Effects, Adherence, and Therapists' Perceptions of Web- and Mobile-Supported Group Therapy for Depression: Mixed-Methods Study.

Background: Blended group therapy (bGT) has been investigated a several times for anxiety and depression, but information on patients' adherence to and therapists' perception of the novel format is nonexistent. Furthermore, many studies investigated mainly female and highly educated populations, limiting the validity of previous findings.

Objective: This study aimed to reduce the gaps and limitations of the previous findings by evaluating an integrated internet- and mobile-supported bGT format.

Methods: A total of 27 patients diagnosed with major depression (14/27, 52% female and 7/27, 25.9% compulsory education) participated in a 7-week treatment at a university outpatient clinic. Furthermore, 8 novice therapists participated in semistructured interviews and a subsequent cross-validation survey.

Results: Primary symptom reduction was high (d=1.31 to 1.51) and remained stable for the follow-up period. Therapists identified advantages (eg, patient engagement, treatment intensification, and improved therapeutic relation) and disadvantages (eg, increased workload, data issues, and undesired effects) of bGT. The required online guidance time was 10.3 min per patient and week, including guidance on exercises (67% or 6.9 min) and intimate communication (33% or 3.4 min). Concerning patients' adherence to bGT, tracked completion of all Web-based and mobile tasks was high and comparable with group attendance.

Conclusions: Results suggest high feasibility of bGT in a gender-balanced, moderately educated sample. bGT provides group therapists with tools for individual care, resulting in an optimization of the therapy process, and high completion rates of the implemented bGT elements. The limited work experience of the involved therapists restricts the study findings, and potential drawbacks need to be regarded in the development of future bGT interventions.