Leeds Dependence Questionnaire: new data from a large sample of clinic attenders

The main aim of this study was to examine psychometric properties of the Leeds Dependence Questionnaire (LDQ) in a different and larger sample from that on which the instrument was developed. Data were taken from routine intake assessments (n=1681) of referrals to two UK addiction treatment services during an 18 month period. Principal components analyses for the total sample and for three substance category subsamples (alcohol, opioids, “other drugs”) each yielded a single, major component on which all LDQ items loaded highly and positively. The LDQ had high internal consistency in the total sample and in the substance category subsamples. In a multiple regression analysis in the total sample, age (younger), gender (male), higher score on the General Health Questionnaire (GHQ) and substance category (opioid or other drugs vs. alcohol) were independent predictors of higher LDQ scores. The LDQ was shown to give a robust and psychometrically sound measurement of a general factor of dependence across a range of psychoactive substances among attenders at addiction treatment services. Norms are presented to enable clinicians to compare levels of alcohol or opioid dependence shown by individual clients presenting for treatment with those obtained from a large sample of clinic attenders.