[Memory, emotional status and affective valence. Critical review]

Literature emphasizes that affective factors such as the subject's emotional state or the emotional tone of the information influence memory: The present review is focused on two critical phenomena: 1) "State-Dependent Memory Effect" (or State-Dependent Recall) i.e. material memorized in a given emotional state is more easily recalled in the same emotional state. 2)"Mood Congruence Effect" where a subject memorizes more easily the material whose emotional tone is congruent to his own emotional state than the material having a non congruent emotional tone. By and large, studies using experimentally induced mood (generally happy or sad) have questioned the "State-Dependent Memory Effect" but frequently confirmed the "Mood Congruence Effect". Very few clinical studies have investigated the "State-Dependent Memory Effect" in affective disorders as compared to the "Mood Congruence Effect". Their results are consistent with the existence of a "Mood Congruence Effect" in depression, but the experimental conditions seem to have a great importance. Hence, the effect is reduced when the subject is aware of the emotional content of the material. This cognitive process, related to the categorisation of words depending on their affective tone, allows an efficient organization of the material during encoding and seems to modulate the automatic selective processing of emotionally loaded information.