An adaptation of the best-selling novel Brain on Fire with Dakota Fanning in the starring role has been in development for over a year now. Based on the harrowing memoir, Brain on Fire: My Month of Madness by Susannah Cahalan, the film will follow a woman’s quick and sudden descent into insanity as the result of a mysterious neurological illness. Thomas Mann (Project X) is in negotiations to star as Fanning’s boyfriend, Stephen, and Jenny Slate (Obvious Child) is also in talks to take an undisclosed role, according to Deadline. 

Charlize Theron (Snow White and The Huntsman), who will also appear in the film, is producing as a part of her production company, Denver and Delilah Films. Gerard Barrett (Glassland) wrote the script and will also direct, with the movie beginning filming this July in Vancouver and New York.

Mann has been working steadily since starring in 2012’s Project X, booking numerous supporting roles in such films as Beautiful Creatures and Hansel & Gretel: Witch Hunters. 2015 looks like it will be his year of recognition, however, after starring in the multiple Sundance award-winning film Me and Earl and The Dying Girl, co-starring in Kristen Wiig‘s (Bridesmaids) Welcome to Me and his other Sundance film The Stanford Prison Experiment, as well as in the Hailee Steinfeld teen action-comedy Barely Lethal.

Slate, who received undying critical praise for her performance in last year’s Obvious Child, has been all over the comedy world, acting in various television series like Parks and Recreation, Married, and Saturday Night Live. The drama of Brain on Fire will likely see Slate in a starkly different role than what her audience has been accustomed to seeing from her. Before Brain on Fire is released, however, she will appear in the drama Digging for Fire as well as the comedies My Blind Brother – with her Parks and Rec co-star Adam Scott – and Joshy with Thomas Middleditch (HBO’s Silicon Valley).