Transdiagnostic internet-delivered CBT and mindfulness-based treatment for depression and anxiety: A randomised...

To examine the efficacy of transdiagnostic internet-delivered cognitive behavioural therapy (iCBT), mindfulness-enhanced iCBT, and stand-alone online mindfulness training compared with a usual care control group (TAU) for clinical anxiety and depression.

Individuals (N = 158) with a DSM-5 diagnosis of a depressive and/or anxiety disorder were randomised to one of the three clinician-guided online interventions, or TAU over a 14-week intervention period. The primary outcomes were self-reported depression (PHQ-9) and anxiety (GAD-7) severity at post-treatment. Secondary outcomes included adherence rates, functional impairment (WHODAS-II), general distress (K-10), and diagnostic status at the 3-month follow-up (intervention groups).

All three programs achieved significant and large reductions in symptoms of depression (g = 0.89-1.53), anxiety (g = 1.04-1.40), and distress (g = 1.25-1.76); and medium to large reductions in functional impairment (g = 0.53-0.98) from baseline to post-treatment and 3-month follow-up. Intention-to-treat linear mixed models showed that all three online programs were superior to usual care at reducing symptoms of depression (g = 0.89-1.18) and anxiety (g = 1.00-1.23).

Transdiagnostic iCBT, mindfulness-enhanced iCBT and online mindfulness training are more efficacious for treating depression and anxiety disorders than usual care, and represent an accessible treatment option for these disorders.