Related Experiment Video
Updated: Jan 21, 2026

Stress-Enhanced Fear Learning, a Robust Rodent Model of Post-Traumatic Stress Disorder
Published on: October 13, 2018
Internet-delivered cognitive behavioural therapy for post-traumatic stress disorder: systematic review and
C Lewis1, N P Roberts1,2, N Simon1
1Division of Psychological Medicine and Clinical Neurosciences, Cardiff University School of Medicine, Cardiff, UK.
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.
Related Concept Videos
Post-traumatic Stress Disorder
Symptoms and Behavioral Manifestations
A spectrum of distressing symptoms characterizes PTSD. Recurrent flashbacks, where individuals involuntarily relive traumatic events,...
Cognitive Therapy
Beck's Cognitive Therapy
Arbitrary Inference
Arbitrary inference involves making conclusions without sufficient...
Review and Preview
Percentiles are a type of fractile that partition data into...
Review and Preview
Cognitive Dissonance

