Definition, psychopharmacological basis and clinical evaluation of novel/atypical neuroleptics: methodological issues and clinical consequences

Antipsychotic agents. Gradually improving treatment from the traditional oral neuroleptics to the first atypical depot

Relapse is one of the key factors in the long-term outcome of schizophrenia. The consequences of relapse are diverse and often unpredictable, and the time to recovery and degree of recovery worsen with each successive relapse. There is now overwhelming evidence that advances in antipsychotic drug treatment have led to significant reductions in the rate of relapse. This review charts the developments that have taken place in antipsychotic therapy from the introduction of depot formulations, through atypical agents, to the development of the first long-acting atypical antipsychotic. Depot formulations of conventional antipsychotics were developed in the 1960s and led to fewer relapses and episodes of hospitalization, compared with oral equivalents. Meta-analysis has confirmed that patients receiving depot antipsychotics experience significantly greater global improvement than those receiving the respective oral agents. Conventional antipsychotics are, however, associated with a range of potentially serious adverse events. The atypical antipsychotics were introduced in the 1990s and have significant advantages over conventional agents with regard to positive and negative symptoms. There is also evidence that atypical agents can reduce the risk of relapse. Importantly, atypical antipsychotics have an improved safety profile compared with older agents, particularly with regard to extrapyramidal symptoms. One disadvantage of atypical agents has been that they are only available in an oral form. The recent development of a long-acting injectable formulation of risperidone means that a new treatment option is available to physicians.

Higher than recommended dosages of antipsychotics in male patients with schizophrenia are associated with increased depression but no major neurocognitive side effects: Results of a cross-sectional pilot naturalistic study

INTRODUCTION

The current small pilot naturalistic cross-sectional study assesses whether higher dosages of antipsychotics are related to a satisfactory outcome concerning symptoms of schizophrenia but also to a worse outcome in terms of adverse events and neurocognitive function.

MATERIAL AND METHODS

41 male stabilized hospitalized schizophrenic patients were assessed by PANSS, Calgary Depression Rating Scale, UKU and Simpson-Angus Scale and a battery of neurocognitive tests. Medication and dosage was prescribed according to clinical judgement of the therapist.

RESULTS

Clinical variables and adverse events did not differ between patients in the recommended vs high dosage groups. Higher dosage correlated with depressive symptoms but there was no correlation with neurocognitive measures except for impaired concentration.

DISCUSSION

Results suggest that it is possible to achieve a good clinical response in refractory patients by exceeding recommended antipsychotic dosages at the price of depression and possible mild isolated concentration deficits but not other neurocognitive or extrapyramidal adverse events. Currently clinicians prefer first-generation antipsychotics when high dosages are prescribed, but considering the more favorable adverse effects profile of newer agents, it is important to study higher dosages of these agents and to test whether they should be preferably given when high dosages are necessary.

ADN-1184, a monoaminergic ligand with 5-HT6/7 receptor antagonist action, exhibits activity in animal models of anxiety

Behavioral and psychological symptoms of dementia (BPSD) include apathy, sleep problems, irritability, wandering, elation, agitation/aggression, and mood disorders such as depression and/or anxiety. Elderly patients are usually treated with second-generation antipsychotics; however, they present not enough efficacy against all symptoms observed. Hence, there still is an unmet need for novel pharmacotherapeutic agents targeted BPSD. A novel arylsulfonamide derivative ADN-1184 has been developed that possesses a preclinical profile of activity corresponding to criteria required for treatment of both psychosis and depressive symptoms of BPSD without exacerbating cognitive impairment or inducing motor disturbances. To broaden its pharmacological efficacy toward anxiety symptoms, its anxiolytic properties have been examined in common animal preclinical models in rats and mice. ADN-1184 significantly increased the number of entries into open arms measured in the elevated plus-maze test; however, it simultaneously increased parameters of exploratory activity. In the Vogel conflict drinking test, ADN-1184 dose-dependently and significantly increased the number of shocks accepted and the number of licks. Moreover, in mice, it also had specific anxiolytic-like activity in the four-plate test, and only negligible one at a specific mid-range dose measured in the spontaneous marble burying test. The obtained findings reveal that ADN-1184 displays anxiolytic-like activity in animal models of anxiety which employed punished stimuli. In its unusual combination of some anxiolytic action with already proven antipsychotic and antidepressant properties, and lack of any disruptive impact on learning and memory processes and motor coordination, ADN-1184 displays a profile that would be desired for a novel therapeutic for BPSD.

