Withdrawal symptoms and rebound syndromes associated with switching and discontinuing atypical antipsychotics: theoretical background and practical recommendations.

With the widespread use of atypical or second-generation antipsychotics, switching treatment has become current practice and more complicated, as the pharmacological profiles of these agents differ substantially despite their similarity in being 'atypical'. All share the ability to block dopamine D2 receptors, and most of them also block serotonin 5-HT2A receptors. Apart from these common features, some atypical antipsychotics are also able to block or stimulate other dopamine or serotonin receptors, as well as histaminergic, muscarinergic or adrenergic receptors. As a result of the varying receptor affinities, in switching or discontinuing compounds several possible pitfalls have to be considered, including the occurrence of withdrawal and rebound syndromes. This article reviews the pharmacological background of functional blockade or stimulation of receptors of interest in regard to atypical antipsychotics and the implicated potential withdrawal and rebound phenomena. A MEDLINE search was carried out to identify information on withdrawal or rebound syndromes occurring after discontinuation of atypical antipsychotics. Using the resulting literature, we first discuss the theoretical background to the functional consequences of atypical antipsychotic-induced blockade or stimulation of neurotransmitter receptors and, secondly, we highlight the clinical consequences of this. We then review the available clinical literature on switching between atypical antipsychotics, with respect to the occurrence of withdrawal or rebound symptoms. Finally, we offer practical recommendations based on the reviewed findings. The systematic evaluation of withdrawal or rebound phenomena using randomized controlled trials is still understudied. Knowledge of pharmacological receptor-binding profiles may help clinicians in choosing adequate switching or discontinuation strategies for each agent. Results from large switching trials indicate that switching atypical antipsychotics can be performed in a safe manner. Treatment-emergent adverse events during or after switching are not always considered to be, at least in part, associated with the pre-switch antipsychotic. Further studies are needed to substantiate the evidence gained so far on different switching strategies. The use of concomitant medication, e.g., benzodiazepines or anticholinergic drugs, may help to minimize symptoms arising from the discontinuation or switching of antipsychotic treatment.

Verbal memory deficits are correlated with prefrontal hypometabolism in (18)FDG PET of recreational MDMA users.

INTRODUCTION: 3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") is a recreational club drug with supposed neurotoxic effects selectively on the serotonin system. MDMA users consistently exhibit memory dysfunction but there is an ongoing debate if these deficits are induced mainly by alterations in the prefrontal or mediotemporal cortex, especially the hippocampus. Thus, we investigated the relation of verbal memory deficits with alterations of regional cerebral brain glucose metabolism (rMRGlu) in recreational MDMA users. METHODS: Brain glucose metabolism in rest was assessed using 2-deoxy-2-((18)F)fluoro-D-glucose positron emission tomography ((18)FDG PET) in 19 male recreational users of MDMA and 19 male drug-naïve controls. (18)FDG PET data were correlated with memory performance assessed with a German version of the Rey Auditory Verbal Learning Test. RESULTS: As previously shown, MDMA users showed significant impairment in verbal declarative memory performance. PET scans revealed significantly decreased rMRGlu in the bilateral dorsolateral prefrontal and inferior parietal cortex, bilateral thalamus, right hippocampus, right precuneus, right cerebellum, and pons (at the level of raphe nuclei) of MDMA users. Among MDMA users, learning and recall were positively correlated with rMRGlu predominantly in bilateral frontal and parietal brain regions, while recognition was additionally related to rMRGlu in the right mediotemporal and bihemispheric lateral temporal cortex. Moreover, cumulative lifetime dose of MDMA was negatively correlated with rMRGlu in the left dorsolateral and bilateral orbital and medial PFC, left inferior parietal and right lateral temporal cortex. CONCLUSIONS: Verbal learning and recall deficits of recreational MDMA users are correlated with glucose hypometabolism in prefrontal and parietal cortex, while word recognition was additionally correlated with mediotemporal hypometabolism. We conclude that memory deficits of MDMA users arise from combined fronto-parieto-mediotemporal dysfunction.

N-acetylaspartylglutamate (NAAG) and N-acetylaspartate (NAA) in patients with schizophrenia.

