Recent evidence suggests that genetic variations in the proteins that facilitate drug metabolism can identify which patients benefit from which treatment. This translates to a reduction in side effects and better efficacy of medication, thereby reducing the suffering for the individual patient and quicker recovery. This proposed work will determine which individual patient characteristics, including pharmacogenetics, influence medication response, allowing for the construction of novel models and algorithms for personalized medication prescription. This will include an initial investigation of pharmacogenes, genes that are known to have some impact on medication response. The large datasets that comprise the UK Biobank are a key component to the development of this algorithm and will be used in conjunction with big data from the Finnish Biobank as part of the larger PSY-PGx project (https://www.psy-pgx.org/PSY-PGx). Altogether, we anticipate the project lasting 60 months. Ultimately, this project tackles the expected growth in mental illness in the EU, benefit millions of patients and make for a healthier population leading to cost reductions.