Table 4.

Comparison between MA- and OS-group at baseline T0

	MA-group	OS-group	P
n	55	55
Male	42 (76.4%)	47 (85.5%)	0.23
Age	30.0 (± 5.3)	32.0 (± 7.7)	0.12
Number of withdrawals (n = 48)	3.0 (± 4.1)	3.0 (± 4.1)	0.98
Raven‘s IQ (MA n = 50, OS n = 54)	93.7 (± 13.5)	100.1 (± 13.6)	0.02
Cognitrone working speed (MA n = 53, OS n = 54)	49.1 (± 8.0)	54.3 (± 9.0)	0.002
Cognitrone accuracy (MA n = 53, OS n = 54)	43.0 (± 8.9)	47.1 (± 9.8)	0.03
Personality factors	n = 37	n = 42
Neuroticism	22.8 (± 6.7)	25.1 (± 9.7)	0.24
Extraversion	25.0 (± 6.0)	25.2 (± 7.5)	0.89
Openness	26.3 (± 5.6)	28.6 (± 6.7)	0.11
Agreeableness	26.6 (± 4.2)	27.9 (± 6.8)	0.33
Conscientiousness	29.0 (± 5.6)	31.9 (± 6.6)	0.04
BDI-II Score (MA n = 42, OS n = 54)	13.6 (± 10.8)	16.8 (± 11.3)	0.17
HAMD Score (MA n = 46, OS n = 42)	5.3 (± 4.8)	8.3 (± 7.9)	0.04
SCL-PSDI Score (MA n = 39, OS n = 40)	53.5 (± 11.1)	59.3 (± 10.1)	0.02
Wursk Score (MA n = 36, OS n = 40)	n = 3628.6 (± 16.7)	n = 4030.8 (± 15.1)	0.56
Craving (MA n = 39, OS n = 40)	13.9 (± 9.5)	14.2 (± 8.0)	0.87
Years of education	n = 52	n = 50	0.048
≤ 9 yr	35	24
≥ 10 yr	17	26
Employment	n = 51	n = 48	0.19
Unemployed	43	33
Employed	4	7
Other (e.g., retiree)	4	8
Ever injected	n = 49	n = 40	0.75
	7	4

Data displays means ± standard deviation or number of participants (education and employment). Different n result from missing values. BDI-II: Becks Depression Inventory-II; HAMD: Hamilton Depressive Rating Scale; MA: Methamphetamine; OS: Other substances; SCL: Symptom Checklist; Wursk: Wender Utah Rating Scale-short Version.