What do we know today about the prospective long-term course of social anxiety disorder? A systematic literature review

•Social anxiety disorder (SAD) is common, while knowledge about its long-term course is sparse.•Naturalistic findings point towards a chronic course of SAD within clinical samples.•The course seems to be more favorable in population based and primary care samples.•Pre-to follow-up effect sizes on self-report scales after psychotherapy are mostly large.•Observer-rated remission rates after psychotherapy range between 36% and 100%.

While we know that social anxiety disorder (SAD) is today's most common anxiety disorder knowledge on its prospective long-term course is sparse. We conducted a systematic literature search using databases Medline and PsycINFO for naturalistic and psychotherapy outcome studies with follow-up durations of at least 24 months. Four naturalistic cohorts and nine psychotherapy trials were included in the review. The naturalistic course in clinical was less favorable than in non-clinical samples (27% vs. 40% recovery rate after 5 years). Psychotherapy trials, all applying (cognitive) behavioral methods, yielded stable outcomes with overall large pre- to follow-up effect sizes on self-report scales. Observer rated remission rates varied considerably (36% to 100%) depending on study design and follow-up length. The results of psychotherapy trials and that of naturalistic studies can hardly be compared due to differences in methodology. More standardized remission and recovery criteria are needed to enhance the understanding of the longitudinal course.