UNLABELLED: BACKGROUND : Imbalance of glutamatergic neurotransmission has been proposed as a key mechanism underlying symptoms of schizophrenia. The neuropetide N-acetylaspartylglutamate (NAAG) modulates glutamate release. NAAG provides a component of the proton magnetic resonance spectrum (1H-MRS) in humans. The signal of NAAG, however, largely overlaps with its precursor and degrading product N-acetylaspartate (NAA) that by itself does not act in glutamatergic neurotransmission. METHODS: We quantified NAAG and NAA separately from the 1H-MRS signal in 20 patients with schizophrenia and 20 healthy comparison subjects on a 3.0 Tesla MR scanner. The 1H-MRS voxels were positioned in the anterior cingulate cortex (ACC) and in the left frontal lobe. Psychopathological symptoms and cognitive performance were assessed. RESULTS: In the ACC, the ratio NAAG/NAA was increased (P = .041) and NAAG was increased at a trend level (P = .066) in patients, while NAA was reduced (P = .030). NAA correlated with attention performance in patients (r = .64, P = .005) in the ACC. There was no group difference of NAAG, NAA, or NAAG/NAA in the frontal lobe but an inverse correlation of NAAG with negatives symptoms (Positive and Negative Symptoms Scale [PANSS] negative, r = -.58, P = .018) and with the total symptom score (PANSS total, r = -.50, P = .049). In addition, there was a positive correlation of frontal lobe NAAG (r = .53, P = .035) and NAAG/NAA (r = .54, P = .030) with episodic memory in patients. CONCLUSIONS: In this study, we present the first in vivo evidence for altered NAAG concentration in patients with schizophrenia.

The schizophrenia risk allele C of the TCF4 rs9960767 polymorphism disrupts sensorimotor gating in schizophrenia spectrum and healthy volunteers.

In a large-scale meta-analysis, it has been recently shown that the transcription factor 4 (TCF4) gene is among the most prominent susceptibility genes for schizophrenia. Moreover, transgenic mice overexpressing TCF4 in the brain display a reduction of sensorimotor gating measured by prepulse inhibition (PPI) of the acoustic startle response (ASR). PPI is heritable and has been established as an important translational endophenotype of schizophrenia. We therefore investigated the impact of the schizophrenia susceptibility gene TCF4 (rs9960767) on sensorimotor gating of the ASR in healthy humans and in patients with a schizophrenia spectrum disorder. We assessed PPI, startle reactivity, and habituation of the ASR in two independent samples. The first sample consisted of 107 healthy volunteers from London, UK. The second sample was a schizophrenia spectrum group (n = 113) of 73 schizophrenia patients and 40 individuals at high risk for schizophrenia from Bonn, Germany (total sample n = 220). In both samples, PPI was strongly decreased in carriers of the schizophrenia risk allele C of the TCF4 gene (meta-analysis across both samples: p = 0.00002), whereas startle reactivity and habituation were unaffected by TCF4 genotype. Sensorimotor gating is modulated by TCF4 genotype, indicating an influential role of TCF4 gene variations in the development of early information-processing deficits in schizophrenia.

Predictors of response and remission in the acute treatment of first-episode schizophrenia patients--is it all about early response?

BACKGROUND: To evaluate the predictive validity of early response compared to other well-known predictor variables in acutely ill first-episode patients. METHODS: 112 patients were treated with a mean dosage of 4.14 mg (±1.70) haloperidol and 112 patients with a mean dosage of 4.17 mg (±1.55) risperidone for a mean inpatient treatment duration of 42.92 days (±16.85) within a double-blind, randomized controlled trial. Early response was defined as a ≥ 30% improvement in the PANSS total score by week 2, response as a ≥ 50% reduction in the PANSS total score from admission to discharge and remission according to the consensus criteria. Univariate tests and logistic regression models were applied to identify significant predictors of response and remission. RESULTS: 52% of the patients were responders and 59% remitters at discharge. Non-remitters at discharge were hindered from becoming remitters mainly by the presence of negative symptoms. Univariate tests revealed several significant differences between responders/non-responders and remitters/non-remitters such as age, severity of baseline psychopathology as well as the frequency of early response. Both early response (p<0.0001) and a higher PANSS positive subscore at admission (p=0.0002) were identified as significant predictors of response at discharge, whereas a shorter duration of untreated psychosis (p=0.0167), a lower PANSS general psychopathology subscore (p<0.0001), and early treatment response (p=0.0002) were identified as significant predictors of remission. CONCLUSION: Together with the finding that early response is a significant predictor of response and remission, the relevance and predictive validity of negative and depressive symptoms for outcome is also highlighted.

