Leap Into the Void (1980)

Mauro, a judge, is worried about his older sister Marta, who took care of him since he was a boy, and now suffers from mental illness and suicidal thoughts. She seems to recover from her depression when Mauro acquaints her with Giovanni, a brilliant actor at the edge of legality. However, Mauro becomes unconsciously jealous of their relationship and tries to get Giovanni arrested.