Attachment and mentalization as predictors of outcome in family therapy for adolescent anorexia nervosa
Objective: Anorexia nervosa focussed family therapy (FT-AN) is the first-line treatment for adolescent anorexia nervosa (AN), but the predictors of poor treatment response are not well-understood. The main aim of this study was to investigate the role of attachment and mentalization in predicting treatment outcome at nine months. Therapeutic alliance at one month was tested as a potential mediator of the effect of attachment and mentalization at baseline on outcome at nine months.Method: 192 adolescents with AN and their parents were recruited as they began family therapy in out-patient specialist eating disorder services. Self-report measures of attachment, mentalization and emotion regulation were completed at the start of treatment by adolescent patients and one of their parents. Self-reported alliance scores were collected at one month. Results: Higher scores on the Certainty Scale of the Reflective Functioning Questionnaire, completed by parents, which indicate over-certainty about mental states, were the strongest predictor of poor outcome (Odds Ratio: .42, CI: .20 to .87). Similarly, for adolescents, higher Lack of Clarity scores on the Difficulties in Emotion Regulation Scale, representing being unclear about one’s feelings, were predictive of positive treatment outcome (OR: 1.10, CI: 1.00 - 1.21). Alliance scores at one month were predictive of success but did not play a mediating role in relation to baseline predictors.Conclusion: These novel findings suggest that, particularly in parents, a tendency towards inappropriate certainty about mental states in others may predict poor outcome in family therapy for adolescent AN. Further research is warranted to replicate the finding and characterise families at risk of poor outcome.