Hippocampal volume in first episode and recurrent depression.

Abnormalities in limbic-thalamic-cortical networks are hypothesized to modulate human mood states. In the present study differences in hippocampal volumes of patients with a first episode of depression, recurrent major depression and healthy control subjects were examined with high-resolution magnetic resonance imaging (MRI). Male patients with a first episode of major depression had a significantly smaller left hippocampal volume than male control subjects. Also, these patients had a significant left-right asymmetry in hippocampal volume. Female patients showed no significant alterations in hippocampal volumes. The results support the hypothesis that the hippocampus plays an important role in the pathophysiology of the early phase of major depression, especially for male patients. Implications for the neurodevelopmental and the neurodegenerative model of hippocampal change are discussed.

Life events and hippocampal volume in first-episode major depression.

BACKGROUND: There are many studies on life events in depression and also several studies examining brain structural changes in the hippocampus of depressed patients. However, only few studies have focused on the association of life events and hippocampal volume in depression. The hypothesis of a significant negative association between life events and hippocampal volumes in first episode depression was examined. METHODS: 28 in-patients with a first episode of major depression were examined with high-resolution magnetic resonance imaging measuring hippocampal volumes. The precourse of depression was assessed with the Interview for the Retrospective Assessment of the Onset and Course of Schizophrenia and Other Psychoses (IRAOS) and life events by using the Munich Interview for the Assessment of Life Events and Conditions (MEL). RESULTS: A significant negative correlation between major life events three month before the onset of depression and the left hippocampal volume was found for male patients. In female patients no significant association between major life events and hippocampal volumes could be found. CONCLUSIONS: The results support the hypothesis that the hippocampus plays a crucial role in the pathogenesis of major depression in the early phase of the disorder particularly for male patients.