Personality change in Parkinson's disease patients: chronic disease and aging.

Parkinson's disease patients (N = 41, mean age = 65 years) were described by themselves and their spouses as they were presently and before their illness using the Adjective Check List. Equivalent self- and spouse descriptions were obtained from the members of a matched community sample (N = 96). Descriptions of patients and their spouses converged, both reporting sharp, pervasive (e.g., on all of the Big Five dimensions), and uniformly negative change in personality. Similar, but much less marked change was found in the community sample. The data as a set suggest that the reported changes in the patients were veridical and that their magnitude was primarily the result of the disease rather than aging. Evidence of continuities in personality (for example, differential stability) was also noted. We argued that the illness accelerated and intensified changes normally expected in later life.