| - BACKGROUND: International reseach implies that adolescents' substance use is determined by the prototypes they hold about peers who use substances. These prototypes can be defined as the whole scale of positive and negative evaluations of substance-using peers. Despite these promising international research findings, the role of prototypes in predicting substance use has not been studied in the Netherlands until recently. In 2001, the IVO started a cross-sectional study on the association between smoker and drinker prototypes and actual smoking and drinking among adolescents. The present research will be a continuation of this first Dutch study. The aim of the present research is twofold: to gather longitudinal data on smoking and drinking among the same sample of adolescents engaging in the ongoing study, and to test the effectiveness of a prototype intervention in preventing smoking onset. Thus, the latter will not address drinking. - HYPOTHESES: The following hypotheses will be studied among adolescents aged 13-15 years: (1) prototypes of smokers and drinkers determine the onset of smoking and drinking, (2) a minimal intervention aiming at the modification of smoker and non-smoker prototypes will be effective in changing smoking intentions and preventing smoking onset, and (3) presenting an unfavourable image of smoking peers will be more effective in changing smoking intentions and preventing smoking onset than presenting a favourable image of non-smoking peers. - METHOD: In the ongoing study, a self-report questionnaire was distributed among 3200 adolescents aged 12-14 of all school levels. In the present research, the same questionnaire will be administered among the same sample of adolescents (now aged 13-15 years) 12 months later. This longitudinal measurement will allow us to draw conclusions on the causal role of smoker prototypes in determining smoking onset. In addition, an experimental study will be carried out among 900 adolescents, testing the impact of two prototype interventions - one presenting an unfavourable image of smoking peers and one presenting a favourable image of non-smoking peers - on smoking intentions and actual smoking behaviour. The proposed research will yield more insight into the potential value of prototypes for primary prevention of substance use among adolescents. Such information is necessary in order to be able to enhance the effectiveness of current programs aiming at the prevention of substance use among adolescents. - OBJECTIVES: The present research project is aimed at the prevention (or delay) of smoking and drinking onset among adolescents aged 13-15 years. The primary objective of the longitudinal study is to obtain more insight into the following issues among adolescents aged 13-15 years: (1) Which factors contribute to the development of positive or negative prototypes of smoking and drinking peers? (2) To what extent do prototypes of smoking and drinking peers contribute to the onset of smoking and drinking? (3) Which factors moderate the causal relationship between prototypes and the onset of smoking and drinking? (4) What is the surplus value of smoker and drinker prototypes in predicting smoking and drinking, in addition to other relevant determinants of smoking and drinking onset? - OBJECTIVES: The primary objective of the experimental study is to gain more insight into the following questions: (5) To what extent is a minimal intervention aiming at the modification of smoker and non-smoker prototypes effective in changing smoking intentions and preventing smoking onset? (6) Which prototype frame - a negatively framed smoker prototype or a positively framed non-smoker prototype - will be more effective in changing smoking intentions and preventing smoking onset? The secondary objective of the present research is to contribute to enhancing the effectiveness of current programs aiming at the prevention of substance use among adolescents. - RELEVANCE FOR CARDIOVASCULAR DISEASES: Cigarette smoking is the largest preventable cause of cardiovascular disease. In addition, excessive alcohol use is regarded a risk factor for cardiovascular disease. Because both smoking cessation and reduction in excessive alcohol use are hard to achieve, public health efforts have emphasised the importance of preventing the initial onset of smoking and excessive drinking. |
