Depression is one of the most common diagnoses in psychiatry and forms the largest patient group of the affective disorders. It is also the typical serotonin related diagnosis, making it one of the first disorders studied using ATD. Studies have shown that ATD can induce relapses in patients in remission from major depression and other psychiatric disorders (Moore et al, 2000, Neuropsychopharmacology); it can also lower mood in healthy patients with a family history of depression (Benkelfat et al, 1994, Archives of General Psychiatry); some authors even suggest using ATD as a predictive test for personalized antidepressant treatment (Toker et al, 2010, Israeli Journal of Psychiatry & Related Sciences). The following segment will give an overview over the most recent research into depression using ATD.