Combined treatment strategies in psychiatry.

Combination drug regimens are commonly employed in the treatment of psychiatric disorders. Virtually all classes of psychotropic medications have been used in combination and for a variety of indications. Some drug combinations are thought to be synergistic, and others are used to treat different target symptoms. Combination therapies are used as the primary treatment for certain disorders (antipsychotic-antidepressant combinations in psychotic depression); as adjunctive treatment for patients refractory to initial drug therapy (lithium augmentation in refractory depression); and as treatment for the emergence of a secondary disorder (depression in a schizophrenic patient). Since combination treatment may increase the risk of adverse reactions through either pharmacodynamic or pharmacokinetic interactions, knowledge of these interactions and their possible adverse effects is crucial.