Psychiatric symptoms in progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is an unusual neurodegenerative disorder that superficially resembles Parkinson's disease (PD). It is characterized by gaze palsy, bulbar signs, parkinsonian signs, and mental changes. While mental changes are a frequent finding, they have, with the exception of dementia, been poorly defined. In this study, 19 patients with PSP were evaluated psychiatrically and compared with 42 patients with PD. Fifty-two percent of the patients had some degree of dementia, as measured by the Mini-Mental State Exam. Eight (42%) of the PSP patients had other psychiatric diagnoses, mostly relatively mild depression or anxiety, though two patients had more severe depression. Six (32%) patients had pathologic laughing or crying, and four of these had a psychiatric diagnosis other than dementia. The PSP patients did not differ from the PD patients on measures of depression or anxiety and did not have a greater rate of formal psychiatric diagnoses. This study confirms previous reports of dementia as a common feature of PSP. It further suggests that psychiatric disturbances, while common, are generally relatively mild, though more serious psychiatric illness may be seen.