Characteristics, correlates, and assessment of psychosis in Parkinson disease without dementia.

INTRODUCTION

Considering that psychosis in Parkinson disease (PD) is associated with worse outcomes, including dementia, we aimed to study the characteristics, correlates, and assessment of PD psychosis in those without dementia.

METHODS

101 PD subjects without dementia (Montreal Cognitive Assessment ≥21/30) were recruited to participate in a study of neuropsychiatric symptoms in PD. This study included a baseline standard neurological exam and common PD symptom assessments. Using the Scale for the Assessment of Positive Symptoms (SAPS) and separate assessment of visual illusions and sense of presence, NINDS-NIMH criteria for PD psychosis were applied.

RESULTS

Of the 33 (32.7%) PD subjects who met diagnostic criteria for psychosis in PD, visual illusions were most common (72.7%), followed by visual hallucinations (39.4%). Adjusted for presence of REM sleep behavior disorder (RBD) (p = 0.097), use of dopamine agonists (OR = 3.7, p = 0.012) and greater autonomic symptom burden (OR = 1.1 (per 1-unit change in score on SCOPA-AUT), p = 0.012) were associated with greater risk of psychosis. Use of dopamine agonists (OR = 5.0, p = 0.007), higher MDS-UPDRS Part II score (OR = 1.1, p = 0.010), and presence of RBD (OR = 4.8, p = 0.012) were independent predictors of visual hallucinations and visual illusions. MDS-UPDRS item 1.2 score ≥1 had highly correlated with the SAPS score (r = 0.65, p < 0.0001), but was 42% sensitive and 96% specific for identifying psychosis.

CONCLUSION

This study confirms the association between dopamine agonists and psychosis in PD patients without dementia. The association of RBD, autonomic symptoms, and MDS-UPDRS Part II scores with psychosis underscore its link to brainstem dysfunction and greater PD motor symptom severity.