Digitally Delivered Psychological Interventions for Anxiety Disorders: a Comprehensive Review.

Digital interventions for anxiety disorders have been well-researched over the past two decades. However, reviews to date have focused on internet-based cognitive behavioural therapy (iCBT), whereas other psychological interventions have received less attention. The aim of this review was therefore to evaluate the effectiveness of digitally delivered psychological therapies (CBT, Attention Bias Modification, Exposure Therapy, Applied Relaxation, Bibliotherapy, Psychodynamic Therapy, Mindfulness, Behavioural Stress Management, Counselling) compared with control conditions and/or other psychological interventions for anxiety disorders (Social Anxiety Disorder (SAD), Health Anxiety, Obsessive-Compulsive Disorder (OCD), Post-traumatic Stress Disorder (PTSD), Specific Phobias, Panic Disorder (PD), Generalised Anxiety Disorder (GAD)]. 68 randomised controlled trials (RCTs) were reviewed. SAD was the anxiety disorder for which the most RCTs were conducted. Overall, findings support the effectiveness of iCBT for SAD; for the remaining interventions, although some RCTs indicated significant improvement (within groups) at post-treatment and/or follow up, between group findings were less consistent and overall, methodological differences across trials failed to provide strong supporting evidence. Finally, the level of therapist contact or expertise did not appear to affect much treatment effectiveness. Additional large, methodologically rigorous trials are needed to investigate further whether different digitally delivered psychological interventions are equally effective for anxiety disorders. Moreover, further studies are pertinent in order to examine the maintenance of therapy gains after the end of treatments and understand how these work [(e.g. the influence of therapist factors, user engagement and/or satisfaction, potential access barriers and treatments with diverse population groups (e.g. BME groups)].