Clinical, magnetic resonance imaging and endocrinological differences between delusional and non-delusional depression in the elderly.

Objective: To investigate neuroradiological, endocrinological and clinical differences between delusional and non-delusional depression.
Design: A cross-sectional study of depressed subjects.
Setting: Melbourne, Australia.
Participants: Sixty-one subjects (inpatients) over the age of 55 meeting DSM-III-R criteria for major depression of whom 22 had delusional subtype of depression.
Measures: Clinical assessment, including documentation of vascular risk factors. Cognitive assessment by the Cambridge Cognitive Examination (CAMCOG). Magnetic resonance imaging (MRI) scans were performed on a 0.3 Tesla scanner with temporal lobe atrophy, periventricular lesions (PVL) and deep white matter lesions (DWML) rated visually on 4-point scales. A standard 1 mg dexamethasone suppression test (DST) was performed.
Results: Subjects with delusional depression had significantly more vascular risk factors than those without delusions. There were no differences in measures of temporal lobe atrophy, PVL, DST results or cognitive test scores, though there was a non-significant trend for DWML to be more prevalent in those with delusions. Delusional depression was associated with a shorter duration of history and more frequent treatment with ECT.
Conclusions: The increase in vascular risk factors and trend towards greater DWML on MRI suggests an organic contribution to delusional depression in the elderly. In contrast to some previous reports, we found no differences in cortical MRI appearance or neuroendocrine measures between groups.