The dexamethasone suppression test and the diagnosis of depression in adults with severe and profound developmental disabilities.

Researchers gave the dexamethasone suppression test (DST) to adults with severe or profound intellectual disability. They wanted to see if the blood test could spot depression in this group. The study was a small case series run in 1995.

The test failed. It found depression in only 22 % of the adults who were actually depressed. Doctors could be less than 35 % sure any result was right. The DST was wrong more often than it was right.

Later work shows better tools exist. McLennan et al. (2008) adapted the Hospital Anxiety and Depression Scale for adults with ID and got good reliability. Madden et al. (2003) built the ADAMS scale just for people with ID and also found strong psychometrics. These studies extend the 1995 paper by giving you workable screens after the DST flopped.

Vargas-Vargas et al. (2015) and Putnam et al. (2003) ran similar small psychometric studies. Both found their tools had limits, backing up the idea that mainstream tests often miss the mark in severe ID. The field has moved from blood tests to caregiver interviews and adapted questionnaires.

If you assess mood in adults with severe or profound ID, skip the DST. Use the ADAMS or the adapted HADS instead. They give you scores you can trust and save you from false negatives. Start with a caregiver interview and add one of these validated scales when you need a written baseline.