Flint is known for his research on the genetics of complex traits in mice and major depressive disorder in humans. In 2015, he and his colleagues published a study that was the first to link two genetic variants to this disorder.[6] In 2016, he left his post as director of the Psychiatric Genetics Group at the University of Oxford's Wellcome Trust Centre for Human Genetics to join UCLA. Upon doing so, he became one of four directors of UCLA's Depression Grand Challenge, which aims to conduct a study of 100,000 people to search for genetic risk factors for depression. This study is intended to be the largest genetic study of a disorder ever conducted in humans.[7]
He serves on the editorial board for the journal Current Biology.[8]