[2] Johannisson's research focused on the history of medicine from a societal perspective.

Her doctoral dissertation from 1974, Magnetisörernas tid, dealt with the 18th and 19th century phenomenon called animal magnetism.

She was appointed Professor of History of Science and Ideas at Uppsala University in 1996, and held the chair until her retirement in 2011.

[1] She was also an author of popular scientific books, with 15 published titles, four of which were shortlisted for the August Prize.

[4] Johannisson was married twice, first to the literary scholar Stefan Mählqvist, with whom she had two sons.