The influence of therapy quality on outcomes from behavioural activation and guided self‐help treatments for depression in adults with intellectual disabilities

TL;DR

This study shows how the quality of therapy affects outcomes for depression treatments in adults with intellectual disabilities.

Contribution

It reveals that therapy quality interacts differently with treatment types, impacting outcomes in unexpected ways.

Findings

Lower quality therapy improved outcomes for guided self-help but worsened them for behavioral activation.

High-quality therapy showed similar outcomes for both treatment types.

Factors indicating high-quality therapy in one treatment may hinder engagement in another.

Abstract

We report the effect of quality of therapy delivery on outcomes in a randomized, controlled trial of behavioural activation (BA) and guided self‐help (GSH) for depression in adults with intellectual disabilities.

A study specific measure of quality was used in a linear mixed effect model to determine the effects therapy and therapy quality on therapy outcome.

There was a significant interaction between quality and treatment type, with lower quality therapy associated with better outcome for GSH but poorer outcome for BA, with little difference in outcomes at higher levels of therapy quality.

Factors suggesting high quality in individualized BA may indicate problematic engagement for GSH. More research into processes in therapy for people with intellectual disabilities is required.