Long-term follow-up of cognitive behavior therapy for obsessive-compulsive disorder in adults and children: a systematic review and meta-analysis.

Cognitive behavior therapy (CBT) has strong research support for obsessive-compulsive disorder (OCD). However, less is known about long-term follow-up effects of CBT in OCD. A systematic review and meta-analysis was conducted of different types of CBT for OCD in adults and children/adolescents. Four databases were systematically searched for studies published until March 2025. The effectiveness of CBT, methodological quality, and moderators were examined at post and follow-up. Forty-seven studies were included, comprising 2,817 participants. Attrition was lower in child (6.5%) than in adult studies (14.2%). Very large within-group effect sizes (ES; Hedges's g) were obtained for OCD-severity at post-treatment (2.35), and follow-up (2.54), on average 2.5 years post-treatment. Adult studies maintained the ES from post to follow-up, whereas child studies showed a significant further improvement. Average response rates were 70% post-treatment and 69% at follow-up. Mean recovery rates were 48% post-treatment and 52% at follow-up. The degree of change in OCD severity during initial treatment was a strong moderator of the long-term follow-up ES. Exposure and response prevention, cognitive therapy, and the combination all yielded very large ESs with no significant difference between them. In conclusion, CBTs for OCD are effective and the effects are maintained at long-term follow-up.