Nicholas Ray - Bigger Than Life (1956)

Schoolteacher Ed Avery, without telling his family, is moonlighting as a part-time taxi dispatcher to make ends meet, his wife Lou Avery who suspects his prolonged absences means that he's having an affair. Thinking that his occasional acute attacks of pain are just him being overtired, Ed, after blacking out due to one of those attacks, is taken to the hospital. While that hospitalization leads to a relieved Lou learning about the existence of that second job and not of an affair, they further learn that the pain Ed is experiencing is due to a disease that will most-likely take his life within the year. His medical team recommends an experimental drug, cortisone, that could save his life, something that he would have to take for the rest of his life if he survives. While the drug therapy does save his life, Ed, without anyone around him knowing that he is doing so, begins to abuse its use, which has the side effect of extreme mood swings, something that Lou, their son Richie, and Ed's best friend and fellow teacher Wally Gibbs notice, Lou who doesn't want to address it in fearing that a deterioration in Ed's mental health would mean his job, and also in the knowledge that the cortisone saved his life without knowing that he has been abusing it. But when Ed's further abuse of the drug leads to psychosis, Lou cannot avoid dealing with it anymore, the question being if it is too late for Ed and/or their family in Ed's psychosis having potentially deadly consequences.