Psychiatric pharmacogenetics is mostly two genes, CYP2C19 and CYP2D6, plus two HLA alleles. Here is what the evidence supports, how to call those genes from whole-genome data with PharmCAT and Cyrius, and where the commercial panels overreach.
What pharmacogenomic panels like GeneSight measure, what the trial data show, how to read CYP2D6 and CYP2C19 from your own genome, and what serum drug levels can and cannot tell you.