Association of withdrawal features with nicotine dependence as measured by the Fagerström Test for Nicotine Dependence (FTND).

The aim of this study was to advance our understanding of how nicotine dependence level, defined by the Fagerström Test of Nicotine Dependence (FTND), relates to nicotine withdrawal features. We classified nicotine dependence in two categories, 1) low dependence (LD; FTND<4) and 2) high dependence (HD; FTND> or =4). A sample of 241 smokers was recruited via newspaper ads and public notices. Using a multivariate response model with adjustments for age, sex, age at first cigarette, race, and current or lifetime depression, we observed a small to modest statistically robust association between nicotine dependence level and withdrawal features such as, irritation/anger (adjusted relative risk, aRR=1.2; 95% CI 1.0, 1.3); nervousness (aRR=1.3; 95% CI 1.1, 1.6); restlessness (aRR=1.2; 95% CI 1.1, 1.4); difficulty concentrating (aRR=1.3; 95% CI 1.1, 1.7); and trouble sleeping (aRR=1.8; 95% CI 1.2, 2.6). Our findings are consistent with the inference that the FTND measures "physiological dependence" and that multidimensional approaches are needed to capture the full range of smoking phenotypology.