Table 1. Demographic Characteristics of Participants.
| Characteristic | Experiment 1 (N=22) |
Experiment 2 (N=32) |
Experiment 3 (N=48) |
P-value | |||
|---|---|---|---|---|---|---|---|
| Propranolol (N=16) | Placebo (N=16) | Cortisol (N=17) | C with P (N=15) | Propranolol (N=16) | |||
| Age (years) | 30.45±4.37 | 28.61±5.35 | 27.88±4.32 | 30.52±4.73 | 30.22±5.40 | 29.80±5.91 | 0.61 |
| Education (years) | 8.55±1.77 | 9.60±1.92 | 9.75±2.57 | 9.20±1.56 | 9.40±2.31 | 9.11±1.90 | 0.91 |
| Years of heroin abuse | 5.84±3.18 | 5.27±2.91 | 5.16±3.54 | 6.42±3.21 | 5.81±3.60 | 6.70±3.81 | 0.74 |
| Amount of heroin use per day (g) | 0.59±0.31 | 0.71±0.25 | 0.57±0.38 | 0.60±0.41 | 0.70±0.52 | 0.71±0.31 | 0.70 |
| Months of heroin abstinence | 3.41±1.07 | 3.13±1.76 | 2.78±1.24 | 3.20±2.61 | 3.22±2.70 | 3.11±2.20 | 0.98 |
Abbreviation: C with P, cortisol with propranolol.
All results are mean±SD. Experiment 1, individuals given psychosocial stress; Experiment 2, participants were randomly assigned to two subgroups: administered propranolol (n=16) or placebo (n=16) at 1 h before psychosocial stress; Experiment 3, participants were randomly assigned to three subgroups: administered cortisol (n=17), cortisol with propranolol (n=15), or propranolol alone (n=16).