Effects of family-based treatment on adolescent outpatients treated for anorexia nervosa in the Eating Disorder Unit of Helsinki University Hospital

Background: Family therapy for adolescent anorexia nervosa (AN) has stronger evidence of efficacy in comparison with individual therapy, and family-based treatment (FBT) is the most evaluated in numerous randomized clinical trials. However, few studies have focused on how FBT performs outside of research settings. The current study is the first to assess clinical outcomes of FBT for adolescent AN in Finland, in a specialized outpatient clinic. Aim: The naturalistic outcome of outpatient FBT for adolescent AN was investigated. Methods: Fifty-two female patients and their families who received FBT at a tertiary eating disorders unit participated in the study. Data on their pre-treatment parameters, treatment details, and condition at the end of treatment (EOT) was collected from their medical records. Results: At EOT, a majority (61.5%) had achieved a full weight restoration [percentage of expected body weight (%EBW) ≥ 95%]. Participants with an %EBW ≥ 95 at EOT had a significantly higher pre-treatment %EBW than those with an EBW < 95% at EOT. Participants with an EBW ≥ 95% at EOT showed significantly higher total weight gain during the treatment period, a higher rate of regular menstrual periods at EOT, significantly lower rates of dietary restrictions, and less cognitive or behavioral symptoms of the eating disorder overall, compared to participants who did not achieve a normal body weight. In 22 cases (42.3%), there was no need for further treatment at the end of FBT. Participants who needed further treatment after FBT, compared to those who did not, showed significantly higher rates of psychiatric comorbidity, history of mental health treatment, and need for psychopharmacological treatment. Conclusions: In this naturalistic study, and in line with previous studies, FBT for AN appeared to be an effective and sometimes sufficient intervention, especially for patients with milder weight deficit and less severe psychiatric comorbidities. The results show that FBT can be successfully implemented in Finland and suggest that training more ED clinicians in FBT would be beneficial. Trial registration: The study was retrospectively registered on February 8th, 2023, in ClinicalTrials.gov Protocol Registration and Results System, identifier: NCT05734573.