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%.

Aripiprazole as an adjunct to clozapine therapy in adolescents with early-onset schizophrenia: a retrospective chart review.

INTRODUCTION: Combination of antipsychotic substances is a therapeutic option increasingly applied in patients with schizophrenia, who do not respond to antipsychotic monotherapy. Recently, various reports on combination of clozapine with aripiprazole in adults have been published. As there is not yet data on adolescent patients, we aimed to study the above-mentioned augmentation strategy in this population. METHODS: We included 15 patients with schizophrenia from a child and adolescent psychiatric department (8 male; mean age 19.3 [SD+/-1.2, range 17.2-21.2] years). Patients had been under clozapine treatment, followed by aripiprazole augmentation. Retrospectively, patients' medical records were reviewed, using a rating scale in analogy to the Clinical Global Impressions (CGI) scale. RESULTS: Mean observation time was 11.1 [SD+/-9.7] months. Mean CGI-Severity scores improved significantly (p=0.003, d=0.76) from 5.3 (baseline) to 4.5 (endpoint; last observation carried forward (LOCF)). CGI-Improvement scores decreased from 3.7 (after 1 month) to 3.3 (endpoint; LOCF) (p=0.212, d=0.45). CONCLUSIONS: In adolescents with schizophrenia, aripiprazole augmentation of clozapine treatment might be an effective therapeutic strategy. Prospective studies for this age group are required to obtain more specific clinical data on clinical effectiveness.

Schizophrenia and related disorders in children and adolescents.

This paper reviews the concept and recent studies on childhood and adolescent psychoses with special reference to schizophrenia. After a short historical introduction, the definition, classification, and epidemiology of child- and adolescent-onset psychoses are described, pointing out that some early-onset psychotic states seem to be related to schizophrenia (such as infantile catatonia) and others not (such as desintegrative disorder). The frequency of childhood schizophrenia is less than 1 in 10,000 children, but there is a remarkable increase in frequency between 13 and 18 years of age. Currently, schizophrenia is diagnosed according to ICD-10 and DSM-IV criteria. The differential diagnosis includes autism, desintegrative disorder, multiplex complex developmental disorder (MCDD) respectively multiple developmental impairment (MDI), affective psychoses, Asperger syndrome, drug-induced psychosis and psychotic states caused by organic disorders. With regard to etiology, there is strong evidence for the importance of genetic factors and for neurointegrative deficits preceding the onset of the disorder. Treatment is based upon a multimodal approach including antipsychotic medication (mainly by atypical neuroleptics), psychotherapeutic measures, family-oriented measures, and specific measures of rehabilitation applied in about 30% of the patients after completion of inpatient treatment. The long-term course of childhood- and adolescent-onset schizophrenia is worse than in adulthood schizophrenia, and the patients with manifestation of the disorder below the age of 14 have a very poor prognosis.

Prevalence of obesity in adolescent and young adult patients with and without schizophrenia and in relationship to antipsychotic medication.

The prevalence of obesity in inpatients of a German psychiatric rehabilitation center for adolescents and young adults (mean age 19.5 years) is assessed and set into relationship to diagnosis and medication regimen. In a cross-sectional naturalistic study body weights and heights of 151 inpatients, 109 of whom presented with ICD-10 schizophrenia spectrum disorders, were measured for the calculation of body mass indices (BMI, kg/m2); current medication regimen including the duration of treatment was assessed from medical records. BMIs were plotted into gender- and age-specific BMI-percentiles representative for the German population. Among the whole study population, obesity (BMI > or =90th percentile) was apparent in 44/98 (45%) of the male and in 31/53 (59%) of the female inpatients (overall: 50%). With respect to schizophrenia spectrum disorders, 36/70 (51%) males and 25/39 (64%) females (overall: 56%) were obese in contrast to 14/42 (33%) among the individuals without schizophrenia. Set into relationship to the treatment groups, the prevalence rates of obesity were 64% in patients treated with clozapine (n=69), 56% for other atypical antipsychotics (olanzapine, sulpiride, risperidone; n=27), 30% for classic antipsychotics (haloperidol, flupentixol, perazine; n=20) and 28% for the currently drug-free group (n=25). Together with other published findings in adults, these results suggest an increased prevalence of obesity among young patients with schizophrenia and especially among patients chronically treated with atypical antipsychotics.

