. 2019 Jan 4;21:101652. doi: 10.1016/j.nicl.2019.101652

Table 1.

Demographic data and substance use information.

	Baseline							Follow-up
	Controls (n = 38)	Decreasers (n = 15)	Sustained Users (n = 14)	F/χ²/t	df, df_err	P	Effect size	Controls (n = 38)	Decreasers (n = 15)	Sustained Users (n = 14)	F/χ²/t	df, df_err	P	Effect size
Age (year)	30.0 (6.8)	31.5 (5.5)	32.9 (7.1)	1.08^a	2,64	0.34	_pη² = 0.03
Sex (female/male)	15/23	7/8	2/12	3.81^b	2	0.15	V = 0.24
Hair color (bl/br/blk)^d	0/31/3	0/11/3	0/10/1	1.61^b	2	0.49	V = 0.17
Years between TP1/TP2	1.5 (1.3)	1.8 (1.6)	1.6 (1.5)	0.32^a	2,64	0.73	_pη² = 0.01
Education (year)	10.5 (1.5)	10.7 (1.7)°	9.4 (0.7)^⁎	3.99^a	2,64	0.02	_pη² = 0.11
Verbal IQ (MWT-B)	107.2 (9.8)	104.5 (11.8)	98.2 (9.0)^⁎	4.02^a	2,64	0.02	_pη² = 0.11
ADHD-SR score	6.7 (5.7)	13.8 (8.6)^⁎⁎	18.8 (9.0)^⁎⁎⁎	16.24^a	2,64	<0.001	_pη² = 0.34
BDI score	2.6 (3.0)	8.2 (8.2)^⁎⁎	10.2 (9.5)^⁎⁎⁎	9.74^a	2,64	<0.001	_pη² = 0.23	2.4 (4.7)	5.7 (5.4)	10.5 (11.4)^⁎⁎	7.59^a	2,64	0.001	_pη² = 0.19
Cocaine
Times per week^e	–	2.4 (2.0) n = 14	2.7 (1.9) n = 13	0.44^c	25	0.66	d = 0.17	–	0.6 (0.9)	2.6 (2.2)	3.09^c	27	0.007	d = 1.27
Grams per week^e	–	1.9 (1.4)	5.9 (13.5)	1.15^c	27	0.26	d = 0.54	–	0.7 (1.3)	4.7 (8.8)	1.68^c	27	0.12	d = 0.79
Years of use	–	7.5 (5.6)	8.6 (5.2)	0.56^c	27	0.58	d = 0.21	–	9.0 (6.2)	10.2 (6.2)	0.54^c	27	0.60	d = 0.20
Cumulative dose (g)^f	–	811 (929)	1966 (2125)	1.87^c	27	0.08	d = 0.76	–	80 (90) n = 14	290 (696)	1.12^c	26	0.27	d = 0.53
Maximum dose (g/d)	–	4.5 (3.0)	3.9 (3.5)	0.47^c	27	0.64	d = 0.18	–	2.2 (1.7) n = 10	3.7 (4.6) n = 12	0.94^c	20	0.36	d = 0.46
Last consumption (d)	–	10 (15) n = 14ⁱ	10 (11)	0.11^c	26	0.92	d = 0.04	–	54 (110) n = 13^k	6 (5)	1.57^c	25	0.14	d = 0.84
Cocaine craving	–	30.1 (15.7) n = 14	26.1 (11.8) n = 13	0.76^c	25	0.46	d = 0.30	–	15.5 (6.7)	29.4 (17.2) n = 13	2.75^c	26	0.02	d = 1.17
Hair analysis (ng/mg)^d
Cocaine_total	–	13.3 (15.6)	27.7 (40.6)	1.23^c	23	0.23	d = 0.51	–	4.9 (6.0)	52.2 (37.8)	4.46^c	26	0.001	d = 2.15
Cocaine	–	9.9 (11.1)	21.0 (30.9)	1.25^c	23	0.22	d = 0.53	–	3.7 (4.6)	37.8 (28.4)	4.28^c	26	0.001	d = 2.07
Benzoylecgonine	–	3.1 (4.3)	6.2 (9.2)	1.12^c	23	0.28	d = 0.46	–	1.1 (1.5)	13.5 (11.0)	4.02^c	26	0.002	d = 1.99
Cocaethylene	–	0.6 (1.0)	0.6 (0.6)	0.14^c	23	0.89	d = 0.06	–	0.5 (0.6)	1.5 (1.7)	2.12^c	26	0.05	d = 0.91
Norcocaine	–	0.3 (0.4)	0.5 (0.6)	1.04^c	23	0.31	d = 0.42	–	0.1 (0.1)	0.9 (0.6)	4.59^c	26	<0.001	d = 2.09
Urine toxicology (neg/pos)^g	38/0	8/7	7/7	0.03^b	1	0.86	V = 0.03	38/0	11/4	6/8	2.77^b	1	0.10	V = 0.31
Alcohol
Grams per week^e	77.9 (110.7)	265.0 (598.4)	306.2 (607.0)	2.24^a	2,64	0.12	_pη² = 0.07	61.2 (69.2)	135.5 (131.2)°	333.6 (414.3)^⁎⁎⁎	9.17^a	2,64	<0.001	_pη² = 0.22
Years of use	11.0 (6.2) n = 35	12.3 (7.7)	13.4 (6.9)	0.65^a	2,61	0.53	_pη² = 0.02	12.4 (6.6) n = 35	14.1 (8.5)	15.0 (7.4)	0.78^a	2,61	0.46	_pη² = 0.03
Nicotine
Smoking (yes/no)	27/11	12/3	14/0	5.20^b	2	0.07	V = 0.28	28/10	12/3	14/0	4.54^b	2	0.10	V = 0.26
