Levels of evidence supporting American, European and international guidelines in psychiatry, 2014-2024: a systematic...

To what extent are psychiatry guidelines supported by high-level evidence?

Guidelines from the American Psychiatric Association, European Psychiatric Association, WHO and World Federation of Societies for Biological Psychiatry (2014-2024) were selected. Recommendations were graded by guideline authors' levels of evidence (LOE) appraisal (standardised to the Grading of Recommendations, Assessment, Development and Evaluations framework (high, moderate, low, very low)) and by the highest-level study referenced (meta-analysis, randomised controlled trial (RCT), observational study, expert opinion, etc.).

24 guidelines, containing 545 recommendations, were included. Of 82 guidelines screened, 29 (35%) had not been updated in a decade. 63 (11.6%) recommendations were rated by guideline authors as based on high LOE. The proportion was the highest for pharmacotherapies (41/281 (14.6%)) and the lowest for somatic assessment (0/13 (0%)). The proportion of high LOE recommendations varied between publishers (European Psychiatric Association: 20 %, WHO: 1.6 %). For high LOE recommendations, only those concerning pharmacotherapies cited meta-analyses based on double-blind studies using adequate controls. A large proportion (n=241 (44.2%)) of recommendations cited either a meta-analysis of RCTs (n=155 (28.4%)) or ≥two RCTs (n=86 (15.8 %)). There were few recommendations primarily addressing self-harm (n=2), autism (n=3), attention-deficit/hyperactivity disorder (n=3), prevention (n=3), patient involvement (n=3) or discontinuation (n=6).

Clinical guidelines in psychiatry frequently cite RCTs, but the evidence is often downgraded by guideline authors, highlighting the need for better quality trials. LOE varies across areas, with pharmacotherapies supported by the highest quality evidence. Organisations should commit to a timely update of guidelines covering all areas of psychiatry.