Psychophysiological changes during pharmacological treatment of patients with obsessive compulsive disorder

Twelve patients with obsessive compulsive disorder were studied with psychophysiological measures during a randomised, double-blind placebo-controlled drug trial. Significant clinical improvement followed six weeks of treatment with the tricyclic antidepressant clomipramine, but was not evident after an equal period of treatment with the monoamine oxidase inhibitor (MAOI) clorgyline. Compared to placebo, both drugs reduced skin conductance indices of baseline arousal, but only clomipramine reduced skin conductance and heart rate responses to loud tones and tonic and phasic skin conductance responses in a two-flash discrimination task. This suggests that reductions in autonomic responses to important and/or aversive stimuli may be critical to clinical improvement in obsessive compulsive disorder.