Cigarettes per day^e	5.0 (6.2)	9.9 (11.3)	12.5 (8.1)^⁎	5.33^a	2,64	0.007	_pη² = 0.14	4.7 (6.4)	10.3 (14.2)	11.8 (7.5)^⁎	4.32^a	2,64	0.02	_pη² = 0.12
Years of use	7.1 (6.9)	9.1 (8.4)	14.5 (6.1)^⁎⁎	5.42^a	2,64	0.007	_pη² = 0.15	8.1 (7.5)	10.6 (9.3)	16.1 (6.7)^⁎⁎	5.46^a	2,64	0.006	_pη² = 0.15
Cannabis
Grams per week^e	0.0 (0.2)	2.3 (7.2)	2.4 (5.0)	2.59^a	2,64	0.08	_pη² = 0.08	0.1 (0.2)	0.2 (0.5)°	1.5 (2.4) ^⁎⁎	8.03^a	2,64	0.001	_pη² = 0.20
Years of use	3.7 (5.6) n = 37	7.9 (8.7)	12.9 (6.6)^⁎⁎⁎	10.25^a	2,63	<0.001	_pη² = 0.25	3.9 (5.8) n = 37	8.9 (9.9)	13.6 (7.1)^⁎⁎⁎	9.89^a	2, 63	<0.001	_pη² = 0.24
Cumulative dose (g)	73 (228) n = 37	1719 (2226)	3324 (4519)^⁎⁎⁎	10.66^a	2,63	<0.001	_pη² = 0.25	1.8 (7.1) n = 37	30.0 (53.6)	50.5 (70.3)^⁎⁎	8.11^a	2,64	0.001	_pη² = 0 0.20
Last consumption (d)^h	58 (61) n = 10ⁱ	15 (20) n = 8^k	22 (17) n = 9	3.24^a	2,24	0.06	_pη² = 0.21	69 (63) n = 11	21 (36)^⁎ n = 10	11 (11)^⁎⁎ n = 12	6.00^a	2,30	0.006	_pη² = 0.29
Urine toxicology (neg/pos)^g	37/1	11/4	11/3	7.42^b	2	0.02	V = 0.33	37/1	12/3	11/3	5.75^b	2	0.06	V = 0.29
Amphetamine
Grams per week^e	0.0 (0.0)	0.3 (0.5)^⁎⁎° n = 14	0.0 (0.1)	6.16^a	2,63	0.004	_pη² = 0.16	0.0 (0.0)	0.0 (0.0)°	0.1 (0.2)^⁎⁎	7.28^a	2,64	0.001	_pη² = 0.19
Years of use	0.0 (0.0)	4.0 (4.2)^⁎⁎⁎	2.1 (2.9)^⁎ n = 13	16.46^a	2,63	<0.001	_pη² = 0.34	0.1 (0.5)	4.4 (4.4)^⁎⁎⁎	2.4 (3.0)^⁎ n = 13	17.05^a	2,63	<0.001	_pη² = 0.35
Cumulative dose (g)	0 (0)	75 (128)	154 (307)^⁎⁎	5.63^a	2,64	0.006	_pη² = 0.15	0.1 (0.8)	9.1 (31.8)	3.7 (5.5)	1.93^a	2, 65	0.16	_pη² = 0.06
Last consumption (d)^h	–	27.5 (24.9) n = 8	67.7 (70.8) n = 5	2.25^a	1,11	0.16	_pη² = 0.17	30 (−) n = 1	49 (45) n = 7	37 (48) n = 7	0.16^a	2,12	0.86	_pη² = 0.03
Hair analysis (ng/mg)^d	0.0 (0.0)	1.2 (3.3)	0.6 (1.4)	2.42^a	2,57	0.10	_pη² = 0.08	0.0 (0.0)	0.2 (0.4)	0.5 (1.3)	3.06^a	2,62	0.05	_pη² = 0.09
Urine toxicology (neg/pos)^g	38/0	15/0	15/0	–	–	–	–	38/0	14/1	13/1	2.71^b	2	0.26	V = 0.20
MDMA
Tablets per week^e	0.0 (0.0)	0.2 (0.4)	0.2 (0.5)	2.58^a	2,64	0.08	_pη² = 0.07	0.0 (0.0)	0.1 (0.2)°° n = 14	0.8 (1.2)^⁎⁎⁎	11.55^a	2,63	<0.001	_pη² = 0.27
Years of use	0.1 (0.6)	4.7 (5.4)^⁎⁎⁎	3.9 (4.8)^⁎⁎ n = 13	13.32^a	2,63	<0.001	_pη² = 0.30	0.2 (1.1)	5.3 (6.1)^⁎⁎⁎	4.6 (5.0)^⁎⁎ n = 13	13.46^a	2,64	<0.001	_pη² = 0.30
Cumulative dose (tablet)	0 (2)	107 (210)°	598 (1011)^⁎⁎⁎ n = 13	8.52^a	2,63	0.001	_pη² = 0.21	0.6 (3.5)	4.0 (8.6)°°°	30.6 (36.0)^⁎⁎⁎	16.54^a	2,64	<0.001	_pη² = 0.34
Last consumption (d)^h	–	51.0 (44.4) n = 6	78.2 (67.4) n = 7	0.71^a	1,11	0.42	_pη² = 0.06	91 (−) n = 1	34 (18) n = 7	39 (55) n = 10	0.74^a	2,15	0.49	_pη² = 0.09
Hair analysis (ng/mg)^d	0.0 (0.0)	0.2 (0.3)°	1.2 (2.3)^⁎⁎	6.52^a	2,57	0.003	_pη² = 0.19	0.0 (0.0)	0.2 (0.3)	1.2 (3.3)^⁎	3.59^a	2,63	0.03	_pη² = 0.10
Methylphenidate
Cumulative dose (tablet)	3 (20)	70 (262)	214 (524)^⁎ n = 13	3.20^a	2,63	0.05	_pη² = 0.09	0.00 (0.00)	28.4 (106.4) n = 14	20.7 (70.7)	1.51^a	2,62	0.23	_pη² = 0.05
Hair analysis (ng/mg)^d	0.0 (0.0) n = 30	0.0 (0.0) n = 12	0.0 (0.0) n = 10	1.65^a	2,49	0.20	_pη² = 0.06	0.0 (0.0)	0.1 (0.3)	0.0 (0.0)	1.70^a	2,63	0.19	_pη² = 0.05

