The Nicotine Dependence Syndrome Scale: A multidimensional measure of nicotine dependence

We report the development of a new multidimensional questionnaire to measure nicotine dependence, based on Edwards's syndromal conceptualization of dependence. We present three studies. In study 1, we administered the Nicotine Dependence Syndrome Scale (NDSS) to 317 smokers in a smoking cessation study. Factor analysis of the NDSS revealed five factors: Drive (craving and withdrawal, and subjective compulsion to smoke), priority (preference for smoking over other reinforcers), tolerance (reduced sensitivity to the effects of smoking), continuity (regularity of smoking rate), and stereotypy (invariance of smoking). A single overall score based on the first principal component, NDSS-T, was retained as a single core measure of dependence. The NDSS showed promising psychometric properties: NDSS-T and factor scores showed strong associations with dependence-relevant measures, even when we controlled for scores on the Fagerstr6m Tolerance Questionnaire (FTQ); and the NDSS predicted urges when smoking, withdrawal in acute abstinence, and outcome in cessation. The five factor scores showed differential patterns of correlations with external validators, supporting the multidimensionality of the measure. In study 2, we revised the NDSS to expand some subscales and administered it to 802 smokers in a cessation study. The same five factors were extracted, the internal reliability of some subscales was improved, and the factor scores again showed associations with dependence-relevant validators, which were largely maintained when we controlled for FTQ scores. In study 3, with 91 smokers in a cessation trial, we established that the test-retest reliability of the subscales was adequate. Thus, the NDSS presents a valid multidimensional assessment of nicotine dependence that may expand on current measures.