Mueller is actively involved in developing pharmacogenetics treatment recommendations for physicians and patients through his close collaboration with international organizations such as the Clinical Pharmacogenetics Implementation Consortium (CPIC), the International Society of Psychiatric Genetics (ISPG) and the Pharmacogenetics Research Network (PGRN).
Mueller’s research goals have been to investigate genetic causes of response and side effects to psychiatric medications on which he published more than 200 articles. This line of research aims to significantly improve the treatment of psychiatric conditions and to lessen the burden of medication side effects and avoid adverse drug-drug interactions.