Resting-state perfusion in nonmedicated schizophrenic patients: a continuous arterial spin-labeling 3.0-T MR study.

PURPOSE: To determine whether well-described patterns of altered perfusion in schizophrenia can be identified by using continuous arterial spin labeling (CASL) with a whole-brain imaging sequence. MATERIALS AND METHODS: This study was approved by the ethics committee of the local institutional review board, and written informed consent was obtained from all subjects. CASL was used to compare cerebral perfusion between 11 nonmedicated patients with schizophrenia and 25 healthy control subjects. Since antipsychotic medication may affect perfusion, only drug-free subjects were examined. Resting-state perfusion, as measured in terms of regional cerebral blood flow, was compared voxel wise by using an analysis of variance design in a statistical parametric mapping program, with patient age and sex as covariates. RESULTS: Compared with the healthy control subjects, the schizophrenic patients had extensive areas of hypoperfusion in the frontal lobes bilaterally, in the anterior and medial cingulate gyri, and in the parietal lobes bilaterally. Increased perfusion was observed in the cerebellum, brainstem, and thalamus of the schizophrenic patients as compared with the perfusion in these areas in the control subjects. CONCLUSION: CASL in schizophrenia revealed patterns of hypo- and hyperperfusion similar to the perfusion patterns in previously published positron emission tomographic and single photon emission computed tomographic studies. The advantages of CASL, including independence from injected contrast agents, no irradiation, and fast acquisition time, may facilitate intensive perfusion studies of the early recognition of schizophrenia and other psychiatric disorders, as well as longitudinal disease-monitoring research of these conditions.

Sensorimotor gating is associated with CHRNA3 polymorphisms in schizophrenia and healthy volunteers.

Attentional gating deficits, commonly measured by prepulse inhibition (PPI) of the acoustic startle response (ASR), have been established as an endophenotype of schizophrenia. Prepulse inhibition is heritable and has been associated with polymorphisms in serotonin and dopamine system genes. Prepulse inhibition can be enhanced by nicotine, and therefore it has been proposed that schizophrenia patients smoke to ameliorate their early attentional deficits. The PPI-enhancing effects of nicotine in rodents are strain dependent, suggesting a genetic contribution to PPI within the nicotinic acetylcholine receptor (nAChR) system. Recent human genetic studies also imply that tobacco dependence is affected by polymorphisms in the alpha3/alpha5 subunits of the nAChR (CHRNA3/CHRNA5) gene cluster. We, therefore, investigated the impact of two common CHRNA3 polymorphisms (rs1051730/rs1317286) on PPI, startle reactivity, and habituation of the ASR in two independent samples of 107 healthy British volunteers and 73 schizophrenia patients hailing from Germany. In both samples, PPI was influenced by both CHRNA3 polymorphisms (combined p-value=0.0027), which were strongly linked. Moreover, CHRNA3 genotype was associated with chronicity, treatment, and negative symptoms in the schizophrenia sample. These results suggest that sensorimotor gating is influenced by variations of the CHRNA3 gene, which might also have an impact on the course and severity of schizophrenia.

Quality of life and subjective well-being in schizophrenia and schizophrenia spectrum disorders: valid predictors of symptomatic response and remission?

OBJECTIVES: To examine quality of life and subjective well-being as predictors of symptomatic treatment outcome. METHODS: Biweekly PANSS ratings were performed in 285 inpatients with schizophrenia spectrum disorders within a multicenter trial by the German Research Network on Schizophrenia. Quality of life and subjective well-being were assessed using the Medical Outcomes Study-Short Form 36-Item Health Survey (SF-36), the Subjective Well-being Under Neuroleptic Treatment Scale (SWN-K) and the Adjective Mood Scale (AMS). Response was defined as an initial 20% PANSS total score reduction and remission according to the consensus criteria. Correlation analysis, logistic regression and CART-analysis were performed. RESULTS: In total, 81% of the sample achieved symptom response and 48% symptom remission. The statistical analyses revealed early improvement within the first two treatment weeks in the SWN-K scale to be a significant predictor for symptomatic response. Concerning symptomatic remission the SF-36 and SWN-K baseline scores as well as SWN-K early improvement showed significant predictive value. CONCLUSIONS: These results highlight the importance of the patient's self-perception and especially of early improvement of quality of life and subjective well-being for symptomatic treatment outcome.

