Psychiatric comorbidities in patients with Parkinson disease and psychosis

To determine the prevalence and impact of comorbid psychiatric disturbances in Parkinson disease (PD) patients with psychosis.

Subject data were derived from a research database of 116 PD patients participating in standardized motor, cognitive, psychiatric, and caregiver assessments.

There were 25 patients (22%) with psychosis manifest as hallucinations (n = 9), delusions (n = 1), or hallucinations and delusions (n = 15) and 25 patients (22%) who had no current or past psychiatric comorbidities (PDN). In the psychotic group, 44% had psychosis only (PSY), and 56% had psychosis plus at least one other comorbid psychiatric disturbance (PSY+), including depressive disorders (71%), anxiety disorders (21%), apathetic syndromes (14%), and delirium (14%). There were no differences in age, sex, education, or age onset or duration of PD among the PSY, PSY+, and PDN groups. Both psychotic groups had greater motor, functional, and frontal cognitive deficits and increased caregiver burden scores relative to PDN. PSY+ showed greater global and selective cognitive deficits compared to PDN. Psychosis was a primary predictor of caregiver burden, whereas depressive symptoms indirectly enhanced motor impairments.

Nonpsychotic psychiatric disturbances, especially affective disturbances, are common comorbidities in PD patients with psychosis and warrant clinical attention to reduce morbidity and caregiver distress.