Disclosed are methods for treating disorders associated with dopamine receptor activity. In some embodiments, the disclosed methods include assaying the nucleic acid from a subject for the genotype of the variable number tandem repeats (VNTR) polymorphism in the dopamine transporter DAT1/SLC6A3 gene, wherein when one or two alleles for 9 tandem repeats is detected a dopamine partial agonist is administered to the subject and wherein when two alleles for 10 tandem repeats is detected a dopamine modulator is not administered to the subject. Also provided are methods for treating disorders associated with dopamine receptor activity that include genotyping a subject with respect to a COMT polymorphism, a DRD2 polymorphism, a 48-base-pair VNTR polymorphism in DRD4 exon 3, and/or a ANKK1 TaqA1 polymorphism, and methods for detecting susceptibility to dopamine modulator therapy for conditions associated with dopamine receptor activity.
