In Basketball Diaries, Jim Carroll documents his teenage struggles with, among other issues, drug use. Jim starts off sniffing cleaning fluids with his friends. He also drinks alcohol, consumes cough syrup, and smokes marijuana. In general, Jim seems to constantly need new thrills. These thrills include various crimes, like smashing windows and stealing food. They also include lots of sexual experimentation such as masturbating on the roof of his apartment building at night.
Overall, it’d be safe to describe Jim’s character as pleasure-seeking and lacking boundaries and discipline. He and his friends do whatever they want, even if it harms things that they care about, like basketball.
Jim’s weakness for sensation and intoxication eventually lead him to heroin. Jim has a fair amount of moxie and confidence. He believes that he can use heroin without becoming addicted. However, by the summer of 1965, Jim realizes that his “heroin habit is tightening more and more around” him. Jim is sentenced to a juvenile prison for possessing heroin. After he gets out, Jim uses heroin again. Later, a decision to quit heroin cold turkey results in Jim stealing heroin from a friend and shooting up again.
By the end of the memoir, Jim explains his heroin addiction by citing an observation from his friend Brian Browning. Brian notes that heroin users start to look fetuses. This leads Brian to conclude that heroin addiction is not separate from a desire to return to the safe bliss of the womb. Jim echos this thesis when he ends his memoir with the statement, “I just want to be pure.”
In this sense, Jim’s use of heroin could be his way of coping with the impure world around him. Jim has to deal with constant predation. His friends and his own basketball coach reinforce this parasitic, unhealthy environment. Perhaps if Jim hadn’t grown up in New York City with a single mom, maybe if he had been raised by two parents in a tranquil suburb, he wouldn’t have become addicted to heroin. Then again, many teens have faced circumstances similar to Jim’s—or worse than Jim’s—and they didn't become addicted to heroin.