Dr. Bergen’s research spans aging and psychiatric and substance use disorders, and relies upon collaboration with colleagues and institutions from multiple sectors.

Dr Bergen and colleagues have demonstrated effects of combined use of prescription analgesics and sedatives and the use of prescription analgesics on frailty in the Health and Retirement Study. Dr Bergen contributes to the Price Foundation (eating disorders) and Psychiatric Genomics consortia research. Dr Bergen has led or contributed to pharmacogenetic meta-analyses of cessation trials, genomic meta-analyses of smoking behaviors and prediction modeling of the nicotine metabolite ratio in multiethnic cohorts, and analyses of time-dependent effects of buprenorphine treatment in opioid use disorder treatment trials.