Symptom trajectories throughout two family therapy treatments for adolescent anorexia nervosa

This study aimed to examine the trajectory of symptom remission and affective functioning throughout the course of two family-based treatments for adolescent anorexia nervosa (AN): conjoint family-based treatment (FBT) and parent-focused treatment (PFT).

Participants were 107 adolescents (M_age  = 15.5 years, SD = 1.5) with a primary diagnosis of AN who participated in a randomized clinical trial comparing FBT (N = 55) and PFT (N = 51). Patient weight and self-reported assessments of dietary restraint and positive and negative affect were recorded at regular intervals throughout treatment.

Multilevel models revealed increases in weight (β = 0.33, p < .001) and positive affect (β = 0.03, p < .001), and decreases in dietary restraint (β = -0.03, p < .001) and negative affect (β = -0.04, p < .001) over the course of treatment. No significant effects emerged by treatment type.

These findings suggest that PFT may bring about comparable trajectories of weight gain and reduced dietary restraint as conjoint FBT, despite adolescents not being directly involved in treatment. These findings also highlight that the exclusively behavioral focus throughout both PFT and FBT is associated with significant increments in positive affect and significant reductions in negative affect.