Parkinson's disease and obsessive-compulsive phenomena: A systematic review

Objective: To review the literature regarding the occurrence of obsessive-compulsive disorder (OCD), obsessive-compulsive symptoms (OCS), and related personality traits in Parkinson's disease (PD). Methods: A PsycInfo, Medline, Embase and Lilacs search of English, French, Spanish and Portuguese-language publication was conducted. The search terms used were Parkinson's and any of the textual words: obsessive, compulsive or personality. Some of the terms were also truncated to improve the search sensitivity. Data concerning personality traits in PD were also considered. Results: The literature concerning OCD, OCS and a particular "parkinsonian personality" in PD is still contradictory. One of the main problems identified was the diversity of instruments used to assess obsessive-compulsive symptoms or traits. However, some studies have highlighted the correlation of motor symptoms asymmetry and specific OCS or personality traits. Other relevant data of the selected studies are also presented and discussed. Conclusion: The available data have critical methodological problems. Although it is well known that PD and OCD share dysfunction of the frontostriatal circuitry, the relationship between them has to be confirmed.