Obsessive-compulsive disorder, or OCD, involves unwanted intrusive thoughts and repetitive actions people feel driven to carry out to ease anxiety. Cognitive behavioural therapy is the usual psychological treatment. A recent systematic review looked at whether CBT delivered over the internet works for adults with OCD, pooling results from 12 randomised controlled trials with 1416 participants.
The review separated two formats: internet CBT with regular support from a therapist, and internet CBT that people worked through on their own. Guided internet CBT reduced OCD symptoms after treatment compared with active comparison treatments. The benefit was no longer statistically significant at follow-up. Guided internet CBT worked about as well as face-to-face CBT for accompanying anxiety and depression. Improvements in quality of life were small and not statistically significant. When compared with waiting-list or no treatment, the combined internet programs showed large reductions in OCD symptoms. Guided and self-guided formats did not differ significantly on any measure.
For people waiting to see a clinician, or living far from one, these findings suggest structured online CBT can be a reasonable option, particularly with therapist support. If OCD is affecting your daily life, speak with your GP or a psychologist about what might suit you.
What the researchers did
The authors ran a systematic review and meta-analysis, which means they searched the published literature for all eligible trials, combined the results statistically, and estimated an overall effect. They included 12 randomised controlled trials, together contributing 15 comparison arms and 1416 adults diagnosed with OCD. Every included study tested internet-based cognitive behavioural therapy, shortened to ICBT. The analysis distinguished guided self-help ICBT, where a therapist provides regular contact and feedback, from unguided self-help ICBT, where the person completes the program alone. Outcomes were grouped into OCD symptom severity, accompanying anxiety and depression, and quality of life, each measured straight after treatment and again at follow-up. Results are reported as Hedges' g, a standardised measure of effect size where roughly 0.2 is small, 0.5 is moderate and 0.8 is large.
What they found
Against active control conditions, meaning another form of active treatment rather than a waiting list, guided ICBT produced a small-to-moderate reduction in OCD symptoms after treatment (g = 0.378 across 9 comparisons). That advantage was smaller and no longer statistically significant at follow-up (g = 0.153). Guided ICBT matched face-to-face CBT for reducing co-occurring anxiety and depression, both after treatment (g = 0.278) and at follow-up (g = 0.124). Quality of life did not improve to a statistically significant degree at either point.
Compared with inactive controls such as a waiting list, the combined guided and unguided programs showed a large effect on OCD symptoms (g = 0.754), a moderate effect on accompanying anxiety and depression (g = 0.547), and a small effect on quality of life (g = 0.227). Guided and unguided formats did not differ significantly on any outcome, after treatment or at follow-up. The size of a study's sample was a significant moderator of the results. A moderator is a factor that changes how large an effect turns out to be, so this means the benefit looked different in larger trials than in smaller ones.
Why it matters in practice
Access to specialist OCD treatment is uneven. People in rural areas, those on long waiting lists, and people who find it hard to attend a clinic in person often wait months for evidence-based care. These findings indicate that a structured online CBT program can reduce OCD symptoms, and can ease the anxiety and depression that frequently travel with it. The clearest benefits appeared when a therapist stayed involved, though the direct comparison between guided and unguided formats did not reach significance. For a GP deciding whether to refer, guided online CBT is a defensible starting point when in-person therapy is not readily available.
The limits
The gains against active treatments were modest, and they faded by follow-up, so online CBT is not a guaranteed substitute for in-person therapy. Quality of life barely shifted, which matters because symptom scores and daily wellbeing are not the same thing. Some comparisons rested on only a handful of trials, which makes those estimates less certain. The review also flagged sample size as influencing the results, a sign that smaller studies may have distorted the picture. This is evidence that online CBT deserves a place among the options, not proof that it should replace face-to-face care. Anyone considering it is well served by discussing the choice with a GP or psychologist who can weigh severity, past treatment and personal circumstances.