Paraphilias are disorders of abnormal sexual interest that present with recurrent abnormal sexual fantasies, urges or behaviours. Hypersexuality and paraphilia are known complications of treatment with dopamine agonists (Reference Shapiro, Chang, Munson, Okun and Fernandez1,2).

We report the case of a 52-year-old single male who had difficulties in relationships, anxiety and mild depressive symptoms. He had reported that he was sexually abused by his own father when he was a child. He never married, but reported several longstanding heterosexual relationships. He reported occasional homosexual encounters not associated with any guilt or shame. The patient presented a sudden worsening of anxiety and dysphoria due to problems at work. At first he described himself as anxious, but later confessed to paraphilic behaviour in the form of wearing makeup, dressing in women's underwear and connecting to erotic heterosexual videochat over the Internet. The exacerbation of paraphilic interest and behaviour was triggered by taking 1 tablet/day of Pramipexole 0.7 mg (Mirapexin^©) for 6 months, as prescribed by the neurologist for the treatment of moderate restless legs syndrome (RLS). Before taking this drug he used to chat 1–3 h/day, 2–3 days/week and was able to resist the impulse to enjoy leisure, sports and social activities with his many friends and his female mates. When he came to us he was spending 5–7 h/day, 5–7 days/week in chatting, his social life had vanished and he was about to be dismissed from his work. During the first psychiatric consultation it was prescribed as a relatively low dose of Paroxetine (10 mg/day) in order to reduce anxiety and dysphoria. When found the problem with cross-dressing, it is proposed to increase the dose of Paroxetine up to 20 mg/day to reduce hypersexuality. However, the patient responded that he did not want to reduce sexual desire but only the discomfort due to feelings of loss of control, so he did not accept more than 10 mg/day of Paroxetine.

At this point, the patient was not suffering major depressive syndrome, neither severe anxiety nor elation, so we suspected that Pramipexole could have worsened the basal severity of his paraphilia. We stopped Pramipexole treatment and alleviated the RLS with Clonazepam (1 mg/day). The mood improved and 1 month later, anxiety and dysphoria were gone. The patient reduced the amount of time spent in chatting and returned to his previous level of social and occupational function.

Pramipexole stimulates D2 and D3 receptors of dopamine in the brain. This drug, like l-dopa, is prescribed to treat both Parkinson's disease (PD) and RLS. The RLS has a prevalence of 4–10%. Although some studies reported higher rates of depression and anxiety in patients with RLS, it is unclear whether these conditions are coexistent or the result of an interruption of sleep (Reference Winkelman, Finn and Young3). Some of Pramipexole-related adverse events are the worsening of motor symptoms, psychiatric symptoms such as delusions and hallucinations, confusional states and drowsiness. According to some case reports, the treatment with a dopaminergic drug might start, reveal or worsen a patient's latent paraphilia (Reference Munhoz, Fabiani, Becker and Teive4,Reference Nielssen, Cook, Joffe, Meagher and Silberstein5); the patient may experience the condition as a problem for the first time.

To our knowledge, this is the first report of a first diagnosis of paraphilia in a non-parkinsonian patient treated with a dopaminergic drug before the onset of old age. A sudden paraphilia, hypersexuality, pathological gambling and other impulse control disorders are well-described complications of PD and RLS that are being treated with dopamine agonists (especially if these are selective to D3 receptors like ropirinole and pramipexole). As in PD, RLS patients should be cautioned about potential behaviours that may occur with the use of dopaminergic medications and consider using Clonazepam for the treatment of RLS.