanzapine in the treatment of acute psychotic exacerbations of schizophrenia.

DESIGN AND SETTING

A multinational, double-blind randomised clinical trial.

PATIENTS AND TREATMENT

Three hundred and seventy-seven patients with predominantly positive symptomatology were treated for six months with either amisulpride (200-800 mg/d) or olanzapine (5-20 mg/d).

MAIN OUTCOME MEASURES

Short-term results were analysed after two months of treatment. The primary efficacy measure was the change of score on the Brief Psychiatric Rating Scale (BPRS). Other measures of efficacy and safety were also evaluated.

RESULTS

Psychotic symptoms, as measured on the BPRS score, improved with both treatments, amisulpride being equivalent to olanzapine. All BPRS factor scores, as well as depressive symptoms, improved to a similar extent with both treatments. Less than five per cent of patients withdrew for adverse events, and there was no evidence for the emergence of extrapyramidal symptoms with either treatment. Statistically significant greater weight gain (2.7 +/- 3.9 kg) was observed during the study in the olanzapine group, compared with the amisulpride group (0.9 +/- 3.2 kg, p < 0.0001).

CONCLUSIONS

Amisulpride and olanzapine show equivalent efficacy at 2 months in the treatment of acute psychotic exacerbations of schizophrenia. Amisulpride offers a significant advantage in preserving body weight.

Zotepine in the treatment of acute hospitalized schizophrenic episodes

The atypical antipsychotic zotepine was studied in an open, multicentre uncontrolled, post-marketing surveillance study in 108 schizophrenic patients hospitalized in 12 trial centres in Austria. Within the dosage range of 50-450 mg (mean at the end of the study, 207 +/- 125 mg/day), a significant reduction of positive as well as negative symptoms was noted. There was no increase in extrapyramidal side-effects during the study and a significant decrease in akathisia scores. The medication was well tolerated during the 42-day observation period. Zotepine improved both positive and negative symptoms and was not accompanied by extrapyramidal side-effects, justifying its classification as an atypical antipsychotic.

State of the art of drug treatment of schizophrenia and the future position of the novel/atypical antipsychotics

Neuroleptic medication is the most important part of the treatment regimen for schizophrenic patients. The efficacy of neuroleptics in the acute and long-term treatment of schizophrenia is very well proven and the effect size is comparatively high. After more than 40 years of clinical practice with the classical neuroleptics, several more or less generally accepted rules for the management of drug treatment in schizophrenia have been established. The paper aims to describe these standards, discussing, among other things, developments which have appeared in the last 10 to 20 years, e.g. the tendency to a lower daily dose during acute treatment and the tendency to alternative strategies during long-term treatment. The paper especially also takes into consideration the benefits of the novel/atypical antipsychotics as compared to the classical neuroleptics, which will change the current treatment standards under several aspects--a change which is already ongoing. The novel/atypical antipsychotics will be much better accepted by patients, thus leading to increased compliance, will be associated with a better quality of life and will possibly change the long-term outcome of schizophrenic patients in a very important manner. It should be considered that the so-called novel/atypical neuroleptics do not constitute a homogeneous group but are a group of individual drugs, each with their own advantages and disadvantages. As was the situation with the classical neuroleptics, the physician also has to choose the most adequate drug under consideration of the risk/benefit profile of each drug in relation to the disposition of the individual patient.

Clozapine and negative symptoms. An open study

1. Clozapine, the first atypical antipsychotic, has demonstrated an efficacy in the treatment of resistant schizophrenia. But one of the major challenge in the treatment of schizophrenia remains the lack of efficacy of antipsychotics on negative symptoms of schizophrenia. 2. The authors studied the efficacy of clozapine in an open study in a population of 51 patients, who met the DSM IV criteria for schizophrenia. Using the positive and negative symptom scale (P.A.N.S.S.), and the Extra Pyramidal Symptoms Rating Scale (E.S.R.S.), we try to identify the specificity of the action of clozapine on the different symptomatic dimensions of schizophrenia. 3. The efficacy of clozapine was clinically significant on the negative symptomatology but was delayed compared to the efficacy on the other dimensions of symptomatology evaluated using the PANSS. 4. Nine patients, were considered as deficit patients; in this sample clozapine also demonstrated a significant efficacy on negative symptoms. The efficacy of clozapine did not seem to be a consequence of the better neurological tolerance of this antipsychotic evaluated with ESRS.

