A preliminary investigation of a Geriatric Depression Scale, Dementia version (GDS-D).

BACKGROUND

Depression is a frequent comorbidity in dementia; however, diagnosis is complicated by overlapping cognitive and behavioural symptoms. The Geriatric Depression Scale (GDS) is a widely used screening tool to probe for depression, comprising 30 items in its full version (GDS-30) but also existing as a range of shorter versions (GDS-15, GDS-10, GDS-8, GDS-4). All versions contain items that may be confounded in dementia patients such as probes for cognitive symptoms, apathy, and negative feelings about the future. This study aimed to develop and validate a 10-item version (GDSD) optimised for diagnosing depression in dementia by removing these confounds.

METHODS

Data were retrospectively analysed in participants with Alzheimer's disease (AD, n = 29), frontotemporal dementia (FTLD, n = 30), or a depressive disorder (n = 23) who had completed the GDS-30 and undergone psychiatric assessment and application of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria. Diagnostic accuracy of the GDS-D was compared to all previous GDS versions using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

The GDS-D had an accuracy of 92-97 % in diagnosing depression in a memory clinic setting and in dementia (AD and FTLD), which was superior to the GDS-30 and all briefer versions.

CONCLUSION

The GDS-D enhances depression screening in a memory clinic setting by excluding the confounding items of other GDS versions. In addition, it performs better at diagnosing depression in a dementia cohort. Future studies should validate its utility in larger, diverse dementia populations.