A coding variant of the novel serotonin receptor subunit 5-HT3E influences sustained attention in schizophrenia patients.

Sustained attention as measured by the Continuous Performance Test (CPT) has proved a valuable endophenotype for schizophrenia. Recently pharmacological studies suggested a role of the serotonin (5-HT) 3 receptor in schizophrenia. The 5-HT3 receptors are the only ligand-gated ion channels within the 5-HT receptor family. Applying an endophenotype approach, we investigated a potential impact of the genes of the 5-HT3A and 5-HT3B subunits as well as the novel 5-HT3C, 5-HT3D, and 5-HT3E subunits on CPT performance in subjects with schizophrenia. The study included 196 patients with schizophrenia, 113 of their parents, and 205 healthy controls recruited from community registers. Sustained attention was assessed with the Continuous Performance Test-Identical Pairs (CPT-IP). Assessing functional and coding variants of the 5-HT3 receptor subunit genes, we found the GG genotype of the 5-HT3E subunit gene (rs7627615; Thr86Ala) to be associated with better attentional capacities in subjects with schizophrenia and healthy controls. This study provides additional evidence for a role of the serotonergic system and the 5-HT3 receptor in schizophrenia.

DAOA/G72 predicts the progression of prodromal syndromes to first episode psychosis.

The genetic factors determining the progression of prodromal syndromes to first episode schizophrenia have remained enigmatic to date. In a unique prospective multicentre trial, we assessed whether variants at the D-amino acid oxidase activator (DAOA)/G72 locus influence progression to psychosis. Young subjects with a prodromal syndrome were observed prospectively for up to 2 years to assess the incidence of progression to schizophrenia or first episode psychosis. Of the 82 probands with a prodromal syndrome, 21 probands experienced progression to psychosis within the observation period. Assessment of nine common variants in the DAOA/G72 locus yielded two variants with the predictive value for symptom progression: all four probands with the rs1341402 CC genotype developed psychosis compared with 17 out of 78 probands with the TT or CT genotypes (chi(2) = 12.348; df = 2; p = 0.002). The relative risk for progression to psychosis was significantly increased in the CC genotype: RR = 4.588 (95% CI = 2.175-4.588). Similarly, for rs778294, 50% of probands with the AA genotype, but only 22% of probands with a GG or GA genotype progressed to psychosis (chi(2) = 7.027; df = 2; p = 0.030). Moreover, haplotype analysis revealed a susceptibility haplotype for progression to psychosis. This is one of the first studies to identify a specific genetic factor for the progression of prodromal syndromes to schizophrenia, and further underscores the importance of the DAOA/G72 gene for schizophrenia.

Sensorimotor gating of schizophrenia patients depends on Catechol O-methyltransferase Val158Met polymorphism.

It has been recently shown that Catechol O-methyltransferase (COMT) Val(158)Met polymorphism strongly influences prepulse inhibition (PPI) of the acoustic startle response (ASR) in healthy human volunteers. Given that schizophrenia patients exhibit impairment in PPI and that COMT is a putative susceptibility gene for schizophrenia, we investigated the impact of the COMT Val(158)Met polymorphisms on PPI in schizophrenic inpatients. We analyzed COMT Val(158)Met polymorphisms and assessed startle reactivity, habituation, and PPI of ASR in 68 Caucasian schizophrenia inpatients. Clinical symptoms were measured with the Positive and Negative Syndrome Scale (PANSS). Patients carrying the Val(158)Met Met/Met allele showed elevated PPI levels whereas startle reactivity and habituation did not differ from the other two genotypes. These preliminary results imply that PPI is influenced by COMT Val(158)Met genotype in schizophrenia as well. In concert with other findings, our data suggest that PPI is a polygenic trait.

Influence of 5-HT3 receptor subunit genes HTR3A, HTR3B, HTR3C, HTR3D and HTR3E on treatment response to antipsychotics in schizophrenia.

