The use of antidepressants for long-term treatment of recurrent depression: rationale, current methodologies, and future directions.

Present strategies for long-term treatment of major depressive disorder stem from the following three observations: the high frequency of recurrent depression, the length of a depressive episode, and the ability of antidepressants to prevent recurrences. Two different phases of long-term antidepressant treatment are now considered: continuation and a "true" maintenance or prophylactic phase. Moreover, it seems important to discriminate between relapse (from a previous episode) and recurrence (a new episode). However, there are some unresolved questions, such as (1) the duration of antidepressant treatment, (2) the type and posology of antidepressants to be used, and (3) some methodological aspects, such as the choice of comparators, definition of response, and combination with other therapies. This paper deals with all of these aspects, finally suggesting different prophylactic strategies in relation to factors like severity of symptoms, frequency of episodes, compliance, and susceptibility to side effects.