title: Self-control and its relation to joint developmental trajectories of cannabis use and depressive mood symptoms.
abstract: BACKGROUND
  Cannabis use and depressive mood symptoms in adolescence have been found to co-occur. In exploring the nature of this relationship and in the search for mechanisms that explain this link, scholars have postulated the idea for a 'common liability model'. According to this model, the link between cannabis use and depressive symptoms can be explained by an underlying risk factor. One important candidate for this underlying risk factor may be self-control, as a reflection of immature self-regulatory systems in adolescence. In the present study, we will test the extent to which joint development of cannabis use and depressive symptoms can be explained as an expression of self-control.
  
  
  METHODS
  A total of 428 adolescents participated in a five-wave longitudinal design. Main study outcomes were self-reports of self-control (age 12) and cannabis use and depressive symptoms (ages 12-16).
  
  
  RESULTS
  We established six trajectories of joint development of cannabis use and depressive symptoms. Conditional probabilities indicated that cannabis use and depressive symptoms were symmetrically related. Levels of self-control were lowest for adolescents following the joint developmental pathway of cannabis use and high depressive symptoms.
  
  
  CONCLUSIONS
  Low levels of self-control are predictive of joint development of cannabis use and depressive symptoms. Future studies should concentrate on the role of self-control in co-occurrence of other health risk behaviors and on psychological and physiological mechanisms underlying self-control and its relation to co-occurrence.
authors.affiliation: Behavioural Science Institute, Radboud University, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands. r.otten@pwo.ru.nl
authors.forename: Roy
authors.initials: R
authors.lastname: Otten
authors.forename: Edward D
authors.initials: ED
authors.lastname: Barker
authors.forename: Barbara
authors.initials: B
authors.lastname: Maughan
authors.forename: Louise
authors.initials: L
authors.lastname: Arseneault
authors.forename: Rutger C M E
authors.initials: RC
authors.lastname: Engels
mesh_terms: D000293:Adolescent; D000339:Affect / Q000187:drug effects*; D002188:Cannabis; D003863:Depression / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006801:Humans; D007389:Internal-External Control; D008297:Male; D008385:Marijuana Smoking / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012649:Self Concept; D012737:Sex Factors; D011795:Surveys and Questionnaires