An open trial of the feasibility of brief internet-delivered acceptance and aommitment therapy (iACT) for chronic anxiety and depression.

Anxiety and depressive disorders are common, often chronic and result in significant disability and distress. The delivery of psychological interventions via the internet is now recognised to be a safe and effective way to treat these disorders. The predominant therapeutic model in clinical trials and in routine care has been cognitive-behavioural therapy (CBT), which helps patients identify and modify unhelpful thoughts and behaviours. However, other models of treatment for anxiety and depression, such as acceptance and commitment therapy (ACT), which uses the examination of both positive and negative experiences in the service of living a personally meaningful and values-based life, have been developed and tested, although most of these interventions are long and require more clinician support to ensure adherence and achieve positive outcomes. The aim of the present study was to examine the feasibility of a new brief, clinician supported transdiagnostic internet-delivered (iACT) program, designed to treat symptoms of both anxiety and depression and improve social function. A single-group open trial was conducted on 24 adults with long-term symptoms of anxiety and depression. The course is comprised of five online modules delivered over 8 weeks either self-guided or with support from a clinician. There was a high course completion rate (70 %) and a high level of satisfaction with the course (94 % satisfied or very satisfied). Significant clinical improvement in our primary outcome measures (within-group Cohen's ) of anxiety ( ≥ 0.62), depression ( ≥ 0.63), disability ( ≥ 0.43) and quality of life ( ≥ -0.57) were observed at posttreatment. Relatively little clinician time was required per participant (M = 30.6 min,  = 5.7). The findings of the current study support the feasibility and potential of a transdiagnostic iACT treatment for adults experiencing long-term symptoms of anxiety and depression, including those patients who have not derived benefit from other treatments.