Table 4.
Values for smoking characteristics by 5-HTTLPR genotype in ever smokers after excluding subjects with self-reported psychiatric disorders and/or alcohol dependence
| Characteristic | Mean (SD) | P value | |
| S/S+S/L | L/L | ||
| Duration of smoking | 24.8 ± 11.0 | 28.0 ± 13.1 | 0.18 |
| No. of cigarettes smoked daily | 18.0 ± 9.2 | 17.1 ± 8.5 | 0.73 |
| No of pack/years | 22.9 ± 15.0 | 16.1 ± 17.4 | 0.73 |
| Age of proceeding to regular smoking | 20.6 ± 4.3 | 20.5 ± 4.7 | 0.76 |
| FTND score* | 5.1 ± 2.4 | 5.2 ± 2.0 | 0.79 |
| Duration of the longest abstinence in quitting attempts* | 413.9 ± 1482.3 | 265.9 ± 446.4 | 0.29 |
*only current daily smokers were analysed