Overdose of atypical antipsychotics: clinical presentation, mechanisms of toxicity and management

Historically, treatment for schizophrenia focused on sedation. The advent of the typical antipsychotics resulted in treatment aimed specifically at the underlying disease, but these agents were associated with numerous adverse effects, and were not particularly effective at treatment of the negative symptoms of schizophrenia. As a result, numerous atypical agents have been developed over the past 2 decades, including several agents within the past 5 years. Overdose of antipsychotics remains quite common in Western society. In 2010, poison control centres in the US received nearly 43,000 calls related to atypical antipsychotics alone. Due to underreporting, the true incidence of overdose with atypical antipsychotics is likely much greater. Following overdose of an atypical antipsychotic, the clinical effects observed, such as CNS depression, tachycardia and orthostasis are largely predictable based on the unique receptor binding profile of the agent. This article, which focuses on the atypical antipsychotics commonly used in the treatment of schizophrenia, discusses the features commonly encountered in overdose. Specifically, agents that result in QT prolongation and the corresponding potential for torsades de pointes, as well as unique features encountered with the various medications are discussed. The diagnosis of this overdose is largely based on history. Routine use of drug screens is unlikely to be beneficial. The primary goal of management is aggressive supportive care. Patients with significant CNS depression with associated loss of airway reflexes and respiratory failure need advanced airway management. Hypotension should be treated first with intravenous fluids, with the use of direct acting vasopressors reserved for persistent hypotension. Benzodiazepines should be used for seizures, with barbiturates used for refractory seizures. Intravenous magnesium can be administered for patients with a corrected QT interval exceeding 500 milliseconds.

The relationship between prepulse inhibition and general psychopathology in patients with schizophrenia treated with long-acting risperidone

Patients with schizophrenia exhibit impairments in prepulse inhibition (PPI) of the startle response. Available data suggest that atypical antipsychotics may be more effective than typical antipsychotics in improving PPI deficits in schizophrenia. However, previous studies have used between-subjects rather than longitudinal within-subjects designs to demonstrate superiority of particular atypical antipsychotics over typical antipsychotics in improving PPI in patients with schizophrenia. This longitudinal within-subjects test-retest study was designed to evaluate changes in PPI and clinical symptoms in patients with schizophrenia after switching from the conventional antipsychotic zuclopenthixol to long-acting injectable risperidone. PPI was measured in 45 chronic male patients with schizophrenia treated with zuclophentixol depot (session T1), and 12 weeks after switching to long-acting injectable risperidone (session T2). Thirty-six healthy control subjects were also evaluated. Patients with schizophrenia showed a significant improvement in PPI after changing to long-acting risperidone. Improvement of PPI deficits between T1 and T2 assessments correlated significantly with improvements in PANSS general psychopathology subscale scores. Our findings indicate that long-acting risperidone improves PPI deficits in subjects with chronic schizophrenia. These results also suggest that the PPI-restoring effect of risperidone may be related to improvement in symptoms other than positive and negative symptoms.

Novel Antipsychotics in the Long-term Treatment of Schizophrenia

Schizophrenia still has a poorer outcome than other affective disorders. One possible way to improve the long-term outcome of schizophrenic patients is to optimise long-term treatment with the aim of minimising the number of relapses and reducing residual symptoms. Atypical antipsychotics have various advantages over atypical neuroleptics. The first depot formulation of an atypical neuroleptic appears to be a further positive step to improve the possibilities of an optimal long-term treatment for schizophrenia.

