Illness duration and treatment outcome of intensive cognitive-behavioral therapy in adolescents with anorexia nervosa.

ABSTRACT

OBJECTIVE: This study aimed to compare the effectiveness of an intensive treatment based on enhanced cognitive-behavioral therapy (CBT-E) in patients aged between 12 and 18 years with anorexia nervosa with a duration of illness <3 versus ≥3 years. METHODS: One hundred and fifty-nine consecutively treated patients (n = 122 with illness duration <3 years and n = 37 ≥ 3 years) were enrolled in a 20-week intensive CBT-E program. All patients underwent assessment at admission, end of treatment (EOT), and 20-week follow-up. The following measures were used body mass index (BMI)-for-age percentile and percentage of expected body weight (EBW), Eating Disorder Examination Questionnaire, Brief Symptom Inventory, and Clinical Impairment Assessment. RESULTS: Approximately 81% of eligible patients began the program, with over 80% successfully completing it. Patients with a longer or shorter duration of illness did not show significantly different treatment outcomes. In detail, BMI-for-age percentile and percentage of EBW outcomes were significantly improved from baseline to EOT, remaining stable until 20-week follow-up in both groups. Similarly, in both groups, scores for eating disorder psychopathology, general psychopathology, and clinical impairment decreased significantly at EOT and remained stable from EOT to follow-up. Furthermore, a substantial percentage of adolescents in both groups achieved a good BMI outcome at EOT and 20-week follow-up, with approximately 60% maintaining a full response at the latter time point. DISCUSSION: These findings suggest that intensive CBT-E appears to be an effective treatment for severely ill adolescent patients with anorexia nervosa, regardless of whether the duration of illness is shorter or longer than 3 years. PUBLIC SIGNIFICANCE: Existing treatment outcome studies in adolescents, whether randomized controlled trials or longitudinal investigations, typically involve patients with less than 3 years of illness, while data on the treatment outcomes for adolescents with anorexia nervosa with an illness duration of 3 years or over is very limited. Our findings suggest that adolescents with anorexia nervosa, irrespective of the duration of their illness, can derive similar benefits from intensively CBT-E.