Its a type of Reggie Perrin.
Mental health problems that make people up and leave with no warning are no fun for anyone, thats a deep unhappiness, a complete shut down, poor fucker, his wife will be having a real shit time too.
You always hope its cos his life was bad and he had the strength to say “Fuck this shit” and rode off into the sunset, leaving a note to never return, that somehow the people around him deserved it but usually its just old as the hills dark depression.
But then who hasn’t had days when they’ve considered doing exactly what he did? When I was teenage I crashed my car into a lamppost (dog ran out) and was going to get grief for being late, I walked towards where I worked and carried on walking.. fuck that shit!