What the evidence says, including its weakness
Two things worth holding at once. The evidence for this treatment is genuinely strong, and it is also honest about its own limits, which we would rather show you than tidy away. The report is the one people forget: seeking a remedy sits inside the tradition, not outside it.
Qur’an and Sunnah
Jabir reported Allah's Messenger (ﷺ) as saying:There is a remedy for every malady, and when the remedy is applied to the disease it is cured with the permission of Allah, the Exalted and Glorious
Sahih Muslim 2204graded sound, sahihaynfull report
What the research says
Reid JE, Laws KR, Drummond L, Vismara M, Grancini B, Mpavaenda D, Fineberg NA (2021). Cognitive behavioural therapy with exposure and response prevention in the treatment of obsessive-compulsive disorder: a systematic review and meta-analysis of randomised controlled trials. Comprehensive Psychiatry, 106, 152223 doi
36 randomised trials, 2,020 people. CBT with exposure and response prevention beat waiting lists and control conditions by a large margin, Hedges g 0.74. The same authors report that trials run by researchers with an apparent allegiance to the treatment found far larger effects than trials without, which is a real weakness in the evidence base and is stated here rather than smoothed over.