Time to Initiation of Clozapine Treatment in Children and Adolescents with Early-Onset Schizophrenia.

Introduction: Early-onset schizophrenia (EOS) has a poor prognosis and is difficult to treat, which often leads to the initiation of clozapine treatment. Studies in adults have shown that the initiation of clozapine treatment is often delayed. There is a lack of studies concerning the initiation of clozapine in children and adolescents with EOS. The aim of this study was to investigate the time span from first EOS-related psychiatric hospitalization to clozapine initiation. Methods: We retrospectively studied a consecutive cohort of children and adolescents with EOS and first-time clozapine prescriptions from a tertiary care child and adolescent psychiatric center in Germany. Results: Clinical records with data on clozapine initiation were available for 112 patients (35.7% females, mean age: 15.2±1.6 years). The mean time from first EOS-related hospitalization to clozapine initiation was 1.1 (±1.0) years, with an average of 2.3 (±1.1) prior antipsychotic treatment episodes. Higher age and higher IQ predicted earlier clozapine initiation. At the time of clozapine initiation, 40.2% of patients received antipsychotic polypharmacy. Prior to clozapine, 33.9% of patients had received 3 or more antipsychotic treatment episodes. Discussion: In our study, clozapine treatment was initiated markedly earlier than in the few existing studies, which may partly be due to the expected poor prognosis of EOS. The significant portion of patients undergoing 3 or more antipsychotic trials or antipsychotic polypharmacy prior to clozapine may indicate a need for improved dissemination of knowledge on the effectiveness of clozapine in treatment-resistant schizophrenia in order to promote timely clozapine prescriptions in these cases.

Association study of energy homeostasis genes and antipsychotic-induced weight gain in patients with schizophrenia.

INTRODUCTION: Marked inter-individual variation has been observed with respect to the risk of weight gain and related metabolic disturbances during antipsychotic treatment, which in part could be explained by heritability. Such adverse effects have been proposed to occur through drug-induced mechanisms involving both the central nervous system and different peripheral tissues. METHODS: We genotyped tagSNPs in several genes ( ADIPOQ, PRKAA1, PRKAA2, PRKAB1, PRKAG1, PRKAG2, PRKAG3, FTO and FABP3) that regulate lipid and energy homeostasis for their possible association to antipsychotic-induced weight gain. RESULTS: In a sample of 160 patients of German origin with schizophrenia who had been monitored with respect to body weight, we found marked association between antipsychotic-related changes in BMI and 6 markers in the adiponectin gene ( ADIPOQ). DISCUSSION: These findings support previous observations (in patients' serum) that adiponectin is involved in antipsychotic-mediated metabolic adverse effects.

Association between the insulin-induced gene 2 (INSIG2) and weight gain in a German sample of antipsychotic-treated schizophrenic patients: perturbation of SREBP-controlled lipogenesis in drug-related metabolic adverse effects?

Atypical antipsychotics are nowadays the most widely used drugs to treat schizophrenia and other psychosis. Unfortunately, some of them can cause major metabolic adverse effects, such as weight gain, dyslipidemia and type 2 diabetes. The underlying lipogenic mechanisms of the antipsychotic drugs are not known, but several studies have focused on a central effect in the hypothalamic control of appetite regulation and energy expenditure. In a functional convergent genomic approach we recently used a cellular model and demonstrated that orexigenic antipsychotics that induce weight gain activate the expression of lipid biosynthesis genes controlled by the sterol regulatory element-binding protein (SREBP) transcription factors. We therefore hypothesized that the major genes involved in the SREBP activation of fatty acids and cholesterol production (SREBF1, SREBF2, SCAP, INSIG1 and INSIG2) would be strong candidate genes for interindividual variation in drug-induced weight gain. We genotyped a total of 44 HapMap-selected tagging single nucleotide polymorphisms in a sample of 160 German patients with schizophrenia that had been monitored with respect to changes in body mass index during antipsychotic drug treatment. We found a strong association (P=0.0003-0.00007) between three markers localized within or near the INSIG2 gene (rs17587100, rs10490624 and rs17047764) and antipsychotic-related weight gain. Our finding is supported by the recent involvement of the INSIG2 gene in obesity in the general population and implicates SREBP-controlled lipogenesis in drug-induced metabolic adverse effects.

Body weight gain induced by atypical antipsychotics: an extension of the monozygotic twin and sib pair study.

