Introduced initially in relation to drug policy, ‘zero tolerance’ has become a catchphrase to describe attitudes and policies relating to drug use, violence and a range of antisocial behaviours. It has been used particularly within schools in the United States as a disciplinary policy since the 1980s. While broadly ascribed, zero tolerance is designed to send a message that targeted behaviours are not tolerated and will be punished. Zero tolerance assumes that swift and uncompromising action aimed at punishing the offender will result in ‘sending a strong message’ to other would-be offenders and deter others from similar antisocial behaviours. However, thirty years of research has shown zero tolerance policies to have failed the individual and the community, resulting instead in increased rates of misbehaviour and early referral to the juvenile and criminal justice systems. This has the potential to negatively impact on the person's mental health and future outcomes.