Background. No consistent first-option psychological interventions for adult outpatients with anorexia nervosa (AN) emerges from guidelines. A random-effect network meta-analysis (NMA) of randomised controlled trials (RCTs) about stand-alone non-pharmacological treatments was conducted. The aim of the present work is to compare stand-alone psychological interventions for adult outpatients with AN with a specific focus on weight, eating disorder symptoms and all-cause dropout rate. Methods. We searched CENTRAL, CINAHL, MEDLINE, and PSYCINFO for published and unpublished literature until March 20th, 2020. We included RCT for the treatment of adult outpatients with acute AN, defined according to standardised criteria and assessing a stand-alone treatment. Primary outcomes were change in body mass index (BMI), change in clinical symptoms and all-cause dropout rate. Global and local inconsistencies for the NMA were measured, and CINeMA was used to assess the confidence in evidence for primary outcomes. Findings. Overall, 16 RCTs were included in the systematic review and 13 contributed to the NMA (overall, 1047 patients, 97.4% female). Seven interventions were assessed: treatment as usual (TAU), cognitive behavioural therapy (CBT), Maudsley Anorexia Nervosa Treatment for Adults, family therapy, psychodynamic psychotherapies, and two novel forms of CBT (targeting compulsive exercise, adding cognitive remediation therapy). No intervention outperformed TAU in our primary outcomes, but all￾cause dropout rate was lower for CBT than psychodynamic psychotherapies (OR 0.54, 95% CI 0.31- 0.93). Heterogeneity or inconsistency emerged only for a few comparisons. Confidence in evidence was low to very low. Interpretation. When compared with TAU, specific psychological treatments for adult outpatients with AN can be associated with modest improvements in terms of clinical course and quality of life, but no reliable evidence supports the clear superiority or inferiority of the specific treatments for AN recommended by clinical guidelines internationally. Results from our analysis are based on the best data from existing clinical studies, but these findings should not be seen as definitive or universally applicable. There is urgent need to fund new research to develop and improve therapies for adults with AN. In the meanwhile, to better understand effects of available treatments, participant-level data should be made 3 freely accessible to researchers to eventually identify if specific subgroups of patients are more likely to respond to specific treatments. Funding. Flinders University Faculty Research Grant 2017/2018; NIHR Oxford Health Biomedical Research Centre (grant BRC-1215-20005)