What is the clinical effectiveness of e-therapy interventions for the treatment of anxiety?
In this review, ten studies were evaluated of which three were systematic reviews/meta-analyses of randomized controlled trials (RCTs) and seven were individual RCTs not included in the three systematic reviews. All studies included therapist-guided e-therapy interventions for generalized anxiety disorder, panic disorder, or social anxiety disorder. The studies were heterogeneous with respect to the specific intervention implemented, the type of therapist-guidance provided, the qualifications and expertise level of therapists, and measurement tools used to assess outcomes. Participants self-selected into studies and may have represented people with anxiety disorders who were more motivated. Two meta-analyses and one RCT focused specifically on generalized anxiety disorder. In all three studies, statistically significant effects were observed in favour of therapist-guided e-therapy interventions compared with waitlist, care as usual, information, or other psychological placebos, on several validated instruments. Two meta-analyses and two RCTs included participants with panic disorder. Therapist-guided e-therapy interventions were superior to the same controls, across several measurement instruments in all but one study that had 39 participants with panic disorder. Three meta-analyses and three RCTs examined the effect of e-therapy interventions in people with social anxiety disorder. All studies demonstrated benefits of interventions compared with passive or active controls. One study examined individual and group therapist-guided e-therapy for social anxiety disorder and found that both were superior to waitlist. One meta-analysis and two RCTs (in older adults 60 years of age or over) with mixed anxiety disorders were identified. All three studies found benefits of therapist-guided e-therapy interventions compared with waitlist or general weekly email support. No data were available for generalized anxiety disorder, panic disorder, or social anxiety disorder for the following subgroups of interest: military, para-military, and veteran populations. Most studies found that treatment responses were maintained at follow-ups of three to 24 months, although this data must be interpreted with caution as controls were not available and participants may have started other treatments during the follow-up period.Three studies reported large number of losses to follow-up, of 25% to 33%. Losses were similar among intervention and control groups in most studies. In one study of older adults, a larger percentage in the e-therapy intervention group was lost to follow-up compared with general weekly email support (33% vs. 3%).The evidence base suggested that therapist-supported e-therapy interventions are effective for generalized anxiety disorder, panic disorder, and social anxiety disorder compared with waitlist and active controls, but may have similar effects as face-to-face CBT.