Depressive symptoms are common, yet only a subset of individuals receives adequate treatment. To reduce the treatment gap, several online self-help programs have been developed, yielding small to moderate effects. We developed a self-help application for mobile devices addressing depressive symptoms. The aim of this study was to evaluate its feasibility and efficacy in a sample of participants reporting a subjective need for help (a diagnosis of depression was not mandatory). We conducted a randomized-controlled trial (N = 90). The primary outcome was a reduction of depressive symptoms measured with the Patient Health Questionnaire-9 (PHQ-9). Secondary outcomes included improved self-esteem (Rosenberg Self-Esteem Scale) and quality of life (WHOQOL-BREF). The intervention group obtained access to the application for four weeks, the wait-list group received access after the post assessment. No group differences emerged in either outcome in intention-to-treat analyses. Per protocol analyses with frequent users (i.e., several times a week or more) yielded a significant moderate effect on the reduction of depressive symptoms in favor of the treatment group. However, 39% of the participants did not use the application frequently.Mobile self-help applications represent a promising addition to existing treatments, but it is important to increase patients' motivation to use them.

Cognitive deficits are common in depression and may persist following the resolution of affective symptoms. However, therapeutic strategies that successfully target cognitive impairments are lacking. Recent work has demonstrated that playing action video games leads to improvements in cognition, in particular executive function, in healthy individuals. We therefore set out to test whether playing video games can reduce symptoms associated with depression. We focussed on depressive symptoms and on rumination, since rumination is a good predictor of depression and may contribute to triggering depression. We recruited 68 clinically depressed individuals (mean age: 46 years, 47 females) that were randomized into the training group playing a fast paced action video game for 6 weeks or a waitlist control group. Before and after training participants completed online questionnaires and a neuropsychological test battery. Only participants who actually played the game were included in the analysis. The final sample consisted of n = 21 training group and n = 29 waitlist control group. The training group showed significantly higher subjective cognitive ability, as well as lower self-reported rumination at posttest in contrast to the control group (although these findings do not survive Bonferroni correction). On a subsample with cognitive performance data (n = 19) we detected an improvement in executive function (Trail Making Task A and B) in the training compared with the control group. The results show that the fast paced action video game employed in the present study improved Trail Making performance and may reduce rumination and enhance subjective cognitive ability. Future research may focus on the investigation of the precise cognitive profile of effects.