Somatotype in Bipolar Disorder Revisited: Gender Differences, Neurodevelopment and Clinical Implications

Ninety-five years after Kretschmer’s original publication the concept of somatotype in psychiatry remains controversial. The aim of the current study was to compare the somatotype of patients with bipolar I disorder and sex-matched mentally healthy controls using an objective method of somatotyping and predefined inclusion and exclusion criteria. 67 bipolar I patients (26 males, 41 females) and 119 mentally healthy controls (54 males, 65 females) were assessed using the Heath-Carter Anthropometric Method. Bipolar I males were significantly less endomorphic and more ectomorphic than sexmatched controls. Bipolar I females were significantly less ectomorphic than sex-matched controls. We found significant interaction effects between gender and group membership on all somatotype components. Bipolar I males had significantly lower, while bipolar I females had significantly higher BMIs than controls. Kretschmer’s hypothesis may only apply to females. In an age of orexigenic mood stabilizers bipolar I females may be a particularly vulnerable treatment population. Our data suggest bipolar I disorder has neurodevelopmental underpinnings.