The drug use patterns and behaviours of 90 young people who reported cannabis use from the age of 11/12 years when they entered post primary schooling and continued to report its use during three further annual data waves of the Belfast Youth Development Study (a longitudinal study of the onset and development of adolescent drug use) until the age of 15 are examined in this paper. The data collected from these young people revealed high levels of both licit and illicit drug use compared with young people who have not used cannabis by the age of 15.

The findings suggest the existence of a 'hidden' high risk group of young people who continue to attend school regularly. This raises the question about the extent to which their needs are being met by existing school based drugs education and prevention initiatives which are often delivered through a standardised strategy for all school aged young people