Abstract
The patient was a 64-year-old woman with a 31 year history of schizophrenia well managed with pimozide. She was changed from pimozide to aripiprazole 3 years previously, starting on 10 mg day−1 for 5 months then increased to 15 mg day−1. She was in the habit of putting AUD$1-2 on the poker machines but 6 months after the increased dose of aripiprazole, she developed an irresistible urge to gamble, losing up to AUD$700 per session, which she could ill afford. She also experienced a compulsion to eat, gaining 9 kg. The patient described her experiences as ‘I just wanted to keep putting money in, it was an urgency. I would go high……and I seemed to lose all reason. I also could not say no to food, especially sweets and cakes’. She denied any compulsive shopping or hypersexuality and she was not taking any other medication.
The urge to gamble stopped 1 month after she was switched to ziprasidone 40 mg bd and she also lost 2 kg in weight. The patient was asked if she could restart aripiprazole in an ABA design to show whether the antipsychotic was indeed the cause of her gambling, but she refused. The patient did not have a previous history of drug or alcohol abuse or novelty-seeking behaviour and does not suffer from Parkinson's disease.
The onset of dopaminergic drugs, for example L-dopa, pergolide, cabergoline, pramipexole and ropinirole, in the treatment of Parkinson's disease, led to the observation of compulsive behaviours such as gambling, hypersexuality, shopping, eating, substance abuse and punding. These behaviours are reward based and are reinforced by dopaminergic stimulation via the mesolimbic tract and involve the dopamine 3 (D3) receptor [1].
A literature search using PubMed, PsychInfo and Embase and the manufacturer's data base did not find a previously reported case of compulsive behaviour associated with aripiprazole, although there are blogs in which patients on this drug describe pathological gambling. There are two cases in the literature in which another antipsychotic, quetiapine, at doses of 200 mg day−1 precipitated stereotyped behaviour in parkinsonian patients who were also on cabergoline and L-dopa, and whose compulsions stopped when quetiapine was reduced to 100 mg and 50 mg day−1, respectively [2]. Aripiprazole is a novel antipsychotic with D2-blocking properties in hyperdopaminergic and D2 agonist activity in hypodopaminergic states [3]. The present case suggests that in some patients aripiprazole may also have D3 agonist activity.
The present case also suggests that clinicians should ask about compulsive behaviour with this antipsychotic, because patients may be reluctant to disclose this voluntarily.