Geriatric Depression Scale (GDS-15)

The Geriatric Depression Scale, known by the acronym GDS, is a widely used screening tool specifically designed to assess the presence and severity of depressive symptoms in older adults. Developed by Yesavage and colleagues, its main advantage is its simple response format, which avoids the complexity of multi-level scales. Instead, the patient answers only "yes" or "no" to a series of questions about their mood and feelings over the past week. The scale was originally created with 30 items (GDS-30), but several shorter versions have been validated and are now more common in clinical practice, with the GDS-15 (15 items) being the most widely used. Ultra-short versions (GDS-5 or GDS-4) also exist for very rapid screening. The GDS-15, which takes about 5 to 7 minutes to administer, is self-completed by the patient or can be read aloud by a clinician, which is useful for patients with visual or mild cognitive limitations. Scoring is calculated by assigning one point for each answer suggestive of depression (some questions are reverse-scored, where "no" is worth one point and "yes" is zero). On the GDS-15, the total score ranges from 0 to 15. A score of 0 to 4 is generally considered normal; a score of 5 to 9 suggests mild to moderate depression; and a score of 10 or more is almost always indicative of significant depression, warranting a more in-depth diagnostic evaluation by a mental health professional.