Anhedonia and cognitive impairment in Parkinson's disease: Italian validation of the Snaith-Hamilton Pleasure Scale and its application in the clinical routine practice during the PRIAMO study.

Objective: To assess the psychometric properties of the Italian version of the Snaith-Hamilton Pleasure Scale (SHAPS) and to study the relationship between anhedonia, depression and cognitive impairment in patients with Parkinson's disease (PD).

Methods: The SHAPS (14 items) was translated into Italian and pre-tested in a pilot study. Two items evaluating physical anhedonia related to sexual issues were added. The Italian version of SHAPS was validated in 274 consecutive PD patients, divided into patients with major depression according to DSM-IV criteria (dPD) and patients without depression (nPD), and in healthy subjects. To test the feasibility of the instrument and to determine whether clinical data affect anhedonia, we also administered SHAPS to 1307 patients with different types of parkinsonism.

Results: The Italian SHAPS proved to be easy to understand as regards the question and answer modes. Intraclass coefficient for test-retest reliability was 0.65 for the total score. KR index was 0.61. ANOVA of the SHAPS total score revealed that scores were higher in dPD patients than in healthy controls and nPD (p<0.05). In the 1307 patients with various types of parkinsonism, the SHAPS data showed that anhedonia was related to age, type of parkinsonism, apathy, depression and cognitive impairment. Anhedonia was correlated with frontal dysfunctions in supranuclear palsy and PD patients (r=-0.682 and -0.264 respectively, p<0.05).

Conclusion: The Italian version of the SHAPS is a reliable tool with which to assess anhedonia in patients with PD and other forms of parkinsonism.