Enlarged hypothalamic volumes in schizophrenia

Hypothalamic abnormalities in schizophrenia have been associated with endocrine dysfunctions and stress response. The hypothalamus is involved in several pathways found disrupted in schizophrenia (e.g. hypothalamic-pituitary-adrenal axis, HPA axis); however the available results on potential structural hypothalamic alterations are still controversial. The aim of the study was to investigate the volumes of the hypothalamus and the mammillary bodies in patients with schizophrenia and healthy controls. Twenty-six patients with schizophrenia and 26 healthy controls underwent a 3 Tesla magnetic resonance imaging (MRI) scan. Hypothalamus and mammillary bodies were manually traced by a rater who was blind to subjects' identity. The General Linear Model was used in group comparisons of the volumes of the hypothalamus and the mammillary bodies. The hypothalamus and mammillary body volumes were significantly larger in patients with schizophrenia than controls, with significant enlargement of the left hypothalamus and trends for significantly increased right hypothalamus and right mammillary body. The size of the mammillary bodies was inversely correlated with negative symptoms and directly correlated with anxiety. This study showed abnormally increased sizes of the hypothalamus and the mammillary bodies in schizophrenia. Mammillary bodies volumes were associated to negative symptoms and anxiety. Future longitudinal studies on the volumes of the hypothalamus and the mammillary bodies with respect to the levels of related hormones will clarify their role in modulating HPA axis in schizophrenia.