Our study was motivated by epidemiological and clinical data supporting nosological distinctions between FTND-defined and ICD- or DSM-based diagnoses, including some studies that suggest qualitative and quantitative differences in the associations between DSM- and FTND-defined nicotine dependence and some psychopathology (Breslau & Johnson, 2000; Brook, Koppel, & Pahl, 2009). The FTND is brief and, therefore, easily and frequently collected. It has been especially prioritized in clinical trials of tobacco cessation (Ramon, Morchon, Baena, & Masuet-Aumatell, 2014; Tashkin et al., 2011), likely because FTND scores correlate well with relapse and treatment response, and the scale places a great deal of emphasis on physiological aspects of dependence (e.g. items related to tolerance and withdrawal [Baker, Breslau, Covey, & Shiffman, 2012]). On the other hand, both ICD- and DSM-based nicotine dependence include criteria related to physical and psychological (and social, in DSM-5) impairment due to nicotine/tobacco use, as well as behaviors directed at seeking and using nicotine to the exclusion of other activities. Neither FTND nor the ICD-TUD diagnostic classification maps perfectly to DSM-NicDep (Moolchan et al., 2002; Mwenifumbo & Tyndale, 2011).