OBJECTIVES: Among serotonin (5-HT) receptors, the 5-HT3 receptor is the only ligand-gated ion channel. 5-HT3 antagonists such as ondansetron and tropisetron may improve auditory gating and neurocognitive deficits in schizophrenic patients. Moreover, many antipsychotic drugs are antagonists at 5-HT3 receptors. However, the role of 5-HT3 receptor variants on response to antipsychotic drugs in schizophrenic patients is still unclear. METHODS: In a prospective, randomized, double-blind study, we have assessed six functional and coding variants of the subunit genes HTR3A, HTR3B as well as the novel HTR3C, HTR3D, and HTR3E subunits in the response to haloperidol or risperidone. Seventy patients were treated for 4 weeks and positive symptoms, negative symptoms, and general psychopathology were measured by the Positive and Negative Syndrome Scale (PANSS). RESULTS: HTR3E had an effect on the speed of response to antipsychotics. GG-allele carriers responded more quickly to treatment on the PANSS negative symptom subscale (P = 0.03) and on the total PANSS score (P = 0.04) irrespective of medication. In a second independent study of 144 schizophrenia patients treated with atypical antipsychotics, this effect could not be confirmed. CONCLUSION: Our findings argue against a major effect of HTR3 variants in response to antipsychotics. Solely, the HTR3E and also the HTR3A variant could exert a weak effect on the speed of response to antipsychotics.

Clozapine: acquittal of the usual suspect.

This report concerns the case of a 29-year-old male patient suffering from severe psychotic illness who had been satisfactorily treated with clozapine for 4 months. Clozapine had also been successfully administered during a psychotic episode 5 years previously. Though symptoms of psychosis were successfully controlled following the most recent psychotic episode, a medical consultation assessed that exacerbation of pancreatitis warranted discontinuation of the current antipsychotic treatment regime. Following a series of unsuccessful courses of neuroleptic medication, a magnetic resonance cholangiopancreaticography (MRCP) revealed marked cholecystolithiasis suggesting a biliary pancreatitis. Clozapine treatment was readministered following cholecystectomy. After 4 weeks of antipsychotic treatment the patient was discharged from hospital on clozapine monotherapy.

Prediction of symptom remission in schizophrenia during inpatient treatment.

OBJECTIVE: Standardized consensus criteria for remission in schizophrenia were recently proposed. The present study applied the symptom-severity component of these criteria to a sample of inpatients in order to determine the rates of remission during inpatient treatment and to explore predictors of remission. METHOD: A total of 288 inpatients from a multi-centre follow-up programme who fulfilled ICD-10 criteria for schizophrenia were included in the present analyses. PANSS ratings at admission and at discharge from hospitalization were used to examine remission status. Clinical and sociodemographic variables at admission were tested for their ability to predict remission at discharge. RESULTS: In total, 55% of the sample achieved symptom remission during inpatient treatment; 84% percent showed remission with respect to 'reality distortion', 85% with respect to 'disorganization' and only 65% with respect to 'negative symptoms'. Logistic regression analysis revealed that the global functioning (GAF) in the year before admission, the total score of the Strauss-Carpenter Prognostic Scale and the PANSS negative subscore at admission were predictive for symptom remission. The regression model showed a predictive value of about 70% and explained 36% of the observed variance. CONCLUSION: The results highlight the impact of negative symptoms for the course and treatment response of schizophrenic illness.

Functional serotonin 1A receptor variant influences treatment response to atypical antipsychotics in schizophrenia.

The serotonin (5-HT) 1A receptor has been found to be dysregulated in prefrontal cortex and other brain regions in schizophrenia, and 5-HT1A receptor levels in the amygdala have been related to negative schizophrenia symptoms. We have assessed the impact of the functional C-1019G variant of the 5-HT1A receptor on the response to risperidone or haloperidol in a prospective, randomized, double-blind study. Patients were treated for 4 weeks and negative symptoms assessed weekly. The variant influenced the response to risperidone: improvement of negative symptoms by 4.38 points for carriers of the C allele, compared with the GG genotype (1.22 points, P=0.046). In a second independent study of 130 schizophrenia patients treated with atypical antipsychotics, this effect was confirmed (P=0.003). The functional variant of the 5-HT1A receptor thus influences the response of schizophrenia patients to atypical antipsychotics and may be useful in the future to predict the pharmacogenetics of negative symptoms.

Further evidence for a functional role of the glutamate receptor gene GRM3 in schizophrenia.