Short-term treatment with risperidone or haloperidol in first-episode schizophrenia: 8-week results of a randomized controlled trial within the German Research Network on Schizophrenia

Patients with first-episode schizophrenia appear to respond to lower doses of neuroleptics, and to be more sensitive to developing extrapyramidal side-effects. The authors therefore compared in such patients the efficacy and extrapyramidal tolerability of comparatively low dosages of the atypical neuroleptic risperidone and of the conventional neuroleptic haloperidol. Risperidone was hypothesized to have better extrapyramidal tolerability and efficacy in treating negative symptoms. Patients were randomly assigned under double-blind conditions to receive risperidone (n=143) or haloperidol (n=146) for 8 wk. The primary efficacy criterion was the estimated difference in the mean change in the Positive and Negative Symptom Scale (PANSS) negative score between treatment groups; secondary efficacy criteria were changes on the PANSS total score and other PANSS subscores, and several other measures of psychopathology and general functioning. The primary tolerability criterion was the difference in baseline-adjusted occurrence rates of extrapyramidal side-effects measured with the Simpson-Angus Scale (SAS) compared between treatment groups. The main hypothesis was that risperidone would be superior in terms of improving negative symptoms and lowering the risk of extrapyramidal symptoms. Secondary tolerability criteria were the other extrapyramidal symptoms, measured with the Hillside Akathisia Scale (HAS) and the Abnormal Involuntary Movement Scale (AIMS). The average mean daily doses were 3.8 mg (s.d.=1.5) for risperidone and 3.7 mg (s.d.=1.5) for haloperidol. There were similar, significant improvements in both treatment groups in the primary and secondary efficacy criteria. At week 8 nearly all scores of extrapyramidal side-effects indicated a significantly higher prevalence of extrapyramidal side-effects with haloperidol than with risperidone [SAS: risperidone 36.5% of patients; haloperidol 51.5% of patients; likelihood ratio test, chi2(1)=7.8, p=0.005]. There were significantly fewer drop-outs [risperidone n=55, drop-out rate=38.5%; haloperidol n=79, drop-out rate=54.1%, chi2(1)=7.1, p=0.009] and a longer non-discontinuation time [risperidone: average of 50.8 d to drop-out; haloperidol: average of 44.0 d to drop-out; log rank test, chi2(1)=6.4, p=0.011] in the risperidone group. Risperidone and haloperidol appear to be equally effective in treating negative and other symptoms of first-episode schizophrenia. Risperidone has better extrapyramidal tolerability and treatment retention rate than the equivalent dose of haloperidol in these patients.

Systematic of psychiatric disorders between categorical and dimensional approaches: Kraepelin's dichotomy and beyond

This paper describes basic principles of systematics for psychiatric disorders such as the categorical and dimensional approach. It summarises validity aspects of the traditional psychiatric nosology and syndromatology. The importance and limitations of the dichotomy of schizophrenia and affective disorders, first suggested by Kraepelin, is reviewed in the light of results from modern research in the field of classification, follow-up and neurobiological studies, especially neurochemical, neurogenetic and neuroimaging studies. Current developments towards DSM-V and ICD-11 are critically reflected. The conclusion is reached that there might be insufficient data to establish a new systematics of psychoses. Therefore it might be premature to leave the Kraepelinian dichotomy totally although it has to be modified in the light of new research.

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.

