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 post‐treatment. There was evidence of greater treatment effect from trauma‐focused 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.