Background: Evidence for structural hippocampal change in depression is limited despite reports of neuronal damage due to hypercortisolaemia and vascular pathology.
Aims: To compare hippocampal and white matter structural change in demographically matched controls and participants with early-onset and late-onset depression.
Method: High-resolution volumetric magnetic resonance imaging (MRI) and rating of MRI hyperintensities.
Results: A total of 51 people with depression and 39 control participants were included. Participants with late-onset depression had bilateral hippocampal atrophy compared with those with early-onset depression and controls. Hippocampal volumes did not differ between control participants and those with early-onset depression. Age of depression onset correlated (negatively) with hippocampal volume but lifetime duration of depression did not. Hyperintensity ratings did not differ between groups.
Conclusions: Results suggest that acquired biological factors are of greater importance in late-than in early-onset illness and that pathological processes other than exposure to hypercortisolaemia of depression underlie hippocampal atrophy in depression of late life.