title: [Cannabis consumption among secondary school pupils of Barcelona (Spain): initial use, reported effects and expectancies].
abstract: OBJECTIVE
  To describe the circumstances of initial use of Cannabis, as well as the reasons for consumption, reported effects and expectations related to cannabis use, among adolescents in Barcelona.
  
  
  METHODS
  A cross-sectional survey was conducted in a sample of pupils in the third year of compulsory secondary education in 2005. The questionnaire was confidential and self-completed. Data were gathered from 2,043 secondary school pupils from 47 schools in Barcelona.
  
  
  RESULTS
  A total of 37.5% of students reported cannabis consumption at some time, and 10.0% of these students had used cannabis in the previous month. Cannabis use was more common in public schools than in subsidized or private schools (p < 0.001). More than half the adolescents (60.3%) smoked cannabis for the first time in parks or on the street. Most (88.4%) of the adolescents obtained cannabis from a classmate or friend and 92.3% did so without paying for it. The main reason for initial consumption was curiosity, and reasons for continuing use were a desire to feel better and to forget problems. The most frequently reported effects were memory loss, sadness and difficulties in studying or working. Cannabis use was positively related to the expectation that the drug induces relaxation and aids social and sexual relations, and negatively to the beliefs that the drug can impair intellect and behavior and has negative effects on health.
  
  
  CONCLUSIONS
  Cannabis was easily accessible to secondary school pupils and 9 out of 10 obtained the drug from a classmate or friend without paying for it. Two out of 3 adolescents reported negative effects as a consequence of cannabis use. Knowledge of expectations could help to explain and prevent cannabis consumption during adolescence.
authors.affiliation: Servicio de Evaluación y Métodos de Intervención, Agencia de Salud Pública de Barcelona, España.
authors.forename: Eva
authors.initials: E
authors.lastname: Morales
authors.forename: Carles
authors.initials: C
authors.lastname: Ariza
authors.forename: Manel
authors.initials: M
authors.lastname: Nebot
authors.forename: Anna
authors.initials: A
authors.lastname: Pérez
authors.forename: Francesca
authors.initials: F
authors.lastname: Sánchez