title: Comparing cannabis with tobacco: those who start taking cannabis young have the greatest problems.
authors.forename: C Heather
authors.initials: CH
authors.lastname: Ashton
mesh_terms: D000367:Age Factors; D006801:Humans; D008385:Marijuana Smoking / Q000009:adverse effects*; D001523:Mental Disorders / Q000209:etiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects