Anxiety and depression were measured using the Patient-Reported Outcome Measurement Information System (PROMIS-29) in 615 PD patients (67±9 years, 64% male, motor-UPDRS 24±13) during sequential visits between 2014 and 2022. Based on T-scores, PD patients were categorized into 3 subgroups (no, mild, or moderate/severe) for both depression and anxiety at baseline and again 2 and 4 years later, based on the same criteria.

At baseline, 74% of patients had no depression, 16% mild, 10% moderate/severe; 69% had no anxiety, 16% mild, 15% moderate/severe. Over time, the proportion of patients without depression or anxiety decreased (2 years: depression 69%, anxiety 59%; 4 years: depression 64%, anxiety 55%), while the frequency of patients with some degree of depression or anxiety increased accordingly. For both depression and anxiety, most patients in the non-symptomatic (67-82%) and moderately/severely affected groups (55-64%) did not change category at follow-up. Patients with mild depression at baseline split evenly into all 3 categories after 2 years, with more shifting towards moderate/severe depression after 4 years. Likewise, the proportion of patients with mild anxiety that were re-categorized as moderate/severe anxiety increased from 24% after 2 years to 41% after 4 years. 

The prevalence of both depression and anxiety in a large PD cohort increases over time. Most patients with either no or moderate/severe depression or anxiety remain in their baseline category. In contrast, patients with mild depression or anxiety at baseline show more variability in the severity of their mental health symptoms over time.