%0 Journal Article %T The Choice of Screening Instrument Matters: The Case of Problematic Cannabis Use Screening in Spanish Population of Adolescents %A Danica Thanki %A Ant車nia Domingo-Salvany %A Gregorio Barrio Anta %A Amparo S芍nchez Maˋez %A Noelia Llorens Aleixandre %A Josep Maria Suelves %A Begoˋa Brime Beteta %A Juli芍n Vicente %J ISRN Addiction %D 2013 %R 10.1155/2013/723131 %X The aim of this study was to examine the feasibility of problem cannabis use screening instruments administration within wide school surveys, their psychometric properties, overlaps, and relationships with other variables. Students from 7 Spanish regions, aged 14每18, who attended secondary schools were sampled by two-stage cluster sampling (net sample 14,589). Standardized, anonymous questionnaire including DSM-IV cannabis abuse criteria, Cannabis Abuse Screening Test (CAST), and Severity of Dependence Scale (SDS) was self-completed with paper and pencil in the selected classrooms. Data was analysed using classical psychometric theory, bivariate tests, and multinomial logistic regression analysis. Not responding to instruments* items (10.5每12.3%) was associated with reporting less frequent cannabis use. The instruments overlapped partially, with 16.1% of positives being positive on all three. SDS was more likely to identify younger users with lower frequency of use who thought habitual cannabis use posed a considerable problem. CAST positivity was associated with frequent cannabis use and related problems. It is feasible to use short psychometric scales in wide school surveys, but one must carefully choose the screening instrument, as different instruments identify different groups of users. These may correspond to different types of problematic cannabis use; however, measurement bias seems to play a role too. 1. Introduction Cannabis is the most widely used illicit drug worldwide [1]. Spain is currently the country with the highest last month prevalence of cannabis use among those aged 15每24 in Europe, with consistently high figures since 2005 (17.2每18.6%, [2]) and with the highest prevalence of regular (3每39 times within the past 12 months) and heavy (40 times or more within the past 12 months) use according to 2009/2010 HBSC (Health Behaviour in School-Aged Children, [3]) survey of 15-16-year olds [4]. A range of negative effects of regular cannabis use on adolescent health and psychosocial status have been identified, including adverse effects on psychosocial development and mental health (including developing psychotic symptoms), decrease in academic performance (which can lead to academic failure), and other negative outcomes later in life [5每9]. Since 2009, cannabis as a primary drug has overtaken heroin among those requesting drug treatment for the first time in their lives in the European Union. Its mention as a primary drug further increased in 2010 (accounting for more than 100ˋ000 treatment demands). In this year, 76% of reported treatment %U http://www.hindawi.com/journals/isrn.addiction/2013/723131/