Pet killing as a manifestation of impulse control disorder secondary to pramipexol

Impulse control disorders are frequent in Parkinson disease and are commonly associated with dopamine agonists intake. Typical manifestations include punding, hypersexuality, pathological gambling, and other compulsive behaviors. Symptoms often promptly disappear when dopamine agonists are discontinued, but if the origin is misinterpreted, symptoms may become a problem. We here report the case of a patient with juvenile Parkinson disease treated with 4.5 mg/d of pramipexol, who developed the need to adopt cats. He adopted almost 50 of them, but after he adopted them, he felt the need to kill them. The case became well known, and he became depressed and isolated. He was admitted to a psychiatric hospital and thought that he was a psychotic. However, when pramipexol was replaced by levodopa, the symptoms disappeared. This case illustrates the wide range of manifestations of impulse control disorders and warrants the inclusion of violent behaviors among them.