Lab. Hetem et al., D-FENFLURAMINE REDUCES ANXIETY INDUCED BY SIMULATED PUBLIC SPEAKING, Brazilian journal of medical and biological research, 26(9), 1993, pp. 971-974
To further explore the role of serotonin (5-HT) in anxiety, 28 healthy
volunteers received in a double-blind study d-fenfluramine (30 mg, p.
o.) or placebo, and were submitted to a simulated public speaking test
(SPS), consisting of speaking in front of a video camera. The SPS ind
uced significant increases in subjective anxiety evaluated by the visu
al analogue mood scale of Norris [MANCOVA, F(1.66,39.93) = 8.51, P<0.0
01], as well as in systolic blood pressure [F(3,72) = 5.70, P = 0.001]
and in heart rate [F(3,72) - 3.95, P = 0.012]. The drug decreased the
anxiety factor [F(1,23) = 5.2 1, P = 0.032], without significantly af
fecting physical sedation, mental sedation or other feelings and attit
udes. Also, the physiological measurements were not significantly chan
ged by d-fenfluramine. Reported evidence shows that d-fenfluramine rel
eases 5-HT from nerve endings and blocks 5-HT reuptake, indirectly sti
mulating postsynaptic 5-HT receptors. Therefore, the present results i
ndicate that 5-HT inhibits the neural substrate of SPS-induced anxiety
.