The prevalence of ASD among the adult population is estimated to be 1 percent. Despite high rates of anxiety and depression among adults with ASD, treatment methods for these comorbid conditions have not been systematically studies or compared in this patient population. Recently, MBSR and CBT protocols were adapted for adults with ASD and could be excellent candidate therapies for reducing anxiety and depression.

We wanted to study the ability of both treatment methods to reduce anxiety and depression symptoms among adults with ASD, and to determine which therapy is best suited for which patient.

A three-arm RCT among 90 adults with ASD (30 MBSR, 30 CBT, and 30 treatment as usual, (TAU)), was conducted in an outpatient setting with measurements at the start and end of the 14 week treatment period, and at 3 months follow-up. Prior informed consent and medical ethical approval was obtained. Instruments included the hospital anxiety and depressions scale, rumination, irrational belief and mindfulness scales, and an autism symptom checklist.

Preliminary results indicate that both MBSR and CBT lead to a significant reduction in anxiety and depression among adults with ASD. Both MBSR and CBT were superior to TAU. There was no gender or age effect. Effectiveness in relation to patient characteristics will be discussed.

Mindfulness and cognitive behavioral therapies are promising treatment methods to reduce comorbid anxiety and depression in adults with ASD.