Affective disorders are the most common mental illnesses and are often comorbid with other mental disorders (anxiety disorders, addictions, personality disorders).

Due to the risk of suicide during depressive periods, they are classified as fundamentally life-threatening. However, the impact on the psychosocial integration of the patients as well as the burden on the relatives is often also very high. Unipolar depression alone now ranks first among causes of loss of “healthy life years” worldwide according to the DALY (Disability-Adjusted Life Year) score. Affective disorders cause 7% of the total burden of disease in Europe.

The phase of acute antidepressant therapy, which aims at complete remission, leads directly into maintenance therapy. The mechanism of action of almost all antidepressants on the market today is based on the monoamine deficiency hypothesis of depression formulated in the 1960s. According to this hypothesis, antidepressant drugs correct the postulated cerebral deficit of serotonin and norepinephrine and induce mood elevation via downregulation of the receptors. The efficacy of antidepressants is 60-70%, i.e., about one-third of patients do not respond to initial drug therapy. In these cases, a switch to another agent or the initiation of adjuvant measures is therefore necessary.¹

¹ Fleischhacker & Hinterhuber. Textbook of Psychiatry. Springer Vienna New York 2012, 154-177.