Since the discovery of the first antidepressive compounds, very few progress have been made for the efficacy of these drugs. All the antidepressants, even the more recent of them, are efficient only in 60 to 75% of the depressive disorders treated. Many studies have been conducted to define clinical or psychological predictive factors of the response to antidepressants. Emphasis was carry mostly on the clinical characteristics of the depressive disorder and the importance of "endogenous" features for the response to treatment, have been well established. Some works have also emphasized the importance of personality disorders and environmental disturbances for the issues of treatment. More recent works aim to define the characteristics of the best responders to more selective antidepressive compounds. But, it is still very difficult today to define precisely what are the clinical or psychological features which are specifically responsive to antidepressive drugs.