The goals for acute treatment of depression are full symptom remission and return to baseline functioning. Among patients undergoing primary care treatment for depression, 60 to 80 per cent achieve symptom remission. Remission typically is defined as having normal mood and minimal symptoms, but it is best evaluated using a rating scale (e.g., a score within the normal range on the PHQ-9, Hamilton Depression Rating Scale or Beck Depression Inventory).
Antidepressant medications are the first-choice treatment for moderate to severe depression. (For treatment of mild to moderate depression, see “Psychotherapy.”) The newer antidepressants—selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), bupropion, mirtazapine and vortioxetine—are all first- line medications, offering improved tolerability and a better safety profile compared with tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) (Bezchlibnyk-Butler et al., 2014; Stahl, 2017). The following tables summarize antidepressant characteristics.