ABCB1 and major depressive disorder: The tool subdivided the disorder based on 18 genes associated with ‘Anxiety’ but not ‘Depression with alcohol use’ and two associated with ‘Depression with alcohol use’ and not ‘Anxiety.’ Evaluation of Oxtr and Abcb1 genes in anxiety and alcohol assays, along with representatives of the 18 anxiety genes not associated with depression and alcohol dependence, will test the validity of this classification.