In this study, we also found modest multipoint elevations for DSM-IV NW on chromosomes 6 (for the Finnish sample) and 7 (after combining the samples). While Swan et al.’s (2006) linkage peak for nicotine withdrawal was also located on chromosome 6 at 159 cM (near the OPRM1) this was far from our location at 75 cM. The two studies used rather different phenotypic definitions. Perhaps most notably, in this study we used a diagnostic definition of nicotine withdrawal, while Swan et al. (2006) used a quantitative measure of withdrawal severity.