Amisulpride vs. risperidone in the treatment of acute exacerbations of schizophrenia. Amisulpride study group

Amisulpride, a substituted benzamide with high selectivity for dopamine D3 and D2 receptors, was compared with the antipsychotic risperidone in patients with acute exacerbations of schizophrenia. The study was double-blind and involved 228 patients allocated, after a 3-6-day wash-out period, to amisulpride 800 mg (n = 115) or risperidone 8 mg (n = 113) for 8 weeks. Both treatments produced a marked improvement in schizophrenic symptomatology. Decreases in mean BPRS total score were 17.7 +/- 14.9 for amisulpride and 15.2 +/- 13.9 for risperidone, and all of the individual factors on the BPRS showed a numerically greater improvement in the amisulpride than in the risperidone patients. Both treatments were equally effective against positive symptoms on the PANSS positive syndrome subscale; however, there was a trend in favor of greater improvement in negative symptoms assessed on the PANSS negative subscale in patients receiving amisulpride with a decrease of 6.9 +/- 7.5 vs. 5.3 +/- 6.6 for risperidone (P = 0.09). Both drugs demonstrated good safety profiles, and scores on neurological scales (SAS, AIMS, and BAS) did not increase during treatment. A comparable proportion of patients received antiparkinsonian medication, 30 and 23% in the amisulpride and risperidone groups, respectively (P = 0.21). Patients receiving risperidone experienced an increase in body weight, which was significantly greater than for amisulpride (P = 0.026).

The cerebral cortex: a case for a common site of action of antipsychotics

Recent evidence from studies of receptor occupancy and regulation in post-mortem brains of patients with neuropsychiatric disorders and in non-human primates is providing new leads in the ongoing quest to understand the pathophysiology and causes of schizophrenia and to develop more effective methods of treatment. These studies suggest that the cerebral cortex may harbour the elusive common sites of action of antipsychotic medications and indicate that chronic treatment with these drugs differentially regulates both families of dopamine receptors in this structure. Upregulation of the cortical dopamine D2 receptors is accompanied by a downregulation of the D1 sites. Balancing the opposing actions of dopamine D1 and D2 receptor regulation may hold the key to optimal drug therapy and to understanding the pathophysiology of schizophrenia. In this article, Michael Lidow, Graham Williams and Patricia Goldman-Rakic review the evidence supporting the cerebral cortex as a pivotal site for these mechanisms underlying the action of antipsychotics.

Olanzapine. A review of its pharmacological properties and therapeutic efficacy in the management of schizophrenia and related psychoses

Olanzapine is a thienobenzodiazepine derivative which displays efficacy in patients with schizophrenia and related psychoses. It has structural and pharmacological properties resembling those of the atypical antipsychotic clozapine and an improved tolerability profile compared with the classical antipsychotic haloperidol. In several large, well controlled trials in patients with schizophrenia or related psychoses, olanzapine generally 5 to 20 mg/day was at least as effective as haloperidol (5 to 20mg) and more so than placebo, as assessed by overall rating scales for psychoses. Olanzapine improved negative symptoms to a greater extent than haloperidol in 2 of 3 comparative trials, including the largest trial. Efficacy of olanzapine has a rapid onset (within 1 to 2 weeks). Its clinical benefits appear to be maintained for treatment periods of up to 1 year, as shown by analysis of the extension phase of several trials demonstrating decreased probability of hospitalisation over this period compared with haloperidol. Preliminary data suggest the drug may also improve quality of life. Olanzapine was associated with significantly fewer adverse movement disorders (e.g. akathisia, dystonia, hypertonia, extrapyramidal symptoms) than haloperidol. There have been no reports of agranulocytosis (as occurs with clozapine) or any other haemotoxicity attributed to olanzapine, and the drug has shown minimal effect on prolactin levels. Transient increases in levels of hepatic transaminases seem to be clinically important. The only events recorded more frequently during olanzapine than during haloperidol therapy were weight gain, dry mouth and increased appetite. Although the antipsychotic activity of olanzapine has been well demonstrated. Its efficacy in refractory schizophrenia and its place relative to other atypical antipsychotics remain to be determined. Nevertheless, if the long term tolerability profile of olanzapine is confirmed, the drug should provide a valuable therapeutic alternative in the management of schizophrenia and related psychoses.

