The following is a summary of “A randomized controlled trial of a therapist-guided online intervention for depressed adults and its utility as an adjunctive to antidepressants and psychotherapy,” published in the February 2025 issue of BMC Psychiatry by Heinrich et al. 

Internet-based interventions (IBIs) offer a low-threshold treatment for depression. Limited evidence exists on their add-on effect for individuals already receiving antidepressants or psychotherapy. 

Researchers conducted a retrospective study to evaluate the effectiveness of IBIs for depression. 

They conducted a parallel, two-arm RCT with a 1:1 allocation ratio and simple randomization. Eligible adults (≥ 18 years) with mild to moderately severe depression (BDI-II ≥ 14, PHQ-9 ≤ 19) were assigned to either the intervention (INT) arm or an unstandardized care-as-usual (CAU)-arm. The INT-arm received a 7-module CBT-based IBI. The primary endpoint was depressive symptom load 9 to 11 weeks after randomization, with secondary endpoints including anxiety, self-efficacy, and perceived social support. Effects were reported for the entire sample (N = 1899) and subgroups: stand-alone IBI (n = 1408), IBI + antidepressants (n = 367), IBI + psychotherapy (n = 73), and IBI + antidepressants and psychotherapy (n = 51). 

The results showed 62.5% of individuals in the INT-arm accessed all treatment modules within 11 weeks. INT-arm individuals had significantly lower depressive symptoms (PHQ-9: −2.5, 95% CI [−2.9, −2.0], d = −0.7; BDI-II: −5.3, 95% CI [−6.5, −4.1], d = −0.8) and higher rates of ≥50% symptom improvements (PHQ-9: 38.5% vs 14.3%; BDI-II: 44.6% vs 14.8%) compared to CAU. Secondary outcomes favored INT (d = 0.18 to 0.62). Rates of deterioration were low in the INT-arm (PHQ-9: 4.1%; BDI-II: 3.4%), with 10.5% reporting side effects. No significant differences were found for individuals using IBI as an add-on to psychotherapy. 

Investigators found that providing access to the therapist-guided, cognitive-behavioral IBI improved mental health outcomes, whether used as a stand-alone or add-on intervention. This supports the consideration of IBIs as a low-threshold treatment option for individuals with depression. 

Source: bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-025-06564-2