Factors associated with subjective side-effects during clozapine treatment.

OBJECTIVE: Clozapine is associated with subjectively unpleasant or clinically serious side-effects, which may affect treatment adherence. The aims of the study were to explore the association of clozapine+ norclozapine serum concentration and other factors with subjective side-effects in schizophrenia patients. METHODS: In this cross-sectional study, 237 patients with a diagnosis of schizophrenia, schizo-affective or other non-organic psychoses completed the Liverpool University Neuroleptic Side Effect Rating Scale (LUNSERS), a self-report scale measuring side-effects of antipsychotics and a clinical questionnaire. Clozapine+ norclozapine serum concentration of 190 patients was measured. Of the patients 80 (33.7%) were on antipsychotic combination therapy. RESULTS: Higher clozapine+ norclozapine concentrations were associated with the depression-anxiety factor of LUNSERS and antipsychotic combination treatments were associated with sympatichotonia-tension factor. Younger patients reported sedation more often than older patients. CONCLUSION: According to the present results, high clozapine concentrations were associated with depression-anxiety symptoms, but the causality remains unknown.

No support for a role for BDNF gene polymorphisms rs11030101 and rs61888800 in major depressive disorder or antidepressant response in patients of Finnish origin.

Brain-derived neurotrophic factor (BDNF) is suggested to play a role in the aetiology of major depression and in the antidepressant response in patients with major depression. Several BDNF gene polymorphisms have been investigated in the above-mentioned context. The aim of the present study was to examine the role of two BDNF gene polymorphisms (rs11030101 and rs61888800) in relation to the response to selective serotonin reuptake inhibitor medication in 106 patients of Finnish origin suffering from major depression. The secondary objective was to evaluate the association of these two BDNF polymorphisms in major depression, as we also had a control population of 386 healthy individuals. We did not find any significant differences in the distribution of these two BDNF gene polymorphisms in our patient population in relation to remission or response to treatment with selective serotonin reuptake inhibitor. Also, there were no significant differences between the patients and the controls.

Temperament profiles, 5-HT2A genotype, and response to treatment with SSRIs in major depression.

Variation in antidepressive medication response according to 5-HT2A genotype has been reported in several studies. Temperament has been proposed to be one of the vulnerability factors in mood and anxiety disorders. We studied temperament profiles of 98 patients with major depression and explored the interaction between Temperament and Character Inventory (TCI) temperament dimensions, 5-HT2A genotype (SNPs rs6311, rs6313 and rs7997012) and treatment response. No interactive effects for TCI temperament dimensions and 5-HT2A genotypes on antidepressive treatment response were found.

Catechol-O-methyltransferase val108/158met genotype, major depressive disorder and response to selective serotonin reuptake inhibitors in major depressive disorder.

The functional val108/158met polymorphism of the COMT gene (rs4680) was evaluated in major depressive disorder (MDD), and in the treatment response to antidepressants in MDD. We could not demonstrate any significant difference in the distribution of this COMT single-nucleotide polymorphism (SNP) in the treatment response to selective serotonin reuptake inhibitors or between patients with MDD and control subjects.

TPH1 218A/C polymorphism is associated with major depressive disorder and its treatment response.

The association between the tryptophan hydroxylase 1 (TPH1) 218A/C polymorphism and (1) severity of major depressive disorder (MDD) and (2) response to treatment was studied. There were three study populations, the first consisting of 119 treatment-resistant MDD inpatients treated with electro-convulsive therapy (ECT), and the second of 98 MDD open care patients treated with selective serotonin reuptake inhibitors (SSRI). In addition, there was a control population of 395 healthy blood donors. The first aim of the study was to compare the genotypes of the patient with those of the healthy controls and between patient populations. The second aim was to compare the genotypes of MDD patients achieving remission with basic SSRI treatment (MADRS<8) with the genotypes of non-responders to ECT (defined as MADRS>15). TPH1 218A/C polymorphism was associated with the risk of MDD. CC genotype was significantly more common in patients (including both ECT and SSRI treated patients) than in controls (38.2% and 26.8% respectively; p=0.008), and its frequency was significantly higher in more severe forms of depression, i.e. in ECT treated patients compared with SSRI treated patients (42.0% and 33.7%, p=0.026). CC genotype was also associated with lower probability of achieving remission. It was significantly more frequent among ECT non-responders than among SSRI remitters (53.1% and 23.3%, p=0.049). In this Finnish population TPH1 218A/C polymorphism was associated with the risk of MDD and treatment response; CC genotype was associated with the increased risk of MDD and lower probability of responding treatment. Further studies with larger samples will be required to confirm the results.