With the tricyclics, selective serotonin reuptake inhibitors (SSRIs) and other substances, we now have available a range of medications for the treatment of depression and other psychological disorders (e.g. anxiety, panic). Nevertheless, only some of the patients experience a remission of their depressive symptoms. The occurrence of side effects and the only modest level of effectiveness result in inadequate compliance on the part of the patient. With venlafaxine and duloxetine two representatives of the selective serotonin and noradrenaline reuptake inhibitor (SSNRI) class of antidepressants are now available. SSNRIs have a dual effect coupled with high selectivity. The present article the extent to which this particular action mechanism results in an improved clinical efficacy and tolerability profile of the SSNRIs, in particular in comparison with SSRIs.