Translation and Psychometric Evaluation of the Swedish Glasgow Depression Scale for People With a Learning Disability (GDS-LD)

Depression is difficult to identify in individuals with intellectual disability (ID), partly due to the limited availability of screening tools adapted for this population. This study aimed to translate the Glasgow Depression Scale for People with a Learning Disability (GDS-LD) into Swedish and to provide initial evidence regarding its psychometric properties.

The translation followed established forward-backward procedures, supplemented by expert review and user testing. Content validity was assessed through item review with four adults with ID. The Swedish GDS-LD was administered to 26 adults with mild ID, including participants with and without clinically assessed depressive symptoms. Test-retest data were collected from 22 participants.

The Swedish GDS-LD demonstrated good internal consistency (α = 0.90) and high test-retest reliability (r = 0.93). All but two items showed acceptable item-total correlations (> 0.30). Participants with a higher clinically assessed likelihood of depression scored significantly higher on the GDS-LD than comparison participants, supporting its ability to distinguish between groups. Exploratory analyses further suggested that the use of a total score may be appropriate.

The Swedish GDS-LD demonstrated promising preliminary psychometric properties in this pilot sample of adults with mild intellectual disability. The findings support further evaluation in larger and more heterogeneous samples before conclusions can be drawn regarding its broader psychometric performance and clinical application.