Long-Acting Injectable Risperidone for the Treatment of Schizophrenia

Schizophrenia remains a severe disorder that is associated with a poor outcome in a large subgroup of patients. Major efforts should be made to improve treatment for all patients who have this debilitating disease. Second-generation antipsychotics were a major step forward in this respect; however, important unmet needs remain, such as a better solution for frequent noncompliance problems. Depot formulations are known to have advantages in this respect. However, for a long time, only depot formulations of conventional antipsychotics were available, with their high risk of extrapyramidal adverse effects. Therefore, there has been only very restricted use of depot antipsychotics, which mainly focused on patients with chronic disease who were difficult to treat and had a high risk of noncompliance. The situation may change with the advent of a depot formulation of an atypical antipsychotic. The first depot formulation of an atypical antipsychotic to be introduced to the market is long-acting injectable risperidone. On the basis of the pharmacokinetic properties of the depot formulation, a 2-week interval between administrations is recommended. The antipsychotic efficacy of long-acting risperidone was demonstrated in two 12-week, double-blind, randomised, phase III studies, one versus placebo and the other versus oral risperidone. These two studies, together with one open-label, long-term study over 12 months, belong to the core group of trials that were relevant for the licensing of long-acting risperidone. A relapse-prevention, control group study comparing the long-acting formulation versus oral risperidone was not performed because of the known principal methodological problems of such a comparison. Instead, as much clinical data as possible was collected from observational studies that investigated questions relevant for clinical practice, such as efficacy, safety and tolerability in different subgroups, and transition from pre-treatment with different kinds of antipsychotics to long-acting risperidone. On the basis of these data, it can be stated that the efficacy of the long-term formulation of risperidone is proven, and that the safety and tolerability are more or less comparable to those of oral risperidone. The local tolerability at the injection site is good. Because it is well known that noncompliance is a frequent feature of the treatment of schizophrenia, and considering the advantages of atypical antipsychotics, consideration of whether long-acting atypical antipsychotics should have a broader indication than is the case with the depot formulations of the classical antipsychotics is warranted.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia, part 2: long-term treatment of schizophrenia

These guidelines for the biological treatment of schizophrenia were developed by an international Task Force of the World Federation of Societies of Biological Psychiatry (WFSBP). The goal during the development of these guidelines was to review systematically all available evidence pertaining to the treatment of schizophrenia, and to reach a consensus on a series of practice recommendations that are clinically and scientifically meaningful based on the available evidence. These guidelines are intended for use by all physicians seeing and treating people with schizophrenia. The data used for developing these guidelines have been extracted primarily from various national treatment guidelines and panels for schizophrenia, as well as from meta-analyses, reviews and randomised clinical trials on the efficacy of pharmacological and other biological treatment interventions identified by a search of the MEDLINE database and Cochrane Library. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into four levels of evidence (A-D). This second part of the guidelines covers the long-term treatment as well as the management of relevant side effects. These guidelines are primarily concerned with the biological treatment (including antipsychotic medication, other pharmacological treatment options, electroconvulsive therapy, adjunctive and novel therapeutic strategies) of adults suffering from schizophrenia.

A prospective, multicenter, randomized, parallel-group, open-label study of aripiprazole in the management of patients with schizophrenia or schizoaffective disorder in general psychiatric practice: Broad Effectiveness Trial With Aripiprazole (BETA)

OBJECTIVE

BETA was designed to evaluate the overall effectiveness of aripiprazole in patients with schizophrenia or schizoaffective disorder treated in a general psychiatry outpatient practice setting.

METHODS

In this 8-week, multicenter, open-label study, 1,599 outpatients with schizophrenia or schizoaffective disorder were randomly assigned to receive either aripiprazole (n=1,295) or another antipsychotic medication (safety control [SC] group; n=304). Aripiprazole was initiated at 15 mg/d with the option to adjust between 10-30 mg/d. The SC medication was specifically selected for each patient by the clinician and dosed according to prescribing guidelines for that medication. The primary effectiveness measure was the Clinical Global Impression-Improvement (CGI-I) score of the aripiprazole group at study end point. Secondary measures included response rates and preference of medicine (POM) ratings by patients and caregivers.

RESULTS

Sixty-five percent of aripiprazole patients completed the study. The mean aripiprazole dose at end point was 19.9 mg/d, with approximately 39% of patients starting and remaining at 15 mg/d. At end point, the mean CGI-I score of 2.77 demonstrated that aripiprazole was minimally to moderately effective; the mean CGI-I score for the SC group was 3.59 indicating minimally effective to no change. Fifty-three percent of aripiprazole patients responded to treatment (CGI-I score of 1 or 2; last-observation-carried-forward [LOCF]), and approximately 71% of patients and caregivers rated aripiprazole as better than the prestudy medication on the POM (LOCF). Incidence and severity of adverse events (AEs) were similar to those reported in double-blind, randomized, placebo-controlled aripiprazole clinical trials. The most frequent AE in the aripiprazole group was insomnia (24%).

