Characteristics of depression as assessed by the Diagnostic Assessment for the Severely Handicapped-II (DASH-II).

Matson et al. (1999) tested if the DASH-II depression subscale could tell depression apart from autism in adults with severe or profound intellectual disability.

The team gave the scale to three groups: adults with diagnosed depression, adults with autism, and adults with no emotional disorder. All lived in institutional settings.

The depression group scored higher on the DASH-II depression items than both other groups. Key signs were withdrawn behavior, sleep problems, and appetite changes.

The scale picked up behavioral equivalents, not just classic mood symptoms. This matters because many of these adults cannot say 'I feel sad.'

Palka Bayard de Volo et al. (2021) later reviewed many studies and agreed: aggression, self-injury, and sleep changes can signal depression in severe ID. They warn to rule out pain and autism first, which lines up with L et al.'s method.

Hurley (2008) saw things differently. In a chart review of 300 adults, classic signs like crying and sad face distinguished depression better than challenging behavior. The papers seem to clash, but D studied mostly mild-to-moderate ID while L et al. focused on severe/profound. The target group changes what clues you trust.

Matson et al. (2008) extended the idea to older adults. They found both DSM symptoms and behavioral equivalents on the interRAI ID predicted a depression diagnosis, backing the use of mixed signs.

If you support adults with severe/profound ID, the DASH-II depression subscale gives you a quick, structured way to spot possible depression without waiting for self-report. Pair it with ruling out medical issues and autism overlap. When scores are high, refer for psychiatric review and track behavioral equivalents like social withdrawal or sudden sleep changes during your next observation session.