Brogan graduated from Cornell University Medical College in Psychiatry, and has a B.S. in Systems Neuroscience from MIT. She uses the title of "holistic psychiatrist". Medical fraud researcher Peter Heimlich points out Brogan appears to have failed to maintain certification with the American Board of Psychiatry and Neurology, according to the association's database. She removed her claim of being certified in psychiatry and psychosomatic medicine from her website after Heimlich's research was made public. Brogan wrote about health on Gwyneth Paltrow's Goopretail website and was featured on expert panels at several Goop events.
Brogan promotes the belief that human diseases are caused not by infectious agents, but rather by psychological factors. She mocks the well-established notion of "little invisible pathogens, you know, that randomly jump around from person to person". In March 2020, during the COVID-19 pandemic, Brogan indicated at length that, in her opinion, the virus may not exist. According to her, it's rather the fear of a virus that makes people sick and die. She referred her followers to the pseudoscientific claims of Joseph Mercola and Ryke Geerd Hamer on the topic. Twitter, Facebook, Vimeo and Instagram removed Brogan's videos, as part of their efforts to limit the spread of misinformation during the epidemic, a move Brogan described as "censorship". Brogan's claims about the cause of diseases, as have Hamer's and Mercola's, have been debunked by medical experts as dangerous misconceptions. On that occasion and others prior, she accused the government of being controlled by pro-vaccination "elites" with a sinister agenda. She suggested the pandemic was a ploy by the United States government to force vaccination on people and usher in totalitarian measures. Investigator Benjamin Radford attributes Brogan's theories to a wider phenomenon of self-styled populist health experts inciting people to reject science and embrace their own theories. In a similar vein, Brogan attributed the death of AIDS patients not to HIV, but to treatments meant to fight it. Even though the link between HIV and AIDS is clearly established by medical research, she calls it an "assumption". She also defended the disproven belief that intestinal bacteria cause depression; Brogan invites people to stop taking antidepressants and use the techniques and products from her website instead. Through her website, Brogan offers a subscription-only "lifestyle medicine" community space and access to self-improvement training resources. She also promotes many of the usual erroneous claims against vaccines, notably that the immunity gained from surviving an infectious disease is superior to the one generated by being vaccinated. She also denies polio was eradicated by vaccination. Despite coffee enemas being long discredited as medical procedures, Brogan promotes them for depression.
