Am J Psychiatry 1997; 154:970-975
Copyright © 1997 by American Psychiatric Association
Brainstem evoked response abnormalities in late-life depression with vascular disease
B Kalayam, GS Alexopoulos, FE Musiek, T Kakuma, A Toro, D Silbersweig and RC Young
Department of Psychiatry, Cornell University Medical College, New York. bkalayam@westnyh.med.cornell.edu
OBJECTIVE: The purpose of this study was to examine whether the brainstem
evoked responses of geriatric depressed patients with vascular disease show
greater changes in wave V latency after increased stimulation than do
responses of geriatric depressed patients without vascular disease and
elderly comparison subjects with and without vascular disease. METHOD:
Geriatric patients with unipolar depression (N = 53) were recruited from a
university psychiatric hospital. Elderly comparison subjects (N = 23) were
recruited through advertisements. All subjects were assessed for depressive
symptoms, cognitive performance, overall medical burden, vascular disease,
and disability. Brainstem evoked response was elicited at stimulation rates
of 11.4 and 80.0 clicks/sec. RESULTS: The interaction between depression
and vascular disease had a significant effect on change in wave V latency.
This effect was synergistic, more than an additive effect. Post hoc
comparisons showed that the depressed patients with vascular disease had
greater changes in wave V latency that did the depressed patients without
vascular disease, comparison subjects with vascular disease, and comparison
subjects without vascular disease. Linear discriminant function analysis
showed that 82% of the subjects with abnormal changes in wave V latency
(sensitivity: 75%, specificity: 81%) could be identified on the basis of
ratings for depression and vascular disease. CONCLUSIONS: Demyelination
afflicting the pons and mesencephalon may explain the greater change in
wave V latency for the brainstem evoked response in depressed patients with
vascular disease. Further studies combining brainstem evoked response with
brain imaging may determine whether depression develops only after vascular
disease leads to demyelination.
