Table 3.

Parameter estimates and 95 % confidence intervals (CIs) for the results of the best-fitting (and selected second best-fitting) bivariate twin models for symptoms of disordered gambling (DG) and substance use and depression

Phenotype	Best-fit model	Parameter (estimate) and 95 % confidence interval (lower, upper)
			Phenotype			Pathological gambling			Correlation
			a	c	e	a	c	e	r a	r c	r e
Major depression	AE	Estimate	0.56	—	0.44	0.83	—	0.17	0.14	—	0.31
		Lower CI	0.45	—	0.32	0.74	—	0.14	–0.04	—	–0.01
		Upper CI	0.67	—	0.55	0.88	—	0.26	0.30	—	0.58
Alcohol consumption	ACE	Estimate	0.29	0.53	0.18	0.69	0.14	0.17	0.41	1.00	0.20
		Lower CI	0.14	0.48	0.17	0.44	0.03	0.10	0.07	0.55	–0.04
		Upper CI	0.38	0.66	0.24	0.83	0.37	0.24	0.73	1.00	0.43
Alcohol consumption	ACE-AEa	Estimate	0.37	0.44	0.19	0.83	—	0.17	0.80	—	0.07
		Lower CI	0.22	0.29	0.15	0.74	—	0.12	0.61	—	–0.17
		Upper CI	0.53	0.56	0.24	0.88	—	0.26	1.00	—	0.29
Caffeine consumption	ACE-AE	Estimate	0.31	0.26	0.43	0.83	—	0.17	0.38	—	–0.09
		Lower CI	0.11	0.08	0.36	0.74	—	0.12	0.17	—	–0.30
		Upper CI	0.53	0.42	0.50	0.88	—	0.27	0.72	—	0.14
Cigarette use	AE	Estimate	0.88	—	0.12	0.81	—	0.19	0.55	—	–0.06
		Lower CI	0.81	—	0.08	0.72	—	0.13	0.43	—	–0.41
		Upper CI	0.52	—	0.18	0.88	—	0.28	0.67	—	0.31
Nicotine dependence	ACE	Estimate	0.46	0.36	0.18	0.64	0.18	0.18	0.29	1.00	0.29
		Lower CI	0.16	0.08	0.12	0.37	0.01	0.12	–0.16	0.45	–0.10
		Upper CI	0.76	0.59	0.29	0.83	0.41	0.29	0.63	1.00	0.61
Nicotine dependence	ACE-AEa	Estimate	0.64	0.18	0.18	0.81	—	0.19	0.57	—	0.19
		Lower CI	0.32	0b	0.12	0.72	—	0.12	0.40	—	–0.19
		Upper CI	0.88	0.43	0.28	0.88	—	0.28	0.86	—	0.55

a, Additive genetic effects; c, shared environmental effects; e, individual-specific environmental effects; r_a, additive genetic correlation; r_c, shared environmental correlation; r_e, individual-specific environmental correlation.

^aSecond best-fit model included for comparison.

^bActual 95 % CI for path was −0.66 to +0.66.