ABSTRACT
BACKGROUND: Recent data suggest that brain-derived neurotrophic factor (BDNF) and the serotonergic system are involved and interact in major depressive disorder and suicidal behavior (SB). Several family and population-based studies have reported associations between the BDNF gene and serotonin-related genes, specifically the serotonin transporter (5HTT) gene, with bipolar disorder (BD) and SB. However, despite the fact that gene-by-gene interaction between BDNF and 5HTT has been demonstrated in monoamine deficiencies in animals, this kind of interaction has never been tested in humans. Our hypothesis is that some BDNF and 5HTT polymorphisms might confer increased risk for BD and SB and that both genes may interact with each other. METHODS: To test this hypothesis, we genotyped the most common BDNF polymorphisms, G196A (Val66Met), A-633T and BDNF-LCPR, as well as 5HTT (5HTT-LPR), in 447 BD patients and 370 controls. RESULTS: We replicated the association previously reported between BDNF G196A (Val66Met) polymorphism and BD. We also observed a correlation between the number of G196 alleles and short alleles of 5HTT-LPR and the severity of SB in BD. However, we found no significant interaction between these two markers. CONCLUSIONS: These results suggest that BDNF G196A as well as 5HTT-LPR polymorphisms confer risk for SB in BD, but we did not observe any evidence for an interaction between them.
Subject(s)
Bipolar Disorder/genetics , Brain-Derived Neurotrophic Factor/genetics , Polymorphism, Genetic/genetics , Serotonin Plasma Membrane Transport Proteins/genetics , Suicide, Attempted/psychology , Adult , Alleles , Bipolar Disorder/diagnosis , Bipolar Disorder/psychology , Disease Susceptibility , Epistasis, Genetic , Female , Gene Frequency/genetics , Genotype , Humans , Male , Middle AgedABSTRACT
Oxidative stress could be involved in the pathophysiology of schizophrenia, a major psychiatric disorder. Glutathione (GSH), a redox regulator, is decreased in patients' cerebrospinal fluid and prefrontal cortex. The gene of the key GSH-synthesizing enzyme, glutamate cysteine ligase modifier (GCLM) subunit, is strongly associated with schizophrenia in two case-control studies and in one family study. GCLM gene expression is decreased in patients' fibroblasts. Thus, GSH metabolism dysfunction is proposed as one of the vulnerability factors for schizophrenia.
Subject(s)
Genetic Predisposition to Disease/genetics , Glutamate-Cysteine Ligase/genetics , Oxidative Stress/genetics , Schizophrenia/genetics , Case-Control Studies , Down-Regulation , Fibroblasts/enzymology , Fibroblasts/metabolism , Gene Frequency , Glutathione/metabolism , Humans , Polymorphism, Single Nucleotide , RNA, Messenger/analysis , Schizophrenia/enzymologyABSTRACT
The semi-structured diagnostic interview for genetic studies (DIGS) was developed to assess major mood and psychotic disorders and their spectrum manifestations in genetic studies. Our research group developed a French version of the DIGS and tested its inter-rater and test-retest reliability in psychiatric patients. In this article, we present estimates of the reliability of substance use and antisocial personality disorders. High kappa coefficients for inter-rater reliability were found for drug and alcohol as well as antisocial personality diagnoses and slightly lower kappas for test-retest reliability. Combined with evidence of the reliability of major mood and psychotic disorders, these findings support the suitability of the DIGS for studies of familial aggregation and comorbidity of psychiatric disorders including substance use and antisocial personality disorders.
