[Limits of efficacy and tolerance of antidepressive medications]

About 35 to 40 % of all depressions still resist antidepressants either imipraiminic or M.A.O.I. In some cases recourse to E.S.T. may even be required. Recurrent monopolar depressions, hypochondriac depressions in aged patients, depressive states in psychotic evolutions are among the most difficult to be treated. Some factors of resistance (such as side benefits) happen in reactive and neurotic depressions and are independent of the pharmacological action. Among the problems of tolerance that have not been completely solved it is interesting to note, in the case of the tricyclics, confusional states and the dangers of toxicity for the heart, and in the case of M.A.O.I. the numerous forbidden associations (such as morphine-like substances, tricyclics, sympathicomimetic drugs...). The new compounds with supposed antidepressive action, such as hypothalamic factors (T.R.H. or M.I.F.) or the 5 H.T.P. represent research hypotheses rather than safe ground of treatment. The problems of maximal doses and long-acting antidepressants are also discussed.