Distinction between relapse and recurrence is a major difficulty in st
udies assessing the efficacy of long term antidepressant treatment. A
four to sir months symptom-free period is required to talk of recovery
from depression and plan a preventive treatment i.e. prevention of re
currence. Compounds are not selected according to their biochemical pr
ofile; the most recent antidepressant drugs were studied in that indic
ation through long term controlled trials. In unipolar patients, recen
t studies favour the prescription of high doses of-antidepressant drug
s during at least five years. In bipolar patients, combination of long
term antidepressant to lithium treatment may be of benefit to patient
s whose index episode was of depressive type, but appears useless in o
ther cases. In all cases, joint psychotherapy and the quality of the r
elationship between the patient and the prescribing physician influenc
e compliance and outcome. Dysthymia, panic disorder and obsessive-comp
ulsive disorder constitute other acknowledged cases for long term pres
cription of antidepressants. These indications remain empirical till c
ontrolled trials have not specifically assessed each antidepressant co
upound.