PubMed2005
BACKGROUND: 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. METHOD: 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. RESULTS: Only when the antidepressant was removed, twice, was treatment an atypical antipsychotic and lithium effective. CONCLUSION: 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.