Neuroanatomical substrates of late-life minor depression. A quantitative magnetic resonance imaging study

To examine the neuroanatomical correlates of late-life minor depression using magnetic resonance imaging.

Cross-sectional quantitative magnetic resonance imaging study of elderly patients with minor depression and age-matched controls.

Patients and controls were recruited from the community through advertisements to the Section of Geriatric Psychiatry, University of Pennsylvania, Philadelphia.

Our sample included 18 subjects diagnosed as having minor depression using the modified Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, research criteria and 31 controls without depression. Patients were free of other central nervous system disease and both groups had comparable degrees of medical comorbidity.

All images were acquired on a 1.5-T scanner and absolute and normalized quantitative measures of global and focal brain and cerebrospinal fluid volumes were compared between groups.

Prefrontal lobe volume was significantly smaller in the group with minor depression (P = .002) compared with controls after controlling for age, sex, and age by sex interactions. More global measures of brain and cerebrospinal fluid volumes were comparable in both groups.

These data suggest that focal prefrontal atrophy may provide an important neuroanatomical substrate in late-life minor depression.