Means and SD of all groups (controls, decreasers and sustained users) for both measurement time points.

Significant P values are shown in bold.

Abbreviations: ADHD-SR = ADHD self-rating scale; BDI=Beck Depression Inventory; bl = blonde; blk = black; br = brown; d = day; g = gram; MDMA = 3,4methylenedioxymethamphetamine (“ecstasy”); mg = milligram; MWT-B = Mehrfachwahl-Wortschatz-Intelligenztest; ng = nanogram.

ANVOA group comparisons with significant Sidak post-hoc tests (cocaine user groups vs. controls: *P < .05, **P < .01,***P < .001; Decreasers vs. Sustained Users: °P < .05, °°P < .01,°°°P < .001.

χ²-test for frequency data (cocaine user groups only/all groups); Kramer's V reported as effect-size.

t-test (independent, two-tailed, cocaine users only); Cohen's d reported as effect-size.

Hair samples for four controls and four cocaine users are missing at baseline. At follow-up, hair sample for one sustained user is missing.

Average of use over the last six months.

At baseline the total cumulative dose across lifetime and at follow-up the total dose of cocaine consumed between the two measurement points are meant.

Urine tests classifications (neg/pos) are based on the following cutoff values: amphetamine = 300 ng/ml; cocaine = 150 ng/ml; tetrahydrocannabinol = 50 ng/ml (Substance Abuse and Mental Health Services Administration, 2008). The frequency tests for amphetamine and cannabis included all three groups, whereas for cocaine only the two cocaine user groups.

Days passed until last consumption were averaged only for subjects using the substance within the last six months.

ⁱ

Data for one participant is missing.

Data for 2 participants are missing.