53-year-old Jeffrey Blais was killed instantly when his car collided with another.
Blais was driving north in the southbound lane of the Interstate.
The other driver, is a 32-year-old Shannon Casey from Portland.
The nursing student remains in critical condition at a Lewiston hospital.
State Police trooper Jeffrey Beach say Blais struggled with lifelong mental illness, and their investigation suggests that condition played a role in the accident.