Introduction Adolescent depression poses a major public health concern with substantial clinical and societal implications. Both internet-delivered cognitive behavioural therapy (ICBT) and internet-delivered psychodynamic therapy (IPDT) have shown efficacy, but questions remain regarding long-term efficacy and cost-effectiveness. The present study presents a 12-month follow-up and cost-comparison from a randomized controlled trial (RCT) comparing ICBT and IPDT for adolescent depression. Methods Participants were 272 adolescents aged 15–19 with a primary diagnosis of major depressive disorder. The primary outcome was depressive symptoms measured with the QIDS-A17-SR while the secondary outcome was anxiety symptoms measured with the GAD-7. Costs were assessed both by comparing costs of treatment and healthcare use 12-month post-treatment using the TIC-P. Results Results were stable at the 12-month follow up compared to treatment endpoint, for both depressive and anxiety symptoms. There were no significant group differences at the 12-month follow-up. There were no differences in treatment costs or in costs for healthcare use one-year post-treatment. Discussion This study suggests that treatment gains from IPDT and ICBT for adolescent depression remain stable during a 12-month follow-up period, with no differences between the treatments one-year post-treatment. Furthermore, it suggests comparable costs for the treatments. Interpretation of health-care use data was restricted due to the COVID-19 pandemic taking place during the follow-up period. This adds to the literature suggesting that ICBT and IPDT can be seen as viable alternatives for treating adolescent depression. More research into the long-term effects and cost-effectiveness is needed.
Lindqvist et al. (Mon,) studied this question.