It is important that antidepressants, now increasingly used in ambulatory treatment of many patients, should not be detrimental to cognition and memory. It is difficult to assess these effects. One must make a distinction between the direct effects of antidepressants on cognition, related to their intrinsic properties, and indirect effects secondary to mood improvement. The tests used in studies essentially focus on psychomotricity and do not accurately evaluate the effects on cognition itself. Indeed, there are different kinds of memory which would require specific investigations. It has nevertheless been demonstrated that acute administration of sedative antidepressants with a marked anticholinergic component are detrimental to the memory processes. However, following prolonged administration, tolerance may develop within 1 to 3 weeks. Some antidepressants, however, especially serotonergics, do not cause any disturbances of memory. In depressed subjects, it seems that, overall, long-term antidepressant treatment improves cognitive functions. This effect is due to the combination of drug tolerance and of the indirect effects secondary to mood improvement. Elderly subjects appear to be more sensitive to the detrimental effects on memory and they develop drug tolerance more slowly. Lastly, two studies have reported that serotonin re-uptake inhibitors might have beneficial effects on memory disorders secondary to acute or chronic alcohol abuse.