Table 1 Demographics.

Age: mean (95%CI)

42.0 (38.5–45.5)

40.7 (36.0–45.4)

NS

Sex: Male/Female

17 M/4 F

15 M/9 F

Fisher’s test; NS

Race: White/Black/Other

18/0/3

12/8/4

Fisher’s test; p = 0.006

Body mass index (BMI)

32.3 (29.4–35.3)

26.7 (24.9–28.6)

U = 110; p = 0.0009

Sleep hours in the night prior to the blood sample

6.54 (5.6–7.5)

6.51 (5.9–7.2)

NS

PSS-10 Perceived stress score^a;

Score range: 0–40

20.5 (17.7–23.3)

n = 20

12.3 (9.5–16.0)

U = 104; p = 0.001

BDI-II Depression score^a;

Score range: 0–63

15.5 (9.9–21.2)

n = 19

3.8 (1.8–5.7)

U = 78; p = 0.0001

BAI Anxiety score^a;

Score range: 0–63

14.1 (8.8–19.4)

n = 20

2.8 (1.1–4.4)

U = 85.5; p = 0.0001

Subjective opioid withdrawal scale (SOWS) at screening;

Score range: 0–64

4.1 (1.6–6.5)

N/A

Age of first use of heroin^b

23.6 (17.4–27.8)

n = 20

N/A

N/A

Age of onset of regular use of heroin^b

25.1 (21.2–28.9)

n = 20

N/A

N/A

Years of regular heroin use^b

8.5 (5.9–11.2)

n = 19

N/A

N/A

Heroin abstinence duration in days

198 (130–268)

range: 1-634

N/A

N/A

Methadone daily dose in mg^c

91.9 (63–121)

n = 16

N/A

N/A

Years of regular alcohol use^b

12.3 (5.9–18.6)

n = 17

13.2 (6.6–19.8)

n = 18

NS

Years of regular cannabis use^b

10.4 (5.9–14.9)

n = 15

1.3 (0.1–2.5)

n = 14

U = 85.5; p = 0.0001