BACKGROUND AND OBJECTIVE: In our original study based on five monozygotic twin pairs and seven same-sex sib pairs, we previously showed that genetic factors contribute to body weight gain induced by the atypical antipsychotic clozapine. We aim to study this further by including patients treated with the atypical antipsychotics olanzapine or risperidone as well as opposite-sex sib pairs. METHODS: Twin and sib pairs were identified by a telephone screening. Measured data on weight and other clinical variables were obtained cross-sectionally and retrospectively from medical records. In seven monozygotic twin pairs and 12 sib pairs (total number of patients treated: n = 38, mean age 29.5 +/- 9.5, range 13.7-54.3 years), the similarity in BMI (kg/m(2)) change under these atypical antipsychotics (atypical Delta BMI) and upon additional inclusion of BMI change under prior antipsychotic medication (total Delta BMI) was explored. RESULTS: For total Delta BMI we found greater similarity in antipsychotic-induced BMI change in MZ twin pairs than in sib pairs (intrapair difference) with a heritability of h(2) = 0.6, but not for atypical Delta BMI, possibly because of a genetically influenced weight plateau achieved under antipsychotic medication. CONCLUSION: The results of the present and our previous report suggest a contribution of genetic factors in antipsychotic-induced weight gain of 60-80%.

Clozapine/olanzapine-induced recurrence or deterioration of binge eating-related eating disorders.

OBJECTIVE: To explore the association between eating disorders (EDs) prior to the use of clozapine/olanzapine (pre-clozapine/olanzapine EDs) and after initiation of these antipsychotics (post-clozapine/olanzapine EDs). METHOD: Sixty-four consecutively admitted patients receiving clozapine/olanzapine were screened using the M-Composite International Diagnostic Interview (M-CIDI) to identify subjects with pre-clozapine/olanzapine EDs (DSM-IV criteria). We investigated post-clozapine/olanzapine EDs and binge eating behavior using the Questionnaire on Eating and Weight Patterns (QEWP) and used the Naranjo probability scale as objective causality assessment. RESULTS: Post-clozapine/olanzapine EDs were significantly more frequent in patients with pre-clozapine/olanzapine EDs (5 of 6) when compared to patients without pre-clozapine/olanzapine EDs (4 of 58) [chi(2) = 26.29; df = 1; p < 0.001] [odds ratio (OR) 67.5; 95% CI: 6.3-725.8]. According to the Naranjo probability scale, recurrence or deterioration of EDs in patients with prior EDs was definitely (n = 1) or probably (n = 4) related to the intake of clozapine/olanzapine. CONCLUSION: Clozapine/olanzapine may induce recurrence or deterioration of binge eating symptomatology or full-blown EDs in patients with prior EDs.

No evidence for binding of clozapine, olanzapine and/or haloperidol to selected receptors involved in body weight regulation.

The underlying mechanisms of antipsychotic (AP)-induced weight gain are unknown, but both central and peripheral AP target receptors could potentially be involved. This study used radioligand binding assays to compare the binding affinities of clozapine, olanzapine and haloperidol for candidate receptors potentially involved in AP-induced weight gain. Selected candidates derived from known pathways involved in body weight regulation included receptors classified as anorexigenic (bombesin receptor subtype 3, calcitonin gene-related peptide receptor, cholecystokinin receptor, melanocortin-4 receptor, neurotensin receptor 1) or orexigenic (cannabinoid receptor 1, galanin 1 receptor, melanin-concentrating hormone receptor (MCHR), neuropeptide Y1 receptor) as well as receptors involved in physiological actions related to digestion and fluid homeostasis (angiotensin II type 1 receptor, bradykinin B2 receptor, endothelin receptor, neurokinin 1 receptor, vasoactive intestinal polypeptide receptor 1). Clozapine, olanzapine and haloperidol exhibited negligible affinities to all of these receptors except for the MCHR (Ki=501 nM; haloperidol). With respect to other candidates from (neuro)transmitter systems already suggested to be involved in AP-induced weight gain, the binding profile of olanzapine resembled that of clozapine, with high affinity (Ki<10 nM) for serotonin (5-HT) 5-HT2A, 5-HT2C and 5-HT6, muscarinic M1 and histamine H1 receptors. In contrast, the binding profile of haloperidol was substantially different (high affinity only for the dopamine D1 receptor). In conclusion, we have not identified a novel binding site of the two investigated atypical AP that could contribute to the induced weight gain.