Study of Web-based Cognitive Behavioral Therapy in Adolescent Depression; Randomized Controlled Trial for Korean Adolescents

We will recruit adolescents(age 12-18 years old) with a diagnosis of major depressive disorder, dysthymia and depressive disorder NOS in outpatient clinic of child and adolescent psychiatry and we will advertise for recruitment of subjects in community. The study protocol will be approved by the Institutional Review Board of the Hallym university sacred heart hospital. Well- trained interviewers will conduct the assessments of participants and their parents or guardians. The assessment included the diagnostic interview, demographic characteristics, depressive symptom severity scale , Columbia suicide severity rating scale, questionnaire about abuse histories.

We decided the number of participants of 164, because in previous studies, web- based cognitive behavioral therapy showed mild to moderate effect size (effect size = 0.43). So for examining the hypothesis, we will recruit 164 adolescents by calculating the number of participants using G power program version 3.1.3. (level of significance = 5%, power of a hypothesis test = 80%, drop out rate = 20%)

And we will conduct randomized controlled trial for examining the efficacy of web- based cognitive behavioral therapy. Our hypothesis is web- based cognitive behavioral is more effective than supportive psychotherapy, so we will deliver web- based cognitive behavioral therapy program to cognitive behavioral therapy group for 8 weeks(once in a week), and supportive psychotherapy to supportive psychotherapy group for 8 weeks(once in a week) We will exclude the participant if the participant has severe depressive symptoms, definite suicidal idea, plan and attempt, psychotic symptoms, bipolar disorders, sexual abuse histories, other neurological diseases or received cognitive behavioral therapy, pharmacotherapy or interpersonal psychotherapy.

We will analyze the intent- to- treat population. For each individual, missing values are replaced by the last observed value of that variable. And we will use Chi square test or repeated measure-ANOVA.