Increased Incidence of Pituitary Microadenomas in Suicide Victims

Abstract

Background: Current data suggest an influence of the hypothalamic-pituitary-adrenal axis on suicidal behavior. The frequency of pituitary adenomas in suicide victims has not yet been investigated. Objectives: The aim of this study was to assess whether the incidence of pituitary adenomas is correlated with suicide. Methods: Serial sections of 151 human pituitary glands obtained upon autopsy were examined microscopically. The glands were collected from 70 suicide victims and 81 subjects whose deaths were classified as unexpected or accidental (nonsuicidal group). The sections were stained with hematoxylin-eosin and the presence of adenoma was confirmed by immunostaining for collagen III. Results: In the suicidal group, pituitary microadenomas were found in 32 cases (47.7%), while in the nonsuicidal group microadenomas were detected in 15 cases (18.3%). The observed difference was statistically significant (p = 0.0003). The relative risk ratio of suicide in persons with pituitary adenomas was estimated at 1.9. Logistic regression analysis in a model controlled for age and sex showed that microadenomas constituted a unique risk factor in this model. The immunohistochemical phenotyping revealed a higher percentage of immunopositive (secreting) microadenomas in the nonsuicidal group as compared to the suicidal group (80.0 vs. 59.38%) and a predominance of growth hormone-secreting microadenomas in both groups. However, these differences as well as differences in the hormonal profiles of microadenomas between the groups were not significant. Conclusions: These results suggest that pituitary adenomas belong to suicide risk factors.