Hippocampal volume reduction and HPA-system activity in major depression

There is ample evidence suggesting that elevated levels of glucocorticoids may render hippocampal cells more vulnerable. Major depression is frequently accompanied by hypercortisolemia. Therefore, it is hypothesized that lifetime duration of depression is inversely correlated with hippocampal volume. To test this hypothesis hippocampal volume (3D-MRI) and saliva cortisol was measured in 24 in-patients. Fourteen healthy elderly controls were matched for age and educational state. Patients with longer lifetime histories depression (>6 months) had significantly higher saliva cortisol levels (cortisol±S.D.=26.3±10.4 nmol/L) than patients with a shorter history of the affective disorder (<6 months) (cortisol±S.D.=17.8±2.3 nmol/L). Both patients groups were similar in age (mean age 57.6±12.1 resp. 51.4±11.2 years). In addition, patients with a longer history of depression tended to have smaller hippocampal volumes (3.11±0.39 vs. 3.44±0.41 mL; p<0.054) in comparison to their counterparts. These results strenghten the notion that repeated hypercortisolemic episodes during recurrent depression may lead to hippocampal volume loss.