Paraphilias and paraphilic disorders in Parkinson's disease: A systematic review of the literature.

Paraphilias are intense urges or behaviors involving non-normative sexual interests. The newly approved diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) have established that, although paraphilias should not be regarded as inherently pathological, they ought to be qualified as paraphilic disorders if resulting in distress, impairment, or harm to the affected individual or others. Recent evidence documents that both phenomena can emerge as relatively uncommon iatrogenic consequences in Parkinson's disease (PD) patients. To outline the clinical characteristics of paraphilias and paraphilic disorders in PD patients, we summarized the available evidence on these phenomena. The review encompasses all studies on paraphilias in PD patients identified by a search on the Pubmed and Scopus online databases through May 2014. Twenty-two case reports on a total of 31 PD patients with paraphilias or paraphilic disorders were identified. These phenomena were typically associated with dopaminomimetic treatment (with a mean levodopa-equivalent daily dose of 1,303 ± 823 mg/d) in male patients with motor complications, young age at PD onset, and long disease duration. Paraphilias were highly concomitant with impulse-control disorders or dopamine dysregulation syndrome. Although evidence on paraphilias and paraphilic disorders in PD patients remains anecdotal, available data point to these phenomena as likely sequelae of high-dose dopaminomimetic treatment. Accordingly, the intensity of paraphilic urges is typically attenuated by the reduction of dopaminomimetic doses, sometimes in association with atypical antipsychotics. Failure to recognize paraphilic disorders may significantly impair the relational functioning of the affected PD patients. Practitioners should routinely inquire about paraphilias during their clinical assessment of PD patients.