Antidepressants are mainly used to treat mental illnesses. Traditional antidepressants mainly target monoamine neurotransmitters, but these drugs are slow to be effective and cannot meet clinical needs. Recently, therapeutics have been developed that depart from the traditional monoamine hypothesis and focus on the glutamatergic, GABAergic, opioidergic, and inflammatory systems. In recent years, great progress has been made in the development of new antidepressants, some of which have been applied in clinical practice. This article mainly summarizes the research mechanisms and treatment programs of new antidepressants, and briefly reviews common rapid-acting antidepressants.