Yes, in the first book a character tries to OD with painkillers and later on with cocaine, and in the second book a character uses prescription meds that aren’t prescribed to them. Alcohol is also in both books.
A character is implied to have sex with someone who they are literally incapable of saying no to - their emotions are subjected to the same manipulation. It does not necessarily read as a sexual assault, nor is it ever labeled as one in the book, but, objectively, it is.