Somatization in Parkinson's disease: a systematic review

The current systematic review study is aimed at critically analyzing from a clinimetric viewpoint the clinical consequence of somatization in Parkinson's Disease (PD). By focusing on the International Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive electronic literature research strategy on ISI Web-of-Science, PsychINFO, PubMed, EBSCO, ScienceDirect, MEDLINE, Scopus, and Google Scholar databases. Out of 2.926 initial records, only a total of 9 studies were identified as clearly relevant and analyzed in this systematic review. The prevalence of somatization in PD has been found to range between 7.0% and 66.7%, with somatoform disorders acting as clinical factor significantly contributing to predict a progressive cognitive impairment. We highlighted that somatization is a highly prevalent comorbidity affecting PD. However, the clinical consequence of such psychiatric symptom should be further evaluated by replacing the clinically inadequate diagnostic label of psychogenic parkinsonism with the psychosomatic concept of persistent somatization as conceived by the Diagnostic Criteria for Psychosomatic Research (DCPR).