Statistical differentiation between direct and indirect effects of neuroleptics on negative symptoms

The differentiation between primary and secondary negative symptoms in schizophrenia (Carpenter et al. 1985) is an important issue. Path analysis allows to estimate statistically whether, and in which degree, the effect of a neuroleptic on negative symptoms is mediated by effects on positive, extrapyramidal, and depressive symptoms (Möller et al. 1995). If certain causal relationships are theoretically assumed-as proposed by Carpenter et al. (1985)-then path analysis can be applied to estimate the quantitative degree of these relationships, although the causal directions cannot be inferred from path analysis itself. Especially it can be estimated whether there is sufficient evidence for a "direct effect" of neuroleptic treatment on (primary) negative symptoms, an effect which is not mediated by positive, extrapyramidal, and/or depressive symptoms. We show the correspondence between the applied path model and several simple regression equations which can be estimated with standard statistical software. Moreover, we report some Monte Carlo studies showing that the results reported by Möller et al. (1995)-a "direct effect" of risperidone (6 mg) on negative symptoms compared with haloperidol (20 mg)-cannot be explained by a path model in which, everything else being equal, positive symptoms depend on negative symptoms instead of the other way around.

Review: treatment of schizophrenia. State of the art

As a result of the multifactorial etiopathology of schizophrenia, a treatment strategy combining drug therapy with psychosocial measures is indicated. Depending on the stage of the disease and on the individual condition of the patient, the accent is set alternatively more on one approach or on the other. However, under aspects of symptom reduction and relapse prophylaxis, the therapy with neuroleptics plays the most important role. In order to keep their side effects to a minimum during acute and long term treatment, there is nowadays a trend towards administration of the lowest possible dose. Under this aspect, the use of so called atypical neuroleptics should be taken into consideration. The treatment of negative symptoms, especially in the context of chronic residual syndrome, is still a problem which hasn't been solved to satisfaction. Beside the use of atypical neuroleptics, treatment with antidepressives should be tried. During the long term relapse prophylactic treatment, it is important that not only the criterion "reduction of the relapse rate" but also that of individual risk/benefit relation be considered. Concerning psychosocial therapies, especially focused behavioural therapy approaches, for example educational programs and specific family therapeutical intervention following the high-EE-concept, as well as training of social and cognitive competences have proved useful beside supportive psychotherapy and the whole range of sociotherapeutical measures. However they need further evaluation before they get integrated in routine treatment.

The negative component in schizophrenia

Many conflicts in the literature about negative symptoms arise because different authors use different definitions of negative symptoms. If narrow definitions are used, it appears that drugs have little effect against negative symptoms, although those who use broader definitions tend to conclude that negative symptoms do respond to drugs. Another complication is that negative symptoms may be secondary to other causes, such as psychotic symptoms, the side effects of drugs, depression and understimulation as a result of hospitalisation. Attempting to measure drug effects on negative symptoms can be complicated by such factors as different co-medication in the test and control groups and different pharmacological profiles of test and standard drugs, in particular in terms of extrapyramidal side effects or antidepressant effects. Several approaches to dissecting the direct effect of drugs from their indirect effects on negative symptoms have included analyses of covariance, regression analyses and path analyses. Applying path analysis to the data from the North American clinical trial of risperidone suggests that a significant component of the advantageous effect of risperidone on negative symptoms, compared with haloperidol, is due to a direct effect that cannot be accounted for by the effect of risperidone on positive symptoms and its superior side-effect profile. Although it is possible to analyse studies retrospectively in this way, the best approach is probably to design future clinical trials so that the effects of drugs on negative symptoms are more easily determined than has been the case in the past.

