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DOI: 10.1055/s-2007-991786
5-HTTLPR polymorphism influences amygdala volume
Introduction: Structural abnormalities of amygdala have been documented in patients with schizophrenia (volume reduction) and bipolar disorder (volume enlargement). The aim of this study was to investigate the amygdala volume and the influence of the 5HTTLPR polymorphism on it in a sample of patients with schizophrenia or bipolar disorder compared to healthy individuals. Subjects: 56 individuals (17 healthy controls, 23 patients with schizophrenia, 27 patients with bipolar I disorder) participated in the study. MRI scanning was performed on a 1.5 Tesla Magnetom using a T1-weighted, MPRAGE sequence of 176 consecutive slices with a voxel size of 1 mm3. The amygdale volumes were estimated by manually tracing of the amygdale by an investigator blind to diagnosis. We computed the relative volumes of left and right amygdale by dividing absolute volumes through total gray matter volume. The 5HTTLPR polymorphism was genotyped in all individuals. Results: No differences of amygdale volumes were observed between patients with bipolar disorder or schizophrenia and control subjects. But short-allele carriers showed a significant larger relative volume of right amygdala. Conclusion: In contrast to previous findings we could not observe significant volumetric abnormalities of amygdale in patients with bipolar disorder. Alterations of amygdale volumes seems to be more influenced by 5HTTLPR genotype than diagnosis status.