title: Estimating harmful effects of cannabis and use for policy makers shifting from one mistake to the next?
authors.affiliation: Institute of Clinical Psychology and Psychotherapy, Center of Clinical Epidemiology and Longitudinal Studies, Technische Universitaet Dresden, Dresden, Germany. wittchen@psychologie.tu-dresden.de
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Wittchen
mesh_terms: D015982:Bias; D006801:Humans; D008385:Marijuana Smoking / Q000009:adverse effects / Q000453:epidemiology*; D011050:Policy Making; D011605:Psychoses, Substance-Induced / Q000453:epidemiology*