Possible association between haplotypes of the FKBP5 gene and suicidal bipolar disorder, but not with melancholic depression and psychotic features, in the course of bipolar disorder

We aimed to analyzed the association between polymorphisms of the FKBP5 (FK506 binding protein 5) gene and subtypes of bipolar disorder. In the study, we included 195 bipolar disorder patients with psychotic features, 129 bipolar patients with melancholic depression, and 156 bipolar patients with a history of suicidal attempts. We found weak association between the haplotypes of the FKBP5 gene and bipolar patients with suicidal attempts. We did not find an association between polymorphisms of the FKBP5 gene and bipolar disorder with psychotic features, nor with bipolar disorder with melancholic depression. Limitations of our study are the absence of data about previous trauma exposure and the small sample size of patients, which of course can lead to false-positive results, so further validation and replication of the present findings are still needed.