Table 2 Clinical and substance use characteristics of patients with methamphetamine use disorder (n = 408) and heroin use disorder (n = 81)

Duration of drug use (months)

97.23 ± 6.26

243.85 ± 81.25

−21.806

 < 0.001

Quantity of use per month (milligram/month)

10.63 ± 22.02

56.67 ± 68.08

−11.036

 < 0.001

Abstinence duration (months)

12.21 ± 5.70

14.13 ± 4.99

−2.773

0.006

Onset age of drug use (years)

25.10 ± 7.30

23.75 ± 6.44

1.540

0.124

RRS

 Symptom Rumination

8.93 ± 2.42

9.17 ± 2.04

17.859

^a < 0.001

 Brooding

10.21 ± 2.50

10.83 ± 2.16

10.291

^a 0.001

 Reflective Pondering

20.57 ± 5.08

22.51 ± 4.86

3.530

^a 0.061

 RRS Total score

39.71 ± 8.90

42.51 ± 7.84

14.486

^a < 0.001

OCDUS-CV

 Interference of Drug

8.29 ± 3.05

11.07 ± 3.61

−7.263

^b 0.222

 Frequency of Craving

6.96 ± 3.05

8.43 ± 3.11

−3.947

^b 0.001

 Control of Drug

5.69 ± 2.20

6.48 ± 1.89

−3.031

^b 0.05

 OCDUS Total score

20.95 ± 48.60

25.99 ± 6.57

−6.566

^b 0.003