An online therapy for teen depression beat usual care, and missed its own threshold for mattering

219 adolescents were randomised to therapist-guided or self-guided internet behavioural activation, or treatment as usual. The guided version won on statistics at p=0.048, then failed the six-point difference the trial had set in advance as clinically meaningful.

Behavioural activation is a good candidate for digital delivery: it is structured, it is largely about scheduling activity, and it does not depend on a long therapeutic relationship. Researchers led by Rebecca Andersson randomised 219 Swedish adolescents aged 13 to 17 with mild to moderate major depressive disorder, one to one to one, to ten weeks of therapist-guided internet behavioural activation, self-guided internet behavioural activation, or treatment as usual. Both digital arms included modules for parents. The primary outcome was depression severity on the Children's Depression Rating Scale-Revised, rated by blinded evaluators at three-month follow-up. Baseline scores averaged 57.1, well above the clinical threshold of 40. Retention was 82.6%. Mean reductions were 17.0 points for therapist-guided, 16.0 for self-guided, and 11.6 for treatment as usual, which brought both digital groups below the clinical cut-off. The therapist-guided arm beat usual care by an estimated 4.68 points, with a confidence interval running from 0.05 to 9.30 and a p value of 0.048. The self-guided arm was not statistically superior. Here is the part worth sitting with: the trial had set a six-point difference in advance as the smallest change that would count as clinically important, and the result did not reach it. The authors also report that significance disappeared under a different modelling choice, though the effect estimates were similar. Both digital options cost less than usual care, with self-guided the cheapest. The honest summary is the one the authors give: symptoms fell at lower cost, and both the clinical importance and the robustness of that are uncertain.