Red Desert (movie, 1964)

Amid the modern wastelands and toxic factories of Italy, wife and mother Giuliana desperately tries to conceal her tenuous grip on reality from those around her, especially her successful yet neglectful husband, Ugo. Ugo's old pal, Corrado, shows up in town on a business trip and is more sensitive to Giuliana's anxieties. They begin an affair, but it does little to quell Giuliana's existential fears, and her mental state rapidly deteriorates.