[Delay in the effect of antidepressive agents: pharmacologic approach].

A paradox which is not resolved in the use of antidepressants (ATD) is that in pharmacological studies of animal models of depression and in neurochemical studies, the onset of activity of all drugs is extremely rapid, whereas in human clinical practice the onset is delayed (15 days). An attempt is made to explain this in 3 ways, involving the synapse, transduction mechanisms, and cognition. Analysis of the impact of all ATDs shows that we are confronted with slow adaptive processes which are correlated with the delay observed in clinical practice. The interest of such considerations is that they may give rise to alternative therapies which are able not only to accelerate response, but also to increase it.