Is suicide risk correlated to thyroid weight?

Disturbances in some endocrine hormones have been implicated in the pathophysiology of depression and psychosis. We consider here further the hypothesis that there may be a correlation between suicide risk and the weight of the thyroid gland. The thyroid weight and other relevant information (sex, BMI) were collected retrospectively from 576 autopsies including 299 cases of completed suicide, analyzed in the west area of Paris between 1994 and 2010. Multiple regression model, adjusted on sex and BMI, confirmed that only for subjects more than 60 years of age, deceased by suicide, had a significant decrease in their weight of thyroid compared to those who deceased for another cause (decrease of around 3g, p=0.03, for age class 60 and over). Our hypothesis is that there could exist an anatomical correlate (thyroid weight) among people who have committed suicide, especially old individuals. Various hypotheses regarding the hypothalamus-pituitary-thyroid axis dysfunction and the physiopathology of major depression are proposed and discussed. Further studies will be necessary in order to confirm that such a tendency exists on other populations.