Aberrant sexual behaviours in Parkinson’s disease during dopaminergic treatment

Although modifications in sexual behaviour are a well-known occurrence during dopaminergic therapy in Parkinson’s disease (PD) , they can also assume connotations of serious psychiatric disorders such as paraphilias and other aberrant sexual behaviours, to date scarcely reported in the literature. These aberrant sexual behaviours (ASB) can include criminal, antisocial or immoral actions such as rape, paedophilia, incest, zoophilia, frotteurism, exhibitionism, etc. Less dramatically, aberrant but not criminal behaviours such as excessive masturbation, buying, collecting pornographic material or voyeurism, can be observed. We report on nine consecutive patients with PD, according to clinical criteria [7], observed during an 11-year period that developed ASB whilst undergoing dopaminergic treatment. Invariably the presence of ASB was spontaneously reported by the spouse or other relatives, referring to dramatic events including rape, incest, paedophilia, zoophilia, frotteurism, exhibitionism, obsessive masturbation, obsessive buying, collecting and viewing of pornographic material, voyeurism and hyperlibidinous behaviour. Records were prepared for all patients with regard to clinical features, dopaminergic treatment at ASB onset, Hoehn and Yahr staging [6], Unified Parkinson’s Disease Rating Scale (UPDRS) motor scale , Global Deterioration Scales (GDS) [13], Mini Mental State Examination (MMSE) , neuroimaging (MRI or CT), pre-existence of drug-induced minor psychiatric disorders and motor complications associated with levodopa therapy. The characteristics of the patients are summarised in Table 1. Eight patients presented with signs of motor complications associated with levodopa therapy, and in all of these patients the ASB took place in the ‘‘on’’ period. The occurrence of ASB was mainly manifested following the introduction or increment of a dopamine agonist (more frequently pergolide) and only in one case with levodopa alone. During the period of our observations, pergolide was actually the most commonly prescribed dopamineagonist in our clinical practice, although ergot and non-ergot derivatives were prescribed equally. In the first 7 patients (behaviour with criminal connotations) the drug in question was immediately reduced or suspended and clozapine introduced (with the exception of patient 7 where quetiapine was added instead of clozapine). In patients 8 and 9 (aberrant, but not criminal behaviour), as a first step a reduction/withdrawal of the dopamine agonist was attempted: this proved satisfactory in patient 9, with disappearance of ASB, but was not sufficient in patient 8, thus rendering necessary the subsequent addition of clozapine. In no case was dopaminergic treatment totally suspended. Over an 11-year period of observation, the manifestation of ASB in nine PD patients during dopaminergic therapy, while the literature presents only rare anecdotal reports [1, 2, 4, 8, 10, 14], suggests that the phenomenon is likely to be largely underestimated. Although these types of behaviour are often punishable by law and may at times lead to imprisonment, in our case series, the occurrence of ASB mainly took place in a family setting and no types of legal proceedings were undertaken by relatives, with the exception of one patient. Previous studies reported that sexual disorders, such as hypersexuality, are increasingly observed in advanced PD [11] or in parkinsonian patients treated with highdoses of dopaminergic drugs . On the contrary, our observations seem to illustrate a wide sphere of conditions in which ASB may be manifested. Indeed, only two of our patients (patients 1 and 8) were at an advanced stage of PD. The core of our study was represented by six patients (patients 2–6 and 9): all presented with initial motor complications associated with levodopa therapy, although none had a clinical history of psychiatric or sexual conduct disorders, with the A. Cannas Æ P. Solla Æ G.L. Floris G. Serra Æ P. Tacconi Æ M.G. Marrosu Centro per i Disordini del Movimento Dipartimento di Scienze Cardiovascolari e Neurologiche Sezione Neurologia University of Cagliari Cagliari, Italy