Researchers of this longitudinal study followed 105 people with Parkinson’s disease but without dementia over 3 years to better understand Parkinson’s disease psychosis (PDPsy) and its relationship to cognition. Psychosis was common and increased over time, with prevalence rising from about 31% at baseline to nearly 39% by year 3. Minor hallucinations, especially visual illusions, were the most frequent symptoms. Many psychotic events were early or milder in form rather than severe hallucinations or delusions. In the clinical analysis, depressive symptoms stood out as the strongest independent predictor of psychosis. Broader measures such as age, disease duration, overall motor severity, and global cognitive impairment were not significant once other factors were considered.
On the cognitive side, the clearest association with psychosis was worse performance on Trail Making Test B minus A, a measure tied to executive function and attention. That suggests PDPsy in this relatively early-stage, non-demented Parkinson’s cohort may be linked less to overall cognitive decline and more to specific problems with attention and mental flexibility. The authors conclude that depression and executive/attentional dysfunction may be early warning signs for developing or worsening psychosis in Parkinson’s disease. They recommend that clinicians monitor both closely. They also note important limitations, including attrition over time, exclusion of passage hallucinations, and the fact that the sample skewed toward patients with better cognition and higher education, which may limit how broadly the findings apply.
Reference: Flanigan JL, Harrison MB, Patrie JT, et al. Clinical and cognitive features associated with psychosis in Parkinson’s disease: a longitudinal study. Front Aging Neurosci. 2024;16:1463426. doi: 10.3389/fnagi.2024.1463426.
Link: https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2024.1463426/full
