Cognitive bias modification to prevent depression (COPE): results of a randomised controlled trial

Although efficacious treatments for major depression are available, efficacy is suboptimal and recurrence is common. Effective preventive strategies could reduce disability associated with the disorder, but current options are limited. Cognitive bias modification (CBM) is a novel and safe intervention that attenuates biases associated with depression. This study investigated whether the delivery of a CBM programme designed to attenuate negative cognitive biases over a period of 1 year would decrease the incidence of major depression among adults with subthreshold symptoms of depression.

Randomised double-blind controlled trial delivered an active CBM intervention or a control intervention over 52 weeks. Two hundred and two community-dwelling adults who reported subthreshold levels of depression were randomised (100 intervention, 102 control). The primary outcome of interest was the incidence of major depressive episode assessed at 11, 27 and 52 weeks. Secondary outcomes included onset of clinically significant symptoms of depression, change in severity of depression symptoms and change in cognitive biases.

Adherence to the interventions was modest though did not differ between conditions. Incidence of major depressive episodes was low. Conditions did not differ in the incidence of major depressive episodes. Likewise, conditions did not differ in the incidence of clinically significant levels of depression, change in the severity of depression symptoms or change in cognitive biases.

Active CBM intervention did not decrease the incidence of major depressive episodes as compared to a control intervention. However, adherence to the intervention programme was modest and the programme failed to modify the expected mechanism of action.