An internet-based treatment supported by a therapist led to a greater reduction in depressive symptoms among adolescents with depression than standard care, at a lower treatment cost. This is shown in a new study from Karolinska Institutet published in the journal BMJ Mental Health. At the same time, the results suggest that a self-guided internet-based treatment may be a cost-effective alternative where access to therapists is limited, although the clinical effect is more uncertain.
Photo: Lenart Kriisa
Depression among young people is a growing public health issue, while many struggle to access psychological treatment. In the current study, researchers investigated whether internet-delivered behavioural activation, a treatment aimed at reducing depression by helping people resume meaningful daily activities, could be an option for adolescents with mild to moderate depression.
Internet-based treatment compared with usual care
The study included 219 adolescents aged 13 to 17 from across Sweden. Participants were randomly assigned to three groups: internet-based treatment with therapist support, internet-based treatment without therapist support, or usual care within child and adolescent mental health services or primary care services for children and young people with mild to moderate psychiatric difficulties. The treatments lasted ten weeks and included digital modules for both adolescents and their guardians. In the therapist-supported version, the adolescents received feedback and support from a therapist during the treatment.
Therapist support produced the clearest results
At the three-month follow-up after treatment had ended, symptoms of depression had decreased in all groups. Adolescents who received internet-based treatment with therapist support improved more than those who received usual care. The self-guided treatment also showed a greater reduction in symptoms than usual care, but the difference was not statistically significant. Symptoms of depression were assessed by clinicians who did not know which treatment the adolescents had received.
Both internet-based treatments were less costly than usual care, and the self-guided treatment was the most cost-effective option.
“Many young people with depression have to wait a long time for treatment. Our results suggest that internet-based treatment with therapist support could be a cost-effective alternative and may help increase access to treatment,” says Rebecca Andersson, postdoctoral researcher at the Centre for Psychiatry Research at the Department of Clinical Neuroscience , Karolinska Institutet, and first author of the study.
At the same time, the researchers stress that the results are not entirely clear-cut. Outcomes varied depending on the analytical method used. In the predefined primary analysis, young people who received therapist-supported internet-based treatment improved more than those who received standard care, but in an alternative statistical model the difference was no longer statistically significant. Other analyses suggested that both forms of internet-based treatment were more effective than standard care.
“Self-guided treatment may be an option where access to therapists is limited, but more research is needed to better understand which young people the format works well and safely for,” says Rebecca Andersson.
According to the researchers, the study is the first larger randomised trial of behavioural activation for adolescent depression to also include a health economic evaluation. The long-term follow-up will be reported in a forthcoming publication.
Funding and conflicts of interest
The study was funded by Kavli Trust, Frimurare Barnhusdirektionen in Stockholm and Lund, Child and Adolescent Psychiatry Services in Region Stockholm and Region Skåne, ALF Region Stockholm, the Swedish Research Council, the Jane and Dan Olsson Foundation, the King Oscar II and Queen Sophia Golden Wedding Memorial Foundation, and the Thuring Foundation. Karolinska Institutet funded the open access publication. The funders had no role in the design of the study, data collection, analysis or interpretation of the results, or in the preparation of the publication.
David Mataix-Cols and Eva Serlachius are part-owners of Scandinavian E-Health AB, which was not involved in the study’s funding, design, interpretation, or manuscript preparation. David Mataix-Cols receives compensation for articles in UpToDate and editorial work for the Spanish Journal of Psychiatry and Mental Health. Fabian Lenhard is a scientific adviser to Eatit AB and a board member of Psychologists for Sustainable Development. The authors declare no other relationships or activities that influenced the work.
Publication
Andersson R, Ahlen J, Lenhard F, Ohlis A, Wachtmeister V, Karemyr M, Högstrom J, Bottai M, Mataix-Cols D, Vigerland S, Serlachius E. ‘Therapist-guided and self-guided internet-based behavioural activation versus treatment as usual for adolescents with depression: randomised controlled trial with economic evaluation’. BMJ Mental Health. 2026;29:1-10. doi:10.1136/bmjment-2026-302619 .
