The role of genetic variation of BDNF gene in antidepressant-induced mania in bipolar disorder.

The occurrence of mania during antidepressant treatment is a key issue in the clinical management of bipolar disorder (BD). Brain-derived neurotrophic factor (BDNF) has been implicated in the pathogenesis of mood disorders. Moreover, antidepressants increase the expression of BDNF and its overactivity may be involved in the mechanism of development of the manic state. The aim of the present study was to test the influence of BDNF gene alterations in antidepressant-induced mania in bipolar patients. A case-control study was performed to analyse genotype and allele frequencies for the BDNF polymorphisms between two groups [37 patients with antidepressant-induced mania (AIM+) and 55 patients without antidepressant-induced mania (AIM-)]. No significant differences were found between AIM+ and AIM- groups. Our results did not support the BDNF gene link to antidepressant-induced mania, like a previous study with a smaller sample has already suggested.