We also learn that Kitty had a drug problem, but we don't see her using any. Nicky smokes some sort of drug, while Sandra has a drink and Nicky and Jerry have beer in front of them. Jerry smokes a few joints while working at the typewriter. People have drinks at a party. Jerry takes more drugs when he learns that Sandra is pregnant.
People drink in a club.
Some guys on a bus share what appears to be a joint. We see several glimpses of needles going into arms, and in one scene, Jerry sticks the needle into his jugular, and we see a little blood from that. We hear Jerry throw up in a bathroom. Jerry has a slightly bloody scrape on his face after being beaten up. Obviously Jerry has both for becoming a drug addict and hiding it from Sandra.