Apathy is not only associated with cognitive impairment, but also with impaired daily functioning, caregiver burden and distress, medication noncompliance, and increased mortality. Differentiating apathy and depression, understanding their unique effects, and appropriately identifying apathy symptoms in patients have robust implications for the development of neuropsychological models of these effects in PD as well as practical implications in guiding improvements to patient care and enhancing quality of life in patients and caregivers.

Due to controversy regarding the influence of apathy on quality of life (QoL), the authors examined the independent influence of apathy, depression, and trait anxiety in a nondemented sample of patients with Parkinson disease (PD). Participants (N=107) completed standard self-report measures of QoL and mood/motivation. Analyses investigated the contribution of these measures and empirically derived factor scores on QoL. QoL was predicted by trait anxiety, dysphoria, and decreased interest, with no independent contribution of apathy. Different patterns emerged with respect to domain-specific QoL, with trait anxiety being the strongest predictor across most domains. Anxiety was most widely related to QoL in PD, with minimal contribution of apathy. Future studies should examine different roles of PD mood/motivation symptoms on caregiver QoL.

The program may hold promise as an effective nonpharmacological intervention for apathy in PD. Implications and future directions are discussed. Randomized controlled trials are needed.