Symptoms and physiologic manifestations in obsessive compulsive patients before and after treatment with clomipramine

Anxiety and hyperarousal constitute important aspects of obsessive compulsive disorder (OCD). This study examined the effects of clomipramine on symptoms, arousal-related physiologic states, and stress reactions in OCD patients.

Twenty-five OCD patients were randomly assigned to a clomipramine or placebo group and were assessed for 10 weeks using a double-blind parallel design. They were assessed clinically with the Yale-Brown Obsessive Compulsive Scale, the National Institute of Mental Health Global Obsessive-Compulsive Scale, the patient- and investigator-rated Global Improvement Scales, and the Hamilton Rating Scale for Depression. Prior to treatment, and again during the last day of medication, physiologic states (heart rate, respiration, skin conductance, blood pressure, and EMG) were measured at rest and during both nonspecific (psychomotor tasks) and pathology-specific (visualization) stressors.

Patients taking clomipramine, but not those taking placebo, improved significantly on all clinical measures. With the exception of heart rate, treatment did not affect resting physiologic states. Heart rate increased in patients taking clomipramine and decreased in patients taking placebo. Autonomic reactivity to nonspecific and to pathology-specific stressors was attenuated by clomipramine, but not by placebo.

Clinical improvement on clomipramine treatment was independent of the physiologic state of the patients and was not associated with autonomic down-regulation. The attenuation of autonomic reactivity to stressors appears not to be pathology-specific but may reflect either a direct pharmacologic effect of clomipramine on the autonomic nervous system or a heightened indifference to psychological stressors in general.