[Combination therapies in antidepressive drug refractory depression--an overview]

Despite the availability of a wide range of effective antidepressant drugs, nearly 30% of depressed patients fail to respond to antidepressant treatment. Various pharmacological strategies have been developed to treat such refractory depression, of which augmentation therapies are one of the most important. This article reviews both benefits and risks of all known augmentation therapies. Among these treatment strategies the efficacy of lithium augmentation is very well documented by a large number of controlled studies - lithium augmentation can therefore be recommended in depression refractory to antidepressant treatment. The efficacy of triiodothyronine (T3) augmentation and the combination of different antidepressants - like a TCA-MAOI combination - is described in a large number of case reports and uncontrolled studies; the number of placebo controlled double blind studies, confirming the efficacy of these treatment strategies, is however relatively small. T3 augmentation and combined antidepressant treatment may therefore be considered in the treatment of refractory depression; in contrast to lithium augmentation these combination therapies are however only second-line strategies. Other augmentation therapies (TCA + stimulants, TCA + reserpine, TCA + yohimbine, TCA + fenfluramine, SSRI + buspirone) are very interesting clinical research strategies, but don't have too much importance in clinical practice at the moment.