Correlations between mood disorders and a variety of structural abnormalities in the brain suggest that reduced volume in the ____ is related to depression.

A) amygdala
B) hypothalamus
C) hippocampus
D) thalamus

Studies have consistently found reduced volume in the hippocampus in individuals with depression. The hippocampus plays a role in regulating emotions and is also involved in learning and memory processes. Reduction in volume may lead to impaired regulation of emotions and cognitive functions, contributing to the development of depression. The other brain regions listed (amygdala, hypothalamus, and thalamus) have also been implicated in mood disorders, but there is stronger evidence for the role of the hippocampus in depression.