Antidepressant-induced mania in bipolar patients: Identification of risk factors

Background: Concerns about possible risks of switching to mania associated with antidepressants continue to interfere with the establishment of an opt imal treatment paradigm for bipolar depression. Method: The response of 44 patients meeting DSM-TV criteria for bipolar dis order to naturalistic treatment was assessed for at least 6 weeks using the Montgomery-Asberg Depression Rating Scale and the Bech-Rafaelson Mania Rat ing Scale. Patients who experienced a manic or hypomanic switch were compar ed with those who did not on several variables including age, sex, diagnosi s (DSM-IV bipolar I vs. bipolar II), number of previous manic episodes, typ e of antidepressant therapy used (electroconvulsive therapy vs. antidepress ant drugs and, more particularly, selective serotonin reuptake inhibitors [ SSRIs]), use and type of mood stabilizers (lithium vs. anticonvulsants), an d temperament of the patient, assessed during a normothymic period using th e hyperthymia component of the Semistructured Affective Temperament Intervi ew. Results: Switches to hypomania or mania occurred in 27% of all patients (N = 12) (and in 24% of the subgroup of patients treated with SSRIs [8/33]); 1 6% (N = 7) experienced manic episodes, and 11% (N = 5) experienced hypomani c episodes. Sex, age, diagnosis (bipolar I vs. bipolar II), and additional treatment did not affect the risk of switching. The incidence of mood switc hes seemed not to differ between patients receiving an anticonvulsant and t hose receiving no mood stabilizer. In contrast, mood switches were less fre quent in patients receiving lithium (15%, 4/26) than in patients not treate d with lithium (44%, 8/18; p = .04). The number of previous manic episodes did not affect the probability of switching, whereas a high score on the hy perthymia component of the Semistructured Affective Temperament Interview w as associated with a greater risk of switching (p = .008). Conclusion: The frequency of mood switching associated with acute antidepre ssant therapy may be reduced by lithium treatment. Particular attention sho uld be paid to patients with a hyperthymic temperament, who have a greater risk of mood switches.