CONCLUSIONS

Aripiprazole was effective for the treatment of schizophrenia and schizoaffective disorder in a general psychiatry outpatient practice setting. Overall, aripiprazole was found to be effective by the treating clinician and well accepted by patients and caregivers over the 8-week treatment course.

Risperidone: a review

When the risk of agranulocytosis associated with clozapine, the prototype of the second-generation neuroleptics, became apparent, its prescription was restricted to patients refractory to classical neuroleptics such as chlorpromazine and haloperidol. This stimulated the development of several novel second-generation antipsychotics with a clinical profile similar to that of clozapine. These novel antipsychotics, which include risperidone, olanzapine and others, are characterised by different pharmacological structures, and also to a certain degree by different pharmacological mechanisms. Following the increased research on the novel second-generation antipsychotics, it became apparent that they not only have the advantage of better extrapyramidal tolerability than the classical neuroleptics, but also have a broader efficacy spectrum (i.e., advantages in the treatment of negative and depressive symptoms and cognitive disturbances in the context of schizophrenia). Risperidone was specifically designed by Paul Janssen as a combined 5-HT2A and D2 receptor antagonist, thus following the pharmacological mechanism thought to be responsible for the antipsychotic effects of clozapine. After its advent in the 1990s as the first novel second-generation antipsychotic, risperidone achieved worldwide acceptance. The following review gives an overview of the huge clinical database available for risperidone in the field of schizophrenia.

Occurrence and treatment of depressive comorbidity/cosyndromality in schizophrenic psychoses: conceptual and treatment issues

Depressive symptoms are a common feature of schizophrenic disorders, a fact that has become increasingly apparent over the last two decades. Apparently the introduction of standardized rating scales in cross-sectional and longitudinal investigations played an important role in the recognition of the relevance of depressive symptoms. They can be interpreted as being cosyndromal or comorbid, depending on the conceptual perspective applied. This is not simply a difference in terminology but is of great aetiopathogenetic relevance. Of particular clinical relevance is the observation that schizophrenic patients with concomitant depressive symptoms have a greater risk of suicidality or an unfavourable disease course. For this reason it is important that sufficient attention is paid to the diagnosis and treatment of depressive symptoms occurring during schizophrenic psychoses. Besides treatment with antidepressants, modern neuroleptics are of great importance in this context as they are more efficacious than classical neuroleptics in treating depressive symptoms.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia, Part 1: acute treatment of schizophrenia

These guide lines for the biological treatment of schizophrenia were developed by an international Task Force of the World Federation of Societies of Biological Psychiatry (WFSBO). The goal during the development of these guidelines was to review systematically all available evidence pertaining to the treatment of schizophrenia, and to reach a consensus on a series of practice recommendations that are clinically and scientifically meaningful based on the available evidence. These guidelines are intended for use by all physicians seeing and treating people with schizophrenia. The data used for developing these guidelines have been extracted primarily from various national treatment guidelines and panels for schizophrenia, as well as from meta-analyses, reviews and randomised clinical trials on the efficacy of pharmacological and other biological treatment interventions identified by a search of the MEDLINE database and Cochrane Library. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into four levels of evidence (A-D). This first part of the guidelines covers disease definition, classification, epidemiology and course of schizophrenia, as well as the management of the acute phase treatment. These guidelines are primarily concerned with the biological treatment (including antipsychotic medication, other pharmacological treatment options, electroconvulsive therapy, adjunctive and novel therapeutic strategies) of adults suffering from schizophrenia.

Antipsychotic and antidepressive effects of second generation antipsychotics: two different pharmacological mechanisms?

