The aims of the CLAN survey were to establish a national student profile of lifestyle habits. The survey was undertaken by the Department of Health and Children among undergraduate full-time students during the academic year 2002/2003 in 21 third level colleges in Ireland. The results of the study showed that cannabis was the most common illegal drugs used by students, with 37% reporting that they had used in the past 12 months, and 20% during the past 30 days. Drug use in the student population was much higher than in the 2003 NACD drug prevalence survey. The survey also measured alocohol related harm, such as effects on study and financial probles.