Mommy
(2014)

Diane (Anne Dorval) is a widow, living in poverty and struggling to deal with her 15 year old son Steve (Antoine-Olivier Pilon), who has ADHD and is prone to violent outbursts.

His behaviour improves when they befriend their neighbour Kyla (Suzanne Clément), a high school teacher by training who tutors him. Diane is sued by the family of someone that Steve harmed and the crisis results in Steve slashing his wrists.

When he's recovered, Diane and Kyla take him for a trip, not telling him until they've arrived at the mental hospital that Diane is having him permanently committed.

Kyla later tells Diane that her family is moving away, and their friendship is clearly over.

At the hospital, Steve is kept physically and chemically restrained, but manages to break away from his captors. He runs towards a window and appears to intend to jump through it.

Thanks Tiaga!