Joanna, a 23-year-old college student, presents to the clinic for her first prenatal visit. During the visit, she mentions occasional recreational drug use and expresses concern about the health effects of cannabis. She says she uses cannabis socially on weekends and perceives it as harmless because it’s legal in her state. She denies using other substances like cocaine, heroin, or prescription drugs. Her physical examination is unremarkable, and she appears healthy. During the discussion, she asks: “Is cannabis really the most commonly used drug, or are there other substances more popular?” Which of the following is the most commonly used illicit substance in the United States?