Forty-two-years later: the outcome of childhood-onset schizophrenia.

This paper describes the long-term course of 76 patients who had been consecutively admitted to the Department of Child and Adolescent Psychiatry, Philipps University, between 1920 and 1961 with a suspected diagnosis of childhood-onset schizophrenia. By means of a consensus analysis of available data in accordance with ICD-10 criteria, the diagnosis of schizophrenia was confirmed in only 50% of the original sample (n = 38, childhood-onset schizophrenia group); whereas the rest of the sample were allotted other diagnoses (n = 38, non-schizophrenia group). A follow-up investigation was conducted, interviewing all available patients, if possible, or their first-degree relatives or doctors. In the childhood-onset schizophrenia group, age at onset (mean +/- S.D.) was 12.7 +/- 2.5 (range 5-14) years and age at follow-up was 55.0 +/- 4.8 (range 42-62) years. The outcome of this group was poor. According to the Global Assessment Scale (GAS), only 16% had a good (GAS score 71-100) and 24% had a moderate (GAS score 41-70) outcome. In the 16 childhood-onset schizophrenia patients who could be personally investigated at follow-up, 10 (62.5%) displayed severe or moderate depressive symptoms according to the BPRS depressive score. The death rate (including suicide) was significantly higher in the schizophrenia group (n = 15; 39.5%) than in the non-schizophrenia group (n = 7; 18.4%). A comparison of the life-time diagnoses of the total sample (n = 76) at follow-up with the ICD-10 diagnoses made retrospectively revealed a diagnostic stability in 69 (91%) and a change of diagnosis in 7 (9%) cases, among them 4 who were originally diagnosed as having childhood-onset schizophrenia.

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.

A prospective study of serum ghrelin levels in patients treated with clozapine.

We investigated serum ghrelin levels (SGL) in 12 patients with schizophrenia over a 10-week period after initiation of clozapine treatment. In contrast to increments of body mass indices (BMI, kg/m2) and serum leptin levels (SLL), no significant change in SGL was detected. Inverse correlations between delta SGL and delta SLL did not reach statistical significance. Linear mixed model analysis could not detect effects of age, sex, BMI, SLL and serum clozapine levels on SGL. Our results do not support a causal involvement of ghrelin in clozapine-related weight gain.

Spectrum of binge eating symptomatology in patients treated with clozapine and olanzapine.

The authors explored the binge eating symptomatology in 74 patients receiving clozapine (N = 57) or olanzapine (N = 17), and compared body mass index (BMI, kg/m(2)) and weight gain in patients with and without binge eating symptomatology. Subjects who screened positively for binge eating were interviewed using a modified version of the Questionnaire on Eating and Weight Patterns (QEWP). Current BMIs were assessed cross-sectionally, BMIs at initiation of clozapine/olanzapine treatment retrospectively. Thirty-seven subjects (50%) screened positively. Taking clozapine and olanzapine together, 6/27 (22.2%) females and 3/47 (6.4%) males fulfilled criteria for binge eating disorder, 3/27 (11.1%) females and 2/47 (4.3%) males for bulimia nervosa. Patients who screened positively showed higher current BMIs (26.8 +/- 3.9 vs. 24.7 +/- 3.7 kg/m(2)) and higher BMI increments during clozapine/olanzapine treatment (3.9 +/- 3.1 vs. 2.6 +/- 3.4 kg/m(2)) than patients who screened negatively. We conclude that clozapine/olanzapine may induce binge eating and full blown eating disorders which may have predictive value for weight gain. For future research in this field we suggest a novel DSM-IV research classification "Medication-induced eating disorders".