Faculty Bibliography

The relationship between orbitofrontal cortex (OFC) volumes and functional domains in treatment-resistant patients with schizophrenia or schizoaffective disorder is poorly understood. OFC dysfunction is implicated in several of the behaviors that are abnormal in schizophrenia. However, little is known about the relationship between these behaviors and OFC volumes. Forty-nine patients received magnetic resonance imaging scanning as part of a double-blind treatment study in which psychiatric symptomatology, neuropsychological function, and aggression were measured. OFC volumes were manually traced on anatomical images. Psychiatric symptomatology was measured with the Positive and Negative Syndrome Scale (PANSS). Aggression was measured with the Overt Aggression Scale (OAS) and with the PANSS. Neuropsychological function was assessed using a comprehensive test battery. Larger right OFC volumes were associated with poorer neuropsychological function. Larger left OFC gray matter volumes and larger OFC white matter volumes bilaterally were associated with greater levels of aggression. These findings are discussed in the context of potential iatrogenic effects

G-proteins are composed of alpha, beta and gamma subunits. Once activated, these subunits play a major role in the conversion of external receptor activation into intracellular signals. The functional C825T polymorphism of the beta3 subunit gene (GNB3) has recently been shown to modulate antidepressant response, with the T-allele conferring an increased signaling and being associated with favorable antidepressant response. We hypothesized that this polymorphism may be associated with response to antipsychotics in a population of 145 chronic schizophrenic patients deriving from two study-samples and being mainly treated with clozapine for up to 6 months. Overall, the C/C genotype was significantly associated with relative clinical improvement as measured by Brief Psychiatric Rating Scale (BPRS) change scores after 6 and 12 weeks (p<0.01 and p=0.03, respectively), with estimated effect sizes ranging from 4.8 to 7%. Our results further suggest that this effect is only attributable to Caucasians when compared to African-Americans. Moreover, our findings point to the role of intracellular mechanisms in antipsychotic response

Long-acting injectable antipsychotic formulations of conventional antipsychotics were developed to address the problem of partial adherence among patients with schizophrenia. Injection site pain, other skin reactions and patient satisfaction with treatment were assessed in two large, multicentre studies of long-acting injectable risperidone (Risperdal CONSTAtrade mark, Janssen Pharmaceutica Products, Titusville, New Jersey, USA), the first available long-acting atypical antipsychotic agent. Patients rated injection site pain using a 100-mm Visual Analogue Scale (VAS), and investigators rated injection site pain, redness, swelling and induration. Patient satisfaction with treatment was assessed with the Drug Attitude Inventory (DAI). VAS pain ratings were low at all visits across all doses in both studies, and decreased from first to final injection. In the 12-week, double-blind study, mean+/-SD VAS scores at the first and final injections were 15.6+/-20.7 and 12.5+/-18.3 for placebo-treated patients, and 11.8+/-14.4 (first) and 10.0+/-12.4 (final) for 25 mg; 16.3+/-21.9 (first) and 13.6+/-21.7 (final) for 50 mg; and 16.0+/-17.9 (first) and 9.6+/-16.0 (final, P<0.01) for 75 mg of long-acting risperidone. Mean VAS scores in the 50-week, open-label study at the first and final injection were: 17.9+/-22.2 (first) and 9.5+/-16.7 (final, P<0.0001) for 25 mg; 18.1+/-19.7 (first) and 10.4+/-14.8 (final, P<0.0001) for 50 mg; and 18.5+/-21.6 (first) and 13.6+/-19.9 (final, P=0.0001) for 75 mg of long-acting risperidone. Overall, there was no or minimal injection site pain and skin reactions were rare. Mean DAI ratings were available for the 50-week study and indicated high patient satisfaction throughout the trial (baseline=7.30; endpoint=7.70; P<0.0001 versus baseline). These findings may positively affect patient and clinician attitudes towards long-term therapy with long-acting injectable risperidone

