Somatoform Disorders in Parkinson’s Disease and Dementia with Lewy Bodies Evidence Underlying Psychotic Traits

Somatoform disorders have only recently been described in Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). Of 1,210 patients with neurodegenerative diseases referred to our institutions from 1999, 488 were diagnosed with PD, 415 with Alzheimer’s disease, 162 with DLB, 48 with progressive supranuclear palsy, 48 with multiple system atrophy, and 49 with frontotemporal dementia. Rates of somatoform disorder were considerably higher in DLB (18%) and PD (7.5%) than in any other group (0–2%). Somatoform disorders in PD and DLB were characterized by motor and non-motor patterns with bizarre presentations, and were often accompanied by catatonic signs (41%). In 77%, they preceded PD motor signs by 6–120 months, and in 86%, they were recurrent at follow-up. In 91%, there was preceding or concomitant hypochondriasis. Global cognitive decline was greater in PD with somatoform disorder than without (p