Enlarged amygdala volume and reduced hippocampal volume in young women with major depression

Background. Evidence is increasing that amygdala and hippocampus show significant structural abnormalities in affective disorders. Two previous studies found enlarged amygdala size in subjects with recent-onset major depression. Method. Amygdala and hippocampal volumes were assessed in 17 young women with major depressive disorder and 17 healthy matched control subjects by use of three-dimensional structural magnetic resonance imaging. The severity of depressive symptoms was assessed using the Hamilton Depression Scale and the Beck Depression Inventory. Results. Compared with control subjects, depressive subjects had significantly larger (+13%) amygdala volumes and significantly smaller (-12%) hippocampal volumes. Amygdala and hippocampal volumes were not significantly correlated with disorder-related variables. Conclusions. Our results are consistent with previous findings of structural abnormalities of amygdala and hippocampus in subjects with recent-onset major depression. It may be suggested that the size of the amygdala is enlarged in the first years of the disorder, and may decrease with prolonged disorder duration.