Abstract
Introduction The Geriatric Depression Scale (GDS) is commonly used to assess depressive symptoms, but its psychometric properties have never been examined in Italian people with Parkinson's disease (PD). The aim of this study was to study the reliability and validity of the Italian version of the GDS in a sample of PD patients. Methods The GDS was administered to 74 patients with PD in order to study its internal consistency, test-retest reliability, construct, and discriminant validity. Results The internal consistency of GDS was excellent (α = 0.903), as well as the test-retest reliability (ICC = 0.941 [95% CI: 0.886–0.970]). GDS showed a strong correlation with instruments related to the depression (ρ = 0.880) in PD (ρ = 0.712) and a weak correlation with generic measurement instruments (−0.320 < ρ <−0.217). An area under the curve of 0.892 (95% CI 0.809–0.975) indicated a moderate capability to discriminate depressed patients to nondepressed patient, with a cutoff value between 15 and 16 points that predicts depression (sensitivity = 87%; specificity = 82%). Conclusion The GDS is a reliable and valid tool in a sample of Italian PD subjects; this scale can be used in clinical and research contexts.
Highlights
Parkinson disease (PD) is characterized by motor and nonmotor symptoms
A recent systematic review about depression tools in PD patients recommended the use of the Hamilton Depression Inventory as a rating scale, which takes into consideration the judgment of the clinician or the caregiver, and the Geriatric Depression Scale (GDS), that considers the patient’s point of view, for the screening and measurement of the degree of perceived depression in patients with PD [5]
Each item is rated by a dichotomous score, and some items (Item numbers 1, 5, 7, 9, 15, 19, 21, 27, 29, and 30) presented a reverse score. e total score is given adding the item scores, and it ranged from 0 to 30 points. e Italian version used in this study demonstrated to be reliable and valid [25]
Summary
Parkinson disease (PD) is characterized by motor and nonmotor symptoms. Nonmotor symptoms include gastrointestinal dysfunctions, sleep disorders, cognitive disorders, and neuropsychiatric disturbances. Depression has been found to be more frequent in PD patients than in age-matched healthy controls or in patients with other chronic medical conditions [2, 3]. To measure the level of depression, it is crucial that clinicians and researchers have access to reliable and valid instruments. A recent systematic review about depression tools in PD patients recommended the use of the Hamilton Depression Inventory as a rating scale, which takes into consideration the judgment of the clinician or the caregiver, and the Geriatric Depression Scale (GDS), that considers the patient’s point of view, for the screening and measurement of the degree of perceived depression in patients with PD [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
