The European Journal of Public Health Advance Access published online on October 5, 2009
The European Journal of Public Health, doi:10.1093/eurpub/ckp148
Influence of cannabis use trajectories, grade repetition and family background on the school-dropout rate at the age of 17 years in France
Stéphane Legleye1,2, Ivana Obradovic1, Eric Janssen1, Stanislas Spilka1, Olivier Le Nézet1 and François Beck3,4
1 French Monitoring Centre for Drugs and Drug Addiction – Observatoire Français des Drogues et des Toxicomanies (OFDT)
2 Inserm U669, Paris XI University, Paris, France
3 National Institute for Prevention and Health Education (INPES), Saint-Denis, France
4 Cesames, Centre de Recherche Psychotropes, Santé mentale, Société (CNRS UMR 8136, Inserm U611, René Descartes Paris V University, Paris, France)
Correspondence: Stéphane Legleye, OFDT: 3 avenue du stade de France, 93218 Saint-Denis la Plaine, France, tel: +33 1 41 62 77 37, fax: +33 1 41 62 77 00, e-mail: stleg{at}ofdt.fr
Received February 18, 2009 , accepted August 27, 2009
Background: Research has shown that cannabis use contributes to school dropout, but few studies have distinguished the age at onset of use from the age at progression to daily use neither their interaction with grade repetition. Methods: This study is based on a French representative cross-sectional survey (N = 29 393 teenagers aged 17 years) and uses retrospective data. The influence of drug-use patterns <16 years of age on school-dropout rates (5.3%) are modelled with logistic regressions among boys and girls. Results: The main factors associated with dropout were a low family socio-economic status, early grade repetition, single-parent families and daily tobacco smoking (ORa 
2.6). The link with the move to daily cannabis use was more evident when it occurred <14 years of age (ORa = 2.05 for boys and 3.41 for girls) rather than at 15 years (ORa = 1.45 for both sexes). The onset of cannabis use was not significant when occurring <14 years of age, but was linked to school attainment when occurring at age 15–16 years (ORa = 0.80 for boys and 0.64 for girls). Results are similar for alcohol use. Repeating a grade before beginning to use cannabis increased the dropout rates compared with the opposite sequence. Girls were more affected by early grade repetition and by early and daily cannabis use. Conclusion: Cannabis use is rarely a trigger for grade repetition but can have either damaging or positive effects on school attainment depending of the level of use. Positive social competence reflected by peer initiation should be investigated to understand this paradoxical effect.
Keywords: cannabis, drug use, France, gender, school dropout.