Stephan Claes

Second generation antipsychotics in the treatment of bipolar depression: a systematic review and meta-analysis

Depressive symptoms and episodes dominate the course of bipolar disorder. However, the therapeutic armamentarium for bipolar depression is limited. Recent evidence points to the efficacy of second generation antipsychotics (SGAs) for the treatment of bipolar depression. We conducted a systematic review and meta-analysis of the efficacy and safety of SGAs (randomized, double-blind, placebo-controlled trials; used in monotherapy) in the treatment of adult patients with bipolar depression. Publication bias was corrected for by performing similar searches using the clinical trials register of the respective pharmaceutical companies, the Cochrane Database and ClinicalTrials.gov. Seven published papers were identified on the use of aripiprazole, olanzapine and quetiapine. Internal validity of the trials was fairly good, external validity only moderate. Different outcome measures of efficacy and safety were assessed. When the individual trials were looked at, quetiapine and to a lesser extent olanzapine demonstrated significant improvement in MADRS (Montgomery–Åsberg Depression Rating Scale) total scores. This was not demonstrated for aripiprazole. Efficacy was hampered by adverse events, such as weight gain, akathisia and somnolence/sedation. Both clinical heterogeneity of the included trials and statistical heterogeneity of the meta-analytic data were considerable. The number of quetiapine trials was disproportionate to the number of trials of aripiprazole and olanzapine. Further research is needed to assess differential efficacy of the different SGAs and their use in clinical practice.

Glucocorticoid receptor polymorphisms in major depression

Major depressive disorder (MDD) often appears after exposure to acute or chronic stress, and dysfunction of stress response systems, such as the hypothalamic‐pituitary‐adrenal (HPA) axis, is thought to be a key element of MDD neurobiology. The glucocorticoid receptor (GR) is the most important regulator of the HPA axis negative feedback system, and GR sensitivity has been shown to be reduced in MDD in both in vitro and in vivo studies. Transgenic animals with partial impairment of GR function show behavioral changes consistent with MDD. This makes the GR gene a prime candidate for research into the genetic background of MDD. Several single nucleotide polymorphisms (SNPs) have been detected that have specific effects on GR function, metabolic parameters, and HPA axis function in response to stress. Genetic association studies have yielded preliminary evidence for a role of these genetic variations in the genetic vulnerability for MDD. Taken together, the evidence for a role of GR and the GR gene in the neurobiology of MDD is building rapidly.

Clock genes and body composition in patients with schizophrenia under treatment with antipsychotic drugs

CONTEXTnIn the healthy population, several pathways are known to exert an effect on basal metabolic factors. Previous studies have found associations between single nucleotide polymorphisms in clock genes or downstream hormone receptors such as the leptin receptor (LEPR) or glucocorticoid receptor (NR3C1) and obesity in the healthy population, but this association remains to be examined in patients with schizophrenia treated with antipsychotics.nnnOBJECTIVEnTo assess anthropomorphic parameters in patients taking second-generation antipsychotics (SGA) as a function of nine polymorphisms in three core genes of the clock pathway, and two genes of downstream hormone receptors.nnnMETHODSnClinical parameters were evaluated in 261 patients with schizophrenia spectrum disorder. Polymorphisms in LEPR, MC3R, NR3C1, PER2 and SDC3 were genotyped. In order to control for multiple testing, permutation tests were used to generate corrected empirical p-values using the Max(T) procedure in PLINK.nnnRESULTSnA significant effect of the rs6196 polymorphism in the NR3C1 on weight (β=-4.18; SE=2.02; p=0.018), BMI (β=-1.88; SE=0.64; p=0.004), waist (β=-5.77; SE=1.75; p=0.001) and waist/hip ratio (β=-0.03; SE=0.012; p=0.009) was found. Permutation tests confirmed the findings for BMI (p=0.037) and waist (p=0.024). Carriers of the G allele consistently displayed better parameters than patients with the wild type allele. A weak effect of rs4949184 in SDC3 on BMI was found, but this did not sustain permutation testing (β=-1.27; SE=0.58; p=0.030, p=0.270 after permutations).nnnCONCLUSIONnVariations in genes implicated in circadian regulation or its related downstream pathways may be important in the regulation of antropomorphic parameters in patients with schizophrenia during long-term treatment with SGA.