GADL1 variant and medication adherence in predicting response to lithium maintenance treatment in bipolar I disorder

BACKGROUND: Genetic variants and medication adherence have been identified to be the main factors contributing to lithium treatment response in bipolar disorders. AIMS: To simultaneously examine effects of variant glutamate decarboxylase-like protein 1 (GADL1) and medication adherence on response to lithium maintenance treatment in Han Chinese patients with bipolar I (BPI) disorder. METHOD: Frequencies of manic and depressive episodes between carriers and non-carriers of the effective GADL1 rs17026688 T allele during the cumulative periods of off-lithium, poor adherence to lithium treatment and good adherence to lithium treatment were compared in Han Chinese patients with BPI disorder (n=215). RESULTS: GADL1 rs17026688 T carriers had significantly lower frequencies of recurrent affective episodes than non-T carriers during the cumulative period of good adherence, but not during those of poor adherence. CONCLUSIONS: GADL1 rs17026688 and medication adherence jointly predict response to lithium maintenance treatment in Han Chinese BPI patients. DECLARATION OF INTEREST: None. COPYRIGHT AND USAGE: © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.