Table 1.

Demographic, clinical, personality, and neurobehavioral characteristics of participants

	HC (N=81)		Heroin (N=44)		Amphetamine (N=39)		Poly (N=58)		Test statistic (F)	Sig.	Post- hoc
	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Demographic
Age	24.27	4.42	29.32	4.86	23.44	4.04	25.95	4.86	15.03	6.31E- 09	a,d,e,f
Gender (%Male)	72.84		75.00		66.67		84.48		4.45	n.s.
Education (yrs)	13.80	2.27	12.61	2.36	13.10	2.36	12.83	1.87	3.62	0.014	a,c
IQ	109.94	12.85	102.50	13.35	110.85	10.78	105.84	13.21	4.49	0.004	a,d
# of relatives with alcohol/drug problems	0.42	0.79	0.66	0.86	0.54	0.68	0.86	0.83	3.63	0.014	c
Psychiatric
History of Conduct Disorder (%)	12.34		36.36		41.03		62.07		37.54	3.53E- 08	a,b,c,e
History of ASPD (%)	6.17		34.09		35.90		58.62		44.95	9.50E- 10	a,b,c,e
Yrs of Heroin use	0.00	0.00	7.10	3.08	0.00	0.00	3.89	4.97	71.39	2.00E- 16	a,c,d,e,f
Yrs of Amphetamine use	0.69	2.42	0.16	0.94	3.98	2.42	2.90	2.98	26.25	2.01E- 14	b,c,d,e
Yrs of Alcohol use DSM-IV Past dependence	8.53	4.75	10.90	5.53	7.85	4.04	10.07	5.23	3.55	0.015	d
Alcohol (%)	0.00		0.00		0.00		22.41		44.43	1.22E- 09	c,e,f
Sedatives (%)	0.00		0.00		0.00		6.90		12.23	0.007
Cannabis (%)	0.00		0.00		0.00		82.76		150.36	2.20E- 16	c,e,f
Amphetamine (%)	0.00		0.00		100.00		67.24		156.23	2.20E- 16	b,c,d,e,f
Opiates (%)	0.00		100.00		0.00		44.83		155.66	2.20E- 16	a,c,d,e,f
Cocaine (%)	0.00		0.00		0.00		6.90		12.87	0.005
Hallucinogens (%)	0.00		0.00		0.00		6.90		12.87	0.005
Length of Abstinence(yrs)	1.09	2.28	1.74	2.35	0.40	0.60	0.77	0.96	4.2	0.007	d,e
Fagerstrom Test of nicotine dependence	1.41	2.10	4.27	2.71	2.62	2.41	4.57	2.97	22.2	1,39E- 12	a,c,d,f
Psychopathy Checklist (PCL:SV) Factor 1	2.12	2.10	4.73	2.58	3.13	2.58	4.88	2.68	18.71	7.78E- 11	a,c,d,f
Psychopathy Checklist (PCL:SV) Factor 2	2.57	2.44	7.16	2.82	5.00	2.76	7.67	2.65	52.23	2.00E- 16	a,b,c,d,f
Wender Utah Rating Scale (WURS) for ADHD	21.90	11.58	30.98	16.20	26.28	13.51	32.10	15.40	7.41	9.53E- 05	a,c
Depression (BDI-II)	5.67	5.70	8.61	5.75	6.54	4.89	8.84	7.72	3.95	0.009	c
Stait Anxiety	31.86	7.12	36.32	8.51	32.15	6.57	35.76	8.28	5.20	0.002	a,c
Trait Anxiety	36.30	8.42	40.25	9.53	38.87	9.31	42.29	10.01	5.04	0.002	c
Anxiety Sensitivity	15.23	7.22	17.27	9.02	17.62	8.87	19.69	9.49	3.13	0.027	c
Personality
Levenson’s Self-Report Psychopathy Scale	35.52	8.67	37.70	9.95	37.87	6.87	39.78	7.37	3.00	0.032	c
BIS Nonplanning	22.48	4.97	26.00	4.77	24.79	4.97	25.00	4.71	6.09	5.38E- 04	a,c
BIS Motor	21.35	4.04	23.34	5.76	24.79	4.41	24.10	4.80	6.41	3.50E- 04	b,c
BIS Attention	14.86	3.35	15.36	3.89	16.74	3.70	16.43	3.81	3.39	0.019	b
Buss-Warren Physical	15.47	5.52	18.70	6.59	18.97	6.09	20.91	6.36	9.65	5.21E- 06	a,b,c
Buss-Warren Verbal	14.67	3.75	15.09	3.21	15.51	3.46	15.67	3.37	1.09	n.s.
Buss-Warren Anger	15.00	3.69	16.91	3.92	16.46	3.15	17.64	4.32	5.87	7.12E- 04	a,c
Buss-Warren Hostility	15.04	5.10	16.52	4.65	18.05	6.25	18.21	5.46	5.03	0.002	b,c
