Table 2.

Smoking trajectories regressed on ADHD symptoms, rs13280604/rs892413, and their interaction terms.

	Non-use vs. use						Number of smoked
	Intercept		Slope		Quad		Intercept		Slope		Quad
Model	Est.	SE	Est.	SE	Est.	SE	Est.	SE	Est.	SE	Est.	SE
# 1
Intercept	NA		0.77	6.63	−1.52	3.36	−0.69	1.14	2.16	2.40	−0.70	1.20
HI	−0.10	0.22	0.34	0.74	−0.23	0.39	−0.07	0.07	0.48**	0.15	−0.27***	0.07
IN	0.02	0.18	−0.43	0.73	0.25	0.39	0.11	0.06	−0.40**	0.15	0.22**	0.07
AA	1.48	1.39	−3.16	4.41	1.89	2.09	−0.75	0.39	0.61	0.82	−0.39	0.33
AG	2.06	1.75	−4.31	4.49	2.36	2.02	0.06	0.42	−0.05	0.96	−0.03	0.45
# 2
Intercept	NA		−0.97	6.69	−1.03	3.26	−1.36	1.25	2.03*	2.25	−0.54	1.03
AA * HI	0.24	0.49	−0.33	1.42	−0.50	0.74	0.51*	0.20	−0.73*	0.37	0.36*	0.18
AG * HI	0.76	0.50	−1.93	1.61	0.45	0.87	0.47*	0.19	−0.56	0.35	0.27	0.18
AA * IN	−1.36*	0.62	3.86*	1.95	−1.29	0.99	−0.58**	0.20	1.34**	0.51	−0.56*	0.23
AG * IN	−1.80**	0.68	5.26**	2.03	−2.20*	1.06	−0.59**	0.16	1.30**	0.47	−0.54*	0.24
# 3
Intercept	NA		−4.75	5.14	1.74	2.70	−1.90	1.46	2.92	2.21	−0.99	1.12
HI	−0.10	0.19	−0.07	0.53	−0.06	0.29	−0.10	0.08	0.50**	0.17	−0.28***	0.07
IN	−0.06	0.13	−0.00	0.49	0.05	0.29	0.25***	0.05	−0.32**	0.11	0.15**	0.05
AA	−0.03	0.78	3.21	3.52	−1.98	1.82	−1.12***	0.29	1.24	0.68	−0.79*	0.32
AC	−0.54	0.82	4.84	3.17	−2.67	1.63	−0.07	0.34	0.72	0.72	−0.51	0.39
# 4
Intercept	NA		−6.95	4.65	2.80*	2.51	−0.88*	1.32	2.36	2.25	−0.78	1.11
AA * HI	−1.45	1.10	4.94	3.51	−2.45	1.81	0.18	0.18	0.26	0.38	−0.08	0.20
AC * HI	−0.10	1.18	1.17	3.59	−0.52	1.86	0.12	0.16	0.29	0.41	0.07	0.24
AA * IN	0.72	0.67	−3.17	2.09	1.70	1.10	−0.18	0.32	−0.24	0.53	0.05	0.20
AC * IN	−0.20	0.79	−0.38	2.27	0.14	1.21	−0.41	0.27	−0.14	0.44	−0.06	0.17

Note. Models 1 and 2 were results for SNP rs13280604 and comparison group was GG variant (n = 871) whereas Models 3 and 4 (n = 935) were for SNP rs892413 and the comparison group was CC variant. HI = Hyperactive–Impulsive symptoms. IN = Inattentive symptoms.

^*p < .05.

^**p < .01.

^***p < .001.