Evidence of validity of an inhalant-craving questionnaire.

Inhalants are substances widely used as recreational drugs: their addictive potential has been demonstrated by many studies. There is no reported measurable evidence of craving in inhalant users. The main goal of this study was to design and obtain evidence of validity of the score of a questionnaire for the evaluation of inhalant craving (ICQ) in a Mexican population sample. The ICQ is a type of visual analog scale with ten items. Face validity was evaluated by a group of experts in the addiction field. Reviewers considered the completeness, semantics, and sentence structure to guarantee a conceptual representation of the items. The final ICQ was applied to a sample of 520 Mexican high school students, 46% women and 54% men, between 12-19 years of age (M=15.18; SD=1.48), from 7th to 12th grades. The internal consistency of the ICQ showed a Cronbach's Alpha of 0.947. The 10 items were grouped into one single factor, with a factor loading above 0.74 for each of them. ROC analysis breakpoint was located at 18.5 mm with a sensitivity of 0.855 and specificity of 0.753. Thirty-three per cent (n= 172) of the student population evaluated reported the use of inhalants at some point in their lifetimes, with an average of misuse beginning at 13.6 years of age. The ICQ showed adequate psychometric properties, suggesting that the instrument may be considered a useful tool for screening for craving in young inhalant users.