Internet-delivered cognitive behavioural therapy for post-traumatic stress disorder : systematic review and meta-analysis

Objective: To determine whether Internet-delivered cognitive behavioural therapy (i-CBT) is an effective treatment for those who meet diagnostic criteria for post-traumatic stress disorder (PTSD). 
Method: A systematic review was undertaken according to Cochrane Collaboration Guidelines. The primary outcome measures were reduction in PTSD symptoms and drop-out. Categorical outcomes were meta-analysed as risk ratios (RRs) and continuous outcomes as mean differences (MDs) or standardised mean differences (SMDs).
Results: Ten studies with 720 participants were included. Evidence showed that i-CBT may be associated with a clinically important reduction in post-treatment PTSD symptoms compared with wait list (SMD - 0.60, 95% confidence interval   - 0.97 to - 0.24; N = 560); however, only three studies reported follow-up data, and there was no evidence to support the maintenance of symptom improvement at follow-up of 3–6 months. There was no evidence of a difference in PTSD symptoms between i-CBT and Internet-delivered non-CBT posttreatment.
There was evidence of greater treatment effect from traumafocused i-CBT than i-CBT without a trauma focus, as well as evidence that treatment effect was increased by the provision of guidance. 
Conclusions: While the review found some beneficial effects of i-CBT for PTSD post-treatment, the quality of the evidence was very low because of the small number of included trials and there was insufficient evidence to support the maintenance of improvement at follow-up of 3–6 months. Further work is required to establish non-inferiority to current first-line interventions; to determine long-term efficacy; to explore mechanisms of effect; and to establish optimal levels of guidance.