Second generation antipsychotics display antidepressive effects in schizophrenic patients that are more pronounced than those of traditional neuroleptics and that go beyond antidepressive effects secondary to the reduction of positive symptoms. The antidepressive potential of second generation antipsychotics is presumably related to their pharmacological mechanisms, which differ from those of traditional neuroleptics. Among others, 5-HT(2A) antagonism is of special relevance for most of the new antipsychotics in this respect. But also special interactions with the dopaminergic system, as is the case with amisulpride and aripiprazole, or noradrenalin- and/or serotonin-reuptake-inhibition, as with ziprasidone and zotepine, should be considered. It can be summarised that the antipsychotic and antidepressive effects of second generation antipsychotics are mostly based on different pharmacological mechanisms. This might be especially true for direct antidepressive effects, i. e. antidepressive effects that are not mediated by the reduction of positive symptoms.

Antidepressive effects of traditional and second generation antipsychotics: a review of the clinical data

For a long time,in the context of depressive symptoms in schizophrenia traditional neuroleptics were mostly discussed with respect to possible depressiogenic side effects, although some studies argued that they may also have certain antidepressive effects. However, this was not proven at that time in placebo-controlled studies. Placebo-controlled studies performed in recent years have shown that second generation antipsychotics have antidepressive effects which are significantly stronger than those of the traditional neuroleptics. In addition, it was demonstrated that this antidepressive effect can only partially be explained as being secondary to the improvement of positive and negative symptoms, and is apparently predominantly due to a direct (primary) effect on depressive symptoms. It is of special relevance in this context that the antidepressive effect of second generation antipsychotics was recently demonstrated in depression. The positive results from some studies in bipolar depression are especially impressive and underline the antidepressive potencies of novel antipsychotics beyond the spectrum of schizophrenia.

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

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

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.

Amisulpride: limbic specificity and the mechanism of antipsychotic atypicality

Amisulpride clearly has the clinical profile of an atypical antipsychotic, characterised in particular by its lower propensity to induce extrapyramidal side effects as well as its greater efficacy in treating negative symptoms compared with classical neuroleptics. In addition to the clinical advantages over classical neuroleptics, it has also been demonstrated that the clinical profile of amisulpride is comparable to that of other modern atypical neuroleptics. Animal data also allow the conclusion to be drawn that amisulpride has an atypical profile. For example, amisulpride does not provoke catalepsy which is characteristic of postsynaptic D2 blockade in the rat. The induction of catalepsy in animal models is usually seen as an indicator of the propensity to induce extrapyramidal side effects in patients. In relation to the widely accepted hypothesis that the inclusion of 5-HT2A antagonism in addition to D2 antagonism is of great relevance for the atypicality of an antipsychotic, and given the fact that amisulpride lacks 5-HT2A antagonism, the pharmacological explanation of the clinically well-proven atypicality of amisulpride is of great interest. Based on basic research and in vivo imaging studies, two mechanisms in particular seem to explain the atypicality of amisulpride: preferential action on limbic D2/D3 receptors and preferential blockade of presynaptic D2/D3 receptors. In addition, the fast dissociation hypothesis can contribute to the explanation of the atypical clinical profile of amisulpride. The relevance of the D3 blockade in the context of atypicality is not yet completely clear.

Efficacy of risperidone, olanzapine and clozapine in the treatment of therapy resistant schizophrenia

Therapy-resistance for positive symptoms is one of the most important problems that occurs with the medical treatment of schizophrenia. In the past years, clozapine has proven its effectiveness in this area and has been included in the treatment protocols and guidelines. Because of the risk of agranulocytosis with this compound and the intensive laboratory controls to be done, several studies have been performed with the new antipsychotics risperidone and olanzapine as alternative treatments. A review of the literature suggests that both drugs are as effective as the classic antipsychotics for therapy-resistant patients. A switch to risperidone or olanzapine possibly would be a alternative for those patients who have favourable effects on a low dose of clozapine. Furthermore the new antipsychotics have less side effects and ameliorating effects on negative and cognitive symptoms, so contributing to overall improvement in chronic schizophrenic disorders. However, in case of persistent positive symptopathology, clozapine remains the golden standard. The new antipsychotics should be included in treatment protocols before clozapine.

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.