People have had to deal with desperate, impoverished lives throughout all of history, and usually managed to muddle through without committing suicide en masse

People have had to deal with desperate, impoverished lives throughout all of history, and usually managed to muddle through without committing suicide en masse or dying of drug addiction/overdose. People in the past most likely managed to deal with their poor circumstances because of social factors (i.e., they weren't lonely). Throw in an epidemic of loneliness and social isolation, as is common in modern urban/suburban life, and it's easy for even people in not-so-horrible circumstances to break under the strain.