Some reports have indicated increased rates of diabetes and increased prevalence of glucose and lipid abnormalities during treatment with second-generation antipsychotics, with most concern raised about clozapine and olanzapine. Most of the findings have come from case reports, retrospective examination of laboratory values, and analysis of health-care claims databases. This study investigated fasting levels of glucose, lipids, and leptin in a non-randomized, cross- sectional study of 210 patients, with schizophrenic or schizoaffective disorder, treated with a single antipsychotic medication - clozapine, risperidone, olanzapine, or a conventional antipsychotic. Glucose tolerance tests (GTT), with a 75-g glucose load, were preformed in a subset of patients. In this sample most mean fasting glucose and lipid levels were within the normal range and were not significantly different across the four drug treatment groups. Patients treated with clozapine and olanzapine had higher triglyceride levels than risperidone patients. In patients receiving a GTT, risperidone-treated patients had higher glucose levels at 1 h than patients treated with olanzapine, and there were more patients on risperidone who met American Diabetes Association glucose metabolic criteria for diagnosis of diabetes. Although there were no significant differences in age or body mass index among the four drug groups, we cannot rule out some potential biasing factors we did not assess which could potentially influence our results. These include unknown physician preference in drug selection based on their beliefs about the weight-inducing or diabetes potential of different antipsychotics, differences in visceral fat, and differences in patients' antipsychotic drug history

The synaptosomal-associated protein of 25 kDa (SNAP-25) is an essential component of the core complex that mediates presynaptic vesicle trafficking. Thus, SNAP-25 is directly involved in the release of neurotransmitters. Quantitative alterations of SNAP-25 expression have been reported in brain regions and cerebrospinal fluid (CSF) of schizophrenics and in haloperidol treated rats. This observed altered expression may be influenced by genetic variants of SNAP-25. We hypothesized that polymorphisms of the SNAP-25 gene (sites DdeI, MnlI and TaiI in the 3'UTR) are associated with antipsychotic drug response and induced weight gain. A sample of 59 patients with prior suboptimal response to antipsychotic treatment and diagnosed with DSM-IV schizophrenia or schizoaffective disorder was examined. Patients were administered clozapine, haloperidol, olanzapine or risperidone for up to 14 weeks. Clinical response was defined as the difference between the baseline and the endpoint total scores on the Positive and Negative Syndrome Scale (PANSS). Weight was assessed at baseline and at study endpoint. ANOVA revealed that the MnlI and TaiI polymorphisms were associated with response (F[2,53] = 4.57, p = 0.01 and F[2,52] = 3.53, p = 0.03) and with weight gain (F[2,52] = 4.28, p = 0.01 and F[2,51] = 3.38, p = 0.04). When covariates were included, the MnlI polymorphism remained significantly associated with changes of PANSS scores, but not with weight gain. The DdeI polymorphism was not associated with response or weight gain. These findings suggest that SNAP-25 gene variants affect clinical response in patients with prior poor response to antipsychotics. Weight changes do not seem to be associated with polymorphism of the SNAP-25 gene, however, replication in independent samples is warranted

Neurocognitive deficits are recognized as a cardinal feature of schizophrenia. Atypical antipsychotics have high affinity for many neurotransmitter receptors. Among these receptors, antipsychotics are antagonists of adrenoceptors, and this pharmacological property has been postulated to be involved in the mechanism of action of antipsychotics. We tested the hypotheses that clinical response and cognitive improvement to antipsychotic treatment are associated with genetic variation in adrenergic alpha2C receptor (ADRA2C). Fifty-seven patients with chronic schizophrenia were prospectively assessed for clinical response to antipsychotic treatment. They were subsequently genotyped for a 21 bp insertion/deletion that we identified in the 3' untranslated region (3'UTR) of ADRA2C. With regard to clinical response and cognitive improvement to antipsychotics, there was no significant association observed for this polymorphism. Our results suggest that the novel polymorphism may not play a major role in antipsychotic response