Methods for selecting medications

A processor programmed to perform operations comprising:

• receiving a patient's genotype for a panel of at least three genes comprising cytochrome P450 gene CYP2D6, cytochrome P450 gene CYP2C19 and serotonin transporter gene 5HTTR, wherein
• (a) the cytochrome P450 CYP2D6 alleles comprise one or more of the fully functional alleles *1A, *2N, and *35, the partially functional allele *10, and non-functional alleles *3, *4, *5, *6, *7, *8, and *12,
• (b) the cytochrome P450 CYP2Cl 9 alleles comprise one or 40 more of the fully functional alleles *1A and *1B, and non-functional alleles *2A, *2B, *3, *4, *SA, *SB, *6, *7 and *8, and
• (c) the patient's genotype at the serotonin transporter gene 5HTTR is determined at the two alleles consisting of the short (s) and long (l) forms of the 5HTTR gene, wherein the long form of the 5HTTR gene comprises a 44 base pair insertion in the promoter region, and the short form of the 5HTTR gene comprises a 44 base pair deletion in the promoter region;
• assigning a metabolic phenotype to each genotype of each cytochrome P450 gene, wherein the metabolic phenotype is assigned according to the number of functional, partially functional, or nonfunctional cytochrome P450 alleles in the genotype, the phenotypes comprising poor (P), intermediate (I), and extensive (E), and a phenotype of poor (P) comprising individuals who are homozygous or compound heterozygous for a partially functional or non-functional cytochrome P450 allele, a phenotype of intermediate (I) comprising individuals who are heterozygous, and a phenotype of extensive (E) comprising individuals who do not have any inactivating polymorphisms, deletions, or duplications among their cytochrome P450 alleles;
• outputting a psychotropic medication based upon the patient's cytochrome P450 genotype and 5HTTR genotype.