Clozapine-responsive cluster headache

Headaches are commonly associated with various psychiatric disorders. The comorbidity of migraine and psychiatric disorders has been well documented. Here we present a case of schizophrenia with comorbid headache treated with clozapine. The patient's headache fulfilled the diagnostic criteria for cluster headache (CH). To our knowledge this is the first report of CH responding to clozapine therapy. The relationship of headache and psychiatric disorders is a matter of debate and there has been very little research on the aspect of causality or direction of causation. The response of both the conditions to a serotonin-dopamine antagonist such as clozapine might be important in giving newer insights into the pathogenesis of these disorders. It also has the clinical implication of being useful in patients with dual diagnosis.