Investigation of polymorphism in the MDR1 gene and antidepressant-induced mania.

The involvement of the multi-drug-resistant 1 P-glycoprotein gene (MDR1 P-gp) in the transport of antidepressants across the blood-brain barrier makes it a good candidate for the prediction of antidepressant response and side effects. We investigated the role of the MDR1 P-gp gene in predicting the induction of mania in bipolar patients (BP) treated with proserotonergic drugs. Participants met the DSM-IV criteria for BP or BPII and had at least one depressive episode treated with proserotonergic antidepressants. The first group (n=26) included patients with at least one DSM-IV manic/hypomanic episode developed during antidepressant treatment; the second group (N=29) included patients with no antidepressant-induced switches. The common polymorphism of the MDR1 was genotyped for both groups and comparison was made with respect to the presence/absence of induced mania between the two groups. No association between antidepressant-induced mania and the MDR1 alleles or genotypes was found (?²=1.85, 2?df, P=0.39; ?²=0.13, 1?df, P=0.72).The Pharmacogenomics Journal (2003) 3, 297-299, doi:10.1038/sj.tpj.6500196 [ABSTRACT FROM AUTHOR]