Am J Psychiatry 1996; 153:1460-1463
Copyright © 1996 by American Psychiatric Association
d-fenfluramine-induced prolactin responses in mania: evidence for serotonergic subsensitivity
JH Thakore, V O'Keane and TG Dinan
Department of Psychological Medicine, St. Bartholomew's Hospital, London, United Kingdom.
OBJECTIVE: The authors examined serotonergic-mediated prolactin release in
bipolar mania, using d-fenfluramine as a probe. METHOD: Hospitalized
patients with bipolar disorder, currently manic, were matched for age and
sex to healthy comparison subjects. Each group consisted of nine subjects
(seven men and two women). After an overnight fast, all subjects had an
intravenous cannula inserted into a forearm at 8:30 a.m., and baseline
blood samples for determination of prolactin and cortisol levels were
drawn. d-Fenfluramine (30 mg p.o.) was then administered; plasma prolactin
levels were measured 15 minutes before d- fenfluramine was given,
immediately before, and 60, 120, 180, 240, and 300 minutes afterward.
RESULTS: Baseline serum cortisol levels were higher in the bipolar manic
subjects than in the comparison subjects, although baseline prolactin
levels were similar in the two groups. The plasma prolactin responses to
d-fenfluramine of the bipolar manic subjects were significantly lower than
those of the comparison subjects. CONCLUSIONS: Bipolar mania appears to be
associated with a state of decreased serotonergic responsivity similar to
that found in unipolar depression.
