['The aim of this study was to give further support to the available evidence that mood stabilizers can reduce the risk of antidepressant-induced maniform switch phenomena in bipolar I depressed patients.', 'Medical records of 158 patients with bipolar I depression were analysed for the incidence of switch phenomena from depression to maniform states (mania and hypomania). The impact of mood stabilizers on reducing the risk of switching was analyzed using logistic regression analyses.', 'Maniform switches during inpatient treatment were observed in 39 (25%) patients out of the total of 158 patients. Results indicate that especially patients receiving tricyclic antidepressants are at risk of switching to maniform states. This risk was shown to be significantly less when patients also received a mood stabilising medication (lithium, carbamazepine or valproic acid).'] Do mood-stabilisers reduce the risk of developing antidepressant-induced maniform states in acute treatment of bipolar I depressed patients?