Background

Internet-based cognitive behavior therapy for depression has been tested in several trials but there are no internet studies on behavioral activation (BA), and no studies on BA over the internet including components of acceptance and commitment therapy (ACT). The aim of this study was to develop and test the effects of internet-delivered BA combined with ACT against a waiting list control condition as a first test of the effects of treatment.

Methods

Selection took place with a computerized screening interview and a subsequent semi-structured telephone interview. A total of 80 individuals from the general public were randomized to one of two conditions. The treatment lasted for 8 weeks after which both groups were assessed. We also included a 3 month follow-up. The treatment included interactive elements online and a CD-ROM for mindfulness and acceptance exercises. In addition, written support and feedback was given by a therapist every week.

Results

Results at posttreatment showed a large between group effect size on the Beck Depression inventory IId=0.98 (95%CI=0.51–1.44). In the treated group 25% (10/40) reached remission defined as a BDI score≤10 vs. 5% (2/40) in the control group. Results on secondary measures were smaller. While few dropped out from the study (N=2) at posttreatment, the average number of completed modules was M=5.1 out of the seven modules.

Limitations

The study only included a waiting-list comparison and it is not possible to determine which treatment components were the most effective.

Conclusions

We conclude that there is initial evidence that BA with components of ACT can be effective in reducing symptoms of depression.