Buss-Warren Indirect	13.17	4.44	15.23	4.45	14.44	3.89	16.09	4.23	5.63	0.001	c
UPPS Urgency	21.93	6.07	27.50	6.28	24.97	5.86	28.10	6.75	13.54	3.91E- 08	a,c
UPPS Lack of Premeditation	24.14	5.58	26.14	6.00	26.10	5.46	26.90	6.18	2.90	0.036	a
UPPS Lack of Perseverance	19.07	4.76	21.20	4.74	20.59	5.70	21.26	5.28	2.78	0.042
UPPS Sensation Seeking	27.21	7.04	27.00	8.23	30.33	7.93	29.84	6.90	2.84	0.039
SSS: Disinhibition	4.33	2.50	4.66	2.84	6.08	2.16	5.78	2.22	6.66	2.53E- 04	b,c,d
SSS: Boredom Susceptibility	3.22	1.87	3.70	2.15	4.26	2.21	4.03	2.06	2.97	0.033	b
SSS: Thrill and Adventure Seeking	6.15	3.08	5.73	3.03	7.00	2.89	7.43	2.11	4.03	0.008	c,e
SSS: Experience Seeking	5.37	2.00	5.34	2.07	6.49	1.59	6.34	1.83	5.5	0.001	b,c,d,e
Neurobehavioral
IGT: ABCD	4.86	26.37	−0.59	25.98	2.64	28.04	3.02	25.94	0.41	n.s.
IGT: EFGH	18.51	38.94	10.93	32.54	11.18	37.76	20.24	36.86	0.87	n.s.
SST %inhibition, 50ms	93.02	9.70	94.77	6.73	92.05	9.23	88.97	14.01	2.90	0.036	e
SST %inhibition, 150ms	76.67	18.17	76.14	13.46	72.44	20.68	74.57	19.27	0.54	n.s.
SST %inhibition, 250ms	52.53	20.83	50.34	15.94	52.31	24.06	47.59	23.49	0.69	n.s.
SST %inhibition, 350ms	30.37	18.60	25.80	12.80	33.33	17.07	31.72	20.87	1.41	n.s.
IMT d′	1.22	0.50	1.03	0.46	1.17	0.43	1.04	0.58	2.18	n.s.
IMT b	0.80	0.30	0.83	0.35	0.76	0.29	0.84	0.34	0.58	n.s.
IMT Commission Error (%)	36.19	13.24	38.95	13.10	38.75	11.50	38.62	14.91	0.64	n.s.
IMT Omission Error (%)	22.32	12.31	26.38	15.63	20.89	10.97	26.29	15.53	2.05	n.s.
Delay discounting rate (log(k))	−3.11	1.20	−2.88	1.01	−2.45	0.86	−2.91	0.94	3.51	0.016	b
BART pumps	40.14	10.07	39.92	13.43	40.88	13.86	40.65	15.04	0.06	n.s.
Go/Nogo False Positives	14.49	8.15	16.55	8.44	16.74	6.57	18.17	10.09	2.19	0.090
Go/Nogo False Negatives	16.10	18.19	18.93	15.45	17.15	13.34	18.02	16.60	0.32	n.s.
Go/Nogo d′	2.30	0.77	2.07	0.83	2.06	0.64	2.01	0.78	2.02	n.s.
Go/Nogo b	0.54	0.43	0.61	0.60	0.49	0.29	0.56	0.48	0.47	n.s.
CGT Delay Aversion	0.32	0.19	0.42	0.22	0.31	0.16	0.34	0.20	3.29	0.022	a,d
CGT Decision Time (msec)	2314.61	650.45	2269.23	707.88	2510.87	714.98	2415.23	748.75	1.08	n.s.
CGT Quality Decision Making	0.87	0.14	0.85	0.17	0.87	0.12	0.87	0.12	0.39	n.s.
CGT Risk Aversion	0.99	0.86	0.91	0.91	1.03	0.89	0.71	0.66	1.63	n.s.
CGT Risk Taking	0.63	0.12	0.60	0.13	0.62	0.13	0.64	0.13	0.55	n.s.

Note. ASPD = Antisocial Personality Disorder; BDI = Beck Depression Inventory; BIS = Barratt Impulsiveness Scale; SSS = Sensation-Seeking Scale; IGT = Iowa Gambling Task; SST = Stop Signal Task; IMT = Immediate Memory Task; CGT = Cambridge Gambling Task; n.s = non-significant (p > 0.10).

^aHC vs. Heroin groups is significantly different.

^bHC vs. Amphetamine groups is significantly different.

^cHC vs. Poly-substance groups is significantly different.

^dHeroin vs. Amphetamine groups is significantly different.

^eHeroin vs. Poly-substance groups is significantly different.

^fAmphetamine vs. Poly-substance groups is significantly different.