Disease-Related Variables and Depression Among Iranian Patients with Parkinson Disease

BACKGROUND: The factors affecting the correlation between Parkinson disease (PD) and depression have remained unclear. OBJECTIVES: We assessed the prevalence of depression among patients with PD and the association between PD-related variables and depression severity. PATIENTS AND METHODS: This is a cross-sectional study performed in Kermanshah Province of Iran. Sampling was based on recruitment of subjects according to inclusion and exclusion criteria. Patients with confirmed Parkinson disease who were referred to clinics of Kermanshah University of Medical Sciences participated in this study. Depression was evaluated with Beck Depression Inventory-II (BDI-II). Clinical characteristics of PD, including tremor, rigidity, impaired posture, loss of autonomic movement, changes in speech and handwriting, masked face, and hyposmia were indexed. Anhedonia was assessed with Farsi version of Snaith-Hamilton Pleasure Scale. Data were collected between April 2010 and March 2014. RESULTS: A total of 350 patients (52.9% men and 47.1% women) participated in this investigation. Female gender (36.5% in women vs. 13.0% in men, P < 0.0001), impaired posture (27.2% in affected individuals vs. 18.8%, P = 0.002), masked face (39.0% vs. 5.2%, P < 0.0001), and hyposmia (48.7% vs. 21.0%, P = 0.001) were associated with higher susceptibility to profound depression. Lower scores of all domains of Farsi version of Snaith-Hamilton Pleasure Scale (including interest/pastimes, social interaction, sensory experience, and food/drink) were related to more severe depression (P < 0.0001 for all subscales). Severe and profound depression was found in 44% of the participants. CONCLUSIONS: This study estimated that the prevalence of major depression among Iranian individuals with PD living in Kermanshah as 44%. Major determinants of depression were female gender, rigidity, impaired posture, masked face, hyposmia, and anhedonia.