In recent years, evidence has been accumulating indicating a major role of glutamate in the pathogenesis and pathophysiology of schizophrenia. Of particular importance in this regard are the metabotropic glutamate receptors (GRM). Thus, a recently published trial of the amino acid analogue LY2140023, which exerts its effects through the activation of the glutamate receptors GRM3/GRM2, showed an improvement of positive and negative symptoms comparable to treatment with olanzapine. A functional variant of GRM3 has been described which modulates synaptic glutamate levels. We assessed whether this functional variant rs6465084 is related to schizophrenia in a large sample of patients and controls. We found an increased frequency of the A allele (p=0.027) and the AA genotype (p=0.024) in schizophrenia patients. Moreover, in an assessment of schizophrenia endophenotypes, patients of the AA genotype performed poorly in the digit symbol test, a measure of attention (p=0.008). Our results provide further evidence for the potential importance of the glutamate receptor GRM3 in schizophrenia, and indicate that the novel antipsychotic LY2140023 may actually be targeting a pathogenic pathway of schizophrenia.

Impaired sensorimotor gating of the acoustic startle response in the prodrome of schizophrenia.

BACKGROUND: Schizophrenia patients exhibit impairment in prepulse inhibition (PPI) of the acoustic startle response (ASR), which is commonly interpreted as a sensorimotor gating deficit. To date, it is unclear when these gating deficits arise. Results of animal studies and some human data suggest that PPI deficits are in part genetically determined, such that gating deficits could be present before the onset of a full-blown psychosis. To test this assumption, we investigated PPI of ASR in individuals with prodromal symptoms of schizophrenia and patients with first-episode schizophrenia. METHODS: Startle reactivity, habituation, and PPI of ASR, as well as a neuropsychological test battery, were assessed in 54 subjects with prodromal symptoms of schizophrenia (35 early and 19 late prodromal subjects), 31 first-episode schizophrenia patients (14 unmedicated, 17 medicated), and 28 healthy control subjects. Patients were also examined with the Positive and Negative Syndrome Scale and the Global Assessment of Functioning Scale. RESULTS: Prodromal subjects and unmedicated patients with first-episode schizophrenia showed significant PPI deficits, whereas schizophrenia patients treated with risperidone had almost normal PPI. Startle reactivity decreased with greater severity of symptoms (control subjects, early prodromal group > late prodromal group > unmedicated first-episode patients) but was almost normal in the medicated patients. With respect to habituation, prodromal subjects and schizophrenia patients did not differ from healthy control subjects. CONCLUSIONS: PPI disruption is already present in a prodromal state of schizophrenia, but startle reactivity deficits seem to emerge with the onset of acute psychosis.

Prolactin, subjective well-being and sexual dysfunction: an open label observational study comparing quetiapine with risperidone.

INTRODUCTION: Sexual dysfunction is a frequent side effect of antipsychotic treatment. Increased prolactin levels are believed to be responsible for this sexual impairment despite contradictory results. AIM: The primary objective of the present study was to examine the relationship between sexual dysfunction, subjective well-being and prolactin levels in patients with schizophrenia treated either with risperidone or quetiapine. The secondary objective was to explore the relationship between testosterone and the severity of positive and negative symptoms of schizophrenia in male patients. METHODS: In a 4-week nonrandomized open label observational study, 102 inpatients with schizophrenia were recruited. Sexual functioning, subjective well-being and endocrinological parameters were assessed as well as psychopathological characteristics. MAIN OUTCOME MEASURES: Two self-rating questionnaires concerned with sexual functioning ("Essener Fragebogen zur Sexualität") and Subjective Well-Being Under Neuroleptic Treatment Scale (SWN) were completed by the patients. Plasma levels of prolactin in male and female patients were measured. Furthermore, in male patients testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were determined. Positive and Negative Symptom Scale (PANSS) was applied. RESULTS: After 4 weeks, patients treated with quetiapine reported less severe sexual impairment, as well as lower PANSS negative and general score compared with patients treated with risperidone. Additionally, emotional regulation as measured with the SWN was higher in patients treated with quetiapine. Risperidone was significantly associated with elevated prolactin levels. Prolactin levels were not correlated either with sexual dysfunction or PANSS. However, in the group of patients treated risperidone, sexual impairment was significantly associated with the SWN subscale emotional regulation. CONCLUSIONS: Increased prolactin levels do not seem to be decisive for antipsychotic induced sexual dysfunction. Improvement of severity of illness and regaining the ability to regulate one's own emotion have positive influence on sexual functioning.

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.