Diagnosing depression in patients with dementia has long been a clinical challenge, with overlapping symptoms frequently complicating the process. Now, researchers from Mater Research and The University of Queensland have developed a highly accurate screening tool specifically optimised for this population.
The Geriatric Depression Scale (GDS) is a standard 30-question test widely used to screen for depression. However, for patients living with dementia, it can be misleading. Questions about memory loss, apathy, and hopelessness overlap with standard dementia symptoms. Because of this overlap, the standard test can easily lead to a false-positive depression diagnosis.
To address this, the research team created the GDS-D (Geriatric Depression Scale, Dementia version), a refined 10-item questionnaire which removed items from the standard test that are likely to be confounded by neurodegenerative disease processes.
Lead researcher Dr Joshua Flavell said the team found that existing shorter versions of the GDS still included questions that could confound the diagnosis of depression in a patient with dementia.
"To address these limitations, our goal was to develop a modified version that minimised confounds by focusing particularly on items probing depressed mood and anhedonia," said Dr Flavell
The retrospective study analysed data from 82 patients assessed at the Mater Memory and Cognitive Disorders Clinic and The University of Queensland. The results demonstrated that the new GDS-D achieved an accuracy of up to 92 per cent in diagnosing depression in some cohorts.
This performance was superior to the original 30-item test and all other abbreviated versions.
Senior author Professor Peter Nestor highlighted the clinical utility of the new scale.
"The exclusion of cognitive, apathy-related and other potentially confounding items enhanced the diagnostic accuracy of the GDS-D relative to other abbreviated versions," Prof Nestor said.
"It performs better at diagnosing depression in a dementia cohort, making it a superior tool for memory clinics."
The researchers noted that while these initial findings strongly support the GDS-D as a promising clinical screening tool, future prospective studies should validate its utility in larger, diverse dementia populations.
