Objective: The aims of this study were to examine the daily affective experiences of patients with Parkinson disease (PD) and to determine their association with daily events and motor symptoms. Specifically, it was intended to test the hypothesis that PD, even in the absence of depression, is associated with anhedonia.
Method: Nondepressed male subjects with PD (N=24) and a comparison group of healthy elderly males (N=23) completed daily affect rating scales and, for the patients with PD, a supplemental self-assessment questionnaire of PD-related symptoms for 4 consecutive weeks. The effect of daily events and PD-related symptoms on daily affect was examined using linear and logistic mixed regression models.
Results: Overall, patients with PD reported significantly less positive and more negative affect than healthy peers over time. There were similar, and expected, associations between negative events and affect in both groups. Although patients with PD reported far fewer positive events than control subjects, they reported as great an improvement in affect in response to them. Regarding self-reported PD-related symptoms, only increasing severity of core motor symptoms was independently associated with worse affect.
Conclusions: Although the conclusions of this study are tempered by a comparison group that is not optimal, our results suggest that patients with PD do not demonstrate anhedonia in response to positive life events. The gross intergroup difference in daily events suggests the potential value of interventions that emphasize daily engagement in positive experiences to improve positive affective tone.