A Randomised Feasibility Trial of a Low Intensity Intervention for Depression in Adults with Autism: The Autism Depression Trial (ADEPT)
High rates of co-occurring depression have been reported in Autism. Clinical guidelines recommend ‘low intensity’ psychological treatment based on cognitive behaviour therapy (CBT) as an effective treatment for mild-moderate depression. If adapted, CBT has been found to be effective in treating anxiety problems in children and adults with Autism if adapted. There has been less research into the usefulness of CBT as a treatment for co-occurring depression in Autism; several studies of group CBT showing mixed findings and no randomised controlled trials of individual, low-intensity CBT. There is a need to consider the feasibility of low intensity CBT for depression adapted for adults with Autism before investigating the effectiveness and efficacy of the intervention.
As part of a commissioned call by the NIHR HTA, this was a feasibility study for a large-scale Randomised Controlled Trial (RCT) that would determine the clinical and cost-effectiveness of a low intensity intervention for co-occurring depression in adults with autism.
The feasibility study comprises a randomised controlled trial (RCT) and nested qualitative evaluation in preparation for a future definitive RCT. Participants are adults with Autism (n=70), aged 18 years or over with a PHQ-9 score ≥ 10, randomised to Guided Self-Help (GSH): a low intensity psychological intervention based on Behavioural Activation adapted for ASD or Treatment as Usual (TAU). Outcome measurement at 10, 16 and 24 weeks post randomisation is blind to group allocation for those measures that are not self-administered. Measures include standardised measures of depression symptoms, anxiety, social function, and service use. The analysis will aim to establish the rates of recruitment and retention for a larger scale RCT as well as the most appropriate measure of depression to serve as primary outcome.
At the time of writing, 70 eligible participants had been recruited and randomised; 35 were allocated to Treatment as Usual (TAU) and 35 to Guided Self-Help (GSH), across the two trial sites. The average PHQ-9 score at baseline was 16, indicating a severe level of depression. 23 of the 35 participants allocated to GSH had completed their treatment, which is 92% of those who had reached their ten week follow-up. At 10 week follow-up, 43 participants had completed outcome measures. At 16 week follow-up, 34 had completed outcome measures. At 24 week follow-up, 23 participants had completed measures. There had been four adverse events, none related to trial participation. One participant in the GSH arm had withdrawn, and seven in the TAU arm had withdrawn, with an additional TAU participant lost to follow-up.
There is a need for evidence based psychological interventions in people with autism and co-occurring depression. This feasibility study considers if it is possible to conduct an effectiveness study of a newly developed, low intensity intervention for depression based on the principles of CBT for autistic adults.