Antidepressants can sometimes cause agitation, particularly in patients with bipolar disorder, but concern about such effects is generally limited to the first weeks and months of treatment.Demonstration of the occurrence of agitated dysphoria after loss of response to an antidepressant following continuous administration through 7 years of euthymia; with a worsening on dose increase; and recurrence of agitation on re-exposure 1 year later; in a patient whose previous dysthymia and recurrent depressions had no recognizable manic or hypomanic features.Only when the antidepressant was removed, twice, was treatment an atypical antipsychotic and lithium effective.An antidepressant which has been effective for as long as 7 years may still carry risk of inducing agitated dysphoria, even in apparently unipolar depression. In some patients, clinical vigilance for antidepressant-induced dysphoria may be warranted for extended periods of time.