Irony of Consent
Although the Diarist freely chooses to experiment with a variety of illegal drugs, her first drug experience and the pivotal one that disrupted her sobriety were not consensual: somebody gave her things she did not realize were drugs and she got high unintentionally. Yet these experiences were emotionally significant enough for her to convince her to pursue drug highs of her own volition. When she has the opportunity to choose freely after running away from home, she chooses drugs.
The Diarist's first sexual experience, which occurs during a LSD trip, was not something to which she consented. However later in the book she consensually prostitutes herself to strangers in exchange for an opportunity to have more drug experiences. This decision, clearly a byproduct of addiction, cannot objectively be considered to be consensual although the Diarist believes that it is.
Irony of Freedom
The Diarist runs away from home in order to join the drug counterculture, because she feels as though ordinary life is a constraint on her freedom. However she uses her newfound freedom to indulge more heavily in drugs, to the point where she becomes addicted: her behavior changes to revolve around her drug use and she finds herself making increasingly self-destructive choices in order to get access to more. Despite the obvious effects on her health and some very negative experiences, the Diarist continues to use a variety of drugs. So instead of achieving freedom, she is shown as effectively enslaving herself to mind altering substances.
Irony of Trust
The Diarist is consistently and sometimes systematically betrayed by people she meets and trusts. She is first given drugs by friends at a party. She and one of her female friends "date" older college-aged boys only to be used by them to sell drugs so as to make money for the boys. She is even raped by someone who introduces her to heroin. Yet she continues to trust people from the drug scene instead of her parents, doctors, and other people who show themselves worthy of her trust. Although there are people in her life who are trustworthy, who love her unconditionally and who deserve her trust, the Diarist rejects them in favor of people who exploit and harm her.
Irony of Sobriety
The Diarist, after experiencing homelessness and returning to her family with the help of a priest, is determined to stay away from drugs. Yet her friends from the drug scene are unwilling to accept her new sobriety. Her decision to reject drug use alienates her from her chosen peers. They eventually drug her against her will which results in a "bad trip" and confinement to a psychiatric hospital.
Irony of Recovery
The Diarist, after leaving the psychiatric hospital, is supposedly free of drugs. She stops using the diary, having developed what is supposed to be a healthy life with friends, a nice boyfriend, and a positive approach to school. But three weeks after the final entry she is found dead of a drug overdose.
