Hedonic deficits in Parkinson's disease: is consummatory anhedonia specific?

Anhedonia, the lowered ability to experience pleasure, is one of the non-motor symptoms of Parkinson's disease (PD) that is underdiagnosed and consequently undertreated. Few studies have investigated anhedonia in PD by taking into account the influence of socio-demographic variables and versus a control group composed of patients with a pure motor neurologic disease other than PD. The aim of this study was to investigate hedonic deficits in patients with PD compared to a control group of patients with non-Parkinson motor neurologic disease (OND), matched for age, gender, level of education, and inpatient/outpatient status. Distinctions between anticipatory and consummatory anhedonia and between endogenomorphic and non-endogenomorphic depression were taken into account.

The study population comprised 49 PD patients and 40 subjects with OND. Anhedonia was rated by using the anticipatory [Temporal Experience Pleasure Scale (TEPS)-ANT] and consummatory (TEPS-CONS) subscales of the TEPS and two subscales extracted from the revised Physical Anhedonia Scale (PAS), measuring physical anticipatory (PAS-ANT) and physical consummatory (PAS-CONS) anhedonias. The Snaith-Hamilton Pleasure Scale (SHAPS) and the Beck Depression Inventory-II (BDI-II) were also used together with a subscale extracted from the BDI-II (ENDO-BDI-II) for the diagnosis of endogenomorphic depression. Statistical analyses were performed on the whole group and on the PD group.

As hypothesized, several anhedonia scores varied with age and gender in the whole population or in the PD group. On univariate or multivariate analyses, only PAS-CONS was specific for PD and only SHAPS scores differed between depression subtypes in the whole population or the PD group.

This study suggests that physical consummatory anhedonia could be specific to PD subjects.