Patients who have done a course of CBT to treat their anxiety still show improvements a year later, a meta-analysis shows.

Furthermore, people with PTSD, generalised anxiety disorder and social anxiety disorder appear to continue to benefit after the 12-month mark, but data with such long-term follow-up are scarce, the investigators say.

Dutch researchers examined 69 randomised controlled trials of CBT with at least one month of follow-up, involving a total of more than 4100 participants with a range of anxiety disorders, including panic disorder, specific phobias and obsessive-compulsive disorder (OCD).

For generalised anxiety disorder, panic disorder and social anxiety disorder, effect sizes for CBT compared with various controls were small-to-medium at 6-12-month follow-up. A larger effect size (medium) was seen for PTSD.