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.