Table 1.

Nicotine Dependence Syndrome Scale (NDSS) factor structure (N=1160 smokers)

				3-factor solution
Questionnaire item		Mean	(SD)	Drive/Priority	Stereotypy/Continuity	Tolerance	Single factor solution
1 (1)	After not smoking for a while, I need to smoke to relive feelings of restlessness and irritability	2.35	(1.23)	0.68	0.32		0.75
2 (2)	Whenever I go without a smoke for few hours, I experience craving.	2.87	(1.33)	0.58	0.51	0.32	0.83
3 (3)	After not smoking for a while, I need to smoke in order to keep myself from experiencing any discomfort.	2.07	(1.17)	0.72			0.75
4 (4)	When I’m really craving a cigarette, it feels like I’m in the grip of some unknown force that I cannot control.	2.05	(1.23)	0.65			0.63
5 (5)	I feel a sense of control over my smoking. I can “take or leave it” at any time.	2.19	(1.38)	−0.40			−0.55
6 (6)	I tend to avoid restaurants that don’t allow smoking, even if I would otherwise enjoy the food.	1.71	(1.13)	0.50			0.47
7 (7)	Sometimes, I decline offers to visit with my non-smoking friends because I know I’ll feel uncomfortable if I smoke.	1.28	(0.71)	0.43
8 (8)	Even if travelling a long distance, I’d rather not travel by airplane because I wouldn’t be allowed to smoke.	1.48	(0.93)	0.50			0.45
9 (9)	Since the time when I became a regular smoker, the amount I smoke has either stayed the same or has decreased somewhat.	2.48	(1.32)			−0.44
10 (10)	Compared to when I first started smoking, I need to smoke a lot more now in order to get what I really want out of it.	2.00	(1.21)	0.42		0.63	0.68
11 (11)	Compared to when I first started to smoking, I can smoke much, much more now before I start to feel nauseated or ill.	2.69	(1.43)	0.32		0.68	0.67
12 (12)	It’s hard to estimate how many cigarettes I smoke per day because the number often changes.	2.23	(1.18)
13 (15)	I smoke at different rates in different situations.	3.06	(1.25)			0.33
14 (16)	My smoking is not much affected by other things. I smoke about the same amount whether I’m relaxed or working, happy or sad, alone or with others, etc.	2.84	(1.18)		0.43
15 (17)	My cigarette smoking is fairly regular throughout the day.	2.95	(1.33)	0.36	0.74		0.76
16 (18)	I smoke consistently and regularly throughout the day.	3.01	(1.51)	0.37	0.61	0.43	0.78
17 (19)	I smoke about the same amount on weekends as on weekdays.	2.90	(1.28)		0.66		0.49
18 (20)	I smoke just about the same number of cigarettes from day to day.	3.03	(1.27)		0.74		0.53
19 (21)	Not even a torrential rainstorm could stop me – if I were out of cigarettes, I would be immediately on my way to the store to get some more.	2.29	(1.38)	0.61	0.32		0.73
20 (22)	Sometimes without realizing it, I go for several hours or more without smoking.	2.96	(1.36)	−0.33			−0.42
21 (23)	Where regulations require that I go outdoors to smoke, it’s worth it to be able to smoke a cigarette, even in cold or rainy weather.	2.72	(1.35)	0.45	0.43	0.38	0.73
22 (24)	I rarely go for very long without smoking.	2.73	(1.30)	0.49	0.53	0.38	0.80
23 (25)	If I wake up during the night, I feel I need a cigarette.	1.51	(1.00)	0.51			0.55
24 (26)	I can function much better in the morning after I’ve had a cigarette.	2.26	(1.34)	0.62	0.36		0.76
25 (27)	Sometimes even when I’m telling myself I’m not going to have a cigarette, I find myself smoking anyway.	2.52	(1.30)	0.50			0.62
26 (28)	Whenever I quit or cut down on smoking, it is an unpleasant experience.	2.22	(1.25)	0.51	0.30		0.62
27 (29)	The last time I quit (for 24 hours or more), when I went back to smoking it took a LONG time for me to build up to my old level of smoking.	1.92	(1.12)
28 (−)	Since I started smoking, I have increased how much I smoke.	2.63	(1.52)			0.68	0.60
29 (−)	I don’t ever crave cigarettes.	1.68	(1.09)	−0.33			−0.44
30 (−)	I can smoke more than I used to before it affects me.	2.11	(1.21)	0.37		0.59	0.64
31 (−)	When I smoke a cigarette I get less of an effect (good or bad) than when I first started.	2.62	(1.26)			0.38	0.36
Coefficient alpha (calculated by loadings above 0.40, except Single factor solution calculated with all 31 items)				0.92	0.88	0.83	0.92

Factor loadings above 0.5 are shown in bold. Factor loadings of 0.25 or less are not shown.

Item numbers in parenthesis are same as in Shiffman et al. (2004) in Table 6, page 340.