Major depressive disorder (MDD) is a highly prevalent and debilitating mental disorder with a high lifetime prevalence of 16-20%. Particularly for people with low socio-economic status, the existing and effective treatment options are hard to reach and show weaker effectivities. There is a potential to ameliorate depressive symptoms and improve quality of life in persons with mild-to-moderate depression by providing access to stimulating computerized trainings. Single computerized trainings that target depressive symptoms have been tested in laboratory and clinical settings so far. To date, innovative market access and confirmatory studies are missing for a large-scale implementation of such trainings. Thereby, the present work will foster a digitalized training paradigm (Paced-Auditory Serial Addition Task; PASAT) which was previously shown to reduce depressive symptoms, but in a novel innovative and gamified form on a tablet-PC handed out to participants. Different versions of the same training paradigm that comprise additional game elements will be compared. The feasibility study will gather data on effect size estimates of symptom severity reduction, user experience and usage in an ecological valid setting.

Inclusion Criteria:

• Full age (> 18 years old)
• Consent
• German mother tongue
• Presence of mild-to-moderate depressive symptoms (MADRS > 10 and < 34 and confirmation of depressive symptoms in M.I.N.I. diagnostic interview)
• Stable or no medication with antidepressant drugs or other psychoactive agents (at least for 6 weeks)
• No or current psychotherapy

Exclusion Criteria:

• Presence of schizophrenia / psychotic disorder (according to M.I.N.I. diagnostic interview)
• Cognitive impairment
• Epilepsy