A path-analytical approach to differentiate between direct and indirect drug effects on negative symptoms in schizophrenic patients. A re-evaluation of the North American risperidone study

The hypothesis that differences in drug effects of risperidone and haloperidol on negative symptoms in schizophrenia are secondary to effects on positive, extrapyramidal, and depressive symptoms was investigated by means of an analysis of the data from the USA-Canada risperidone double-blind randomized clinical trial of 523 chronic schizophrenic patients. Regression analyses in the total sample and within treatment groups confirmed a strong relationship between changes in negative symptoms and the other variables studied (R2 = 0.50-0.51, p < 0.001). Only depressive symptoms did not contribute significantly to these results (p > 0.10). Path analysis showed that the greater mean change (p < 0.05) of negative symptoms with risperidone compared to haloperidol could not be fully explained by correlations with favourable effects on positive and extrapyramidal symptoms. The relationship between shift in extrapyramidal symptoms and shift in negative symptoms failed to reach statistical significance; however, there was a clear tendency in the expected direction in both treatment groups.

Negative symptoms in schizophrenia: considerations for clinical trials. Working group on negative symptoms in schizophrenia

There is little agreement about the methodology of clinical trials of antipsychotic drugs in patients with negative symptoms. A literature review revealed wide variation in experimental design, rating scales and study duration. This reflects differing views as to the definition and response to treatment of negative symptoms. Some degree of standardization would improve comparability of studies and aid the development of new compounds. Patients included in such studies should have displayed negative symptoms for at least 6 months. Depressive symptoms, positive schizophrenic symptoms and extrapyramidal signs may all influence or be confused with negative symptoms and may respond to treatment; they should be at a low level at baseline and should be measured during the study period. Studies should last at least 8 weeks. Several scales are available for measuring negative symptoms and are reviewed; a global impression score should be used additionally.

Neuroleptics and the neuroleptic-induced deficit syndrome

The first central pharmacodynamic action of chlorpromazine to be described was sedation without narcosis. The antipsychotic action and extrapyramidal symptoms were observed later. Sedation can be separated into nonspecific sedation (drowsiness, somnolence) and specific sedation (psychomotor inhibition and psychic indifference). Both types are parts of the clinical profiles of classical neuroleptics. The sedative properties of neuroleptics may contribute to the overall efficacy in the treatment of psychotic patients, depending on the clinical situation. In most patients, however, sedation is only needed for a short period, or not at all. The drug induced sedation may adversely affect the patients' well-being and functional capabilities. The term neuroleptic-induced deficit syndrome (NIDS) has been coined to focus attention on the adverse mental effects of neuroleptics. NIDS still needs to be properly defined and to be differentiated from the deficit syndrome of schizophrenia and postpsychotic depression. Assessment methods are needed to establish the incidence and prevalence of NIDS, to evaluate the importance of NIDS in the overall treatment outcome in psychoses and to facilitate development of better antipsychotic agents.

L-sulpiride in young and elderly negative schizophrenics: clinical and pharmacokinetic variables

1. Clinical activity, tolerability and kinetic profile of L-sulpiride (200-300 mg/die p.o.) in relation to age, in 14 chronic schizophrenic in patients diagnosed according to DSM III-R, typed as negative forms, were studied. 2. The drug showed its efficacy in negative forms of schizophrenia, without any significant difference between negative and positive symptoms even if productive symptom scores were quite low already in pre-treatment condition. 3. No more side effects (anticholinergic and extrapyramidal) in elderly patients compared to young/adult ones were reported. 4. No significant differences between young/adult and elderly patients for the various pharmacokinetic parameters (t1/2, AUC, Cmax, Tmax, Vd and Cl), after acute and multiple dosing, were observed.