Which substance is most dangerous? Perceived harm ratings among students in urban and rural Norway.

BACKGROUND Recent studies have challenged the idea that illegal substances are necessarily associated with more harm than those that are legal. This study investigates perceived drug harm among students at the University of Oslo (UO) and at a smaller university located on Norway's coast in a more conservative and religious region, called 'Coastal University' (CU). METHODS This study consisted of surveys (n=458) about perceived physical harm, mental health conditions, dependence, injuries and social consequences that may be associated with the use of tobacco, alcohol and cannabis. Information about substance use was also collected. Analyses of variance and multiple regression analyses were used to examine whether harm ratings differed for different drugs, whether drug type, gender and university site interacted in predicting harm ratings, and what role the participants' own substance use played in their harm ratings. RESULTS UO students rated cannabis as overall less harmful than alcohol, while the opposite was true for CU students. Tobacco received the highest physical harm score. Alcohol was rated as most harmful with regard to injuries; cannabis was rated as most harmful with regard to mental health consequences. Use of the substance in question was associated with a reduced harm rating. This was particularly true for cannabis. CONCLUSIONS Norwegian students rate the harm of substances differently from previous reports from the Norwegian general population. Most importantly, their relative ratings of cannabis harm were lower. However, the pattern was most evident among students from the urban Oslo area.