Table 1. Demographic characteristics.
| Variable | All participants (n = 15) |
Heroin-dependent Group (HD) (n = 8) |
Control Group (CG) (n = 7) |
p | |||
|---|---|---|---|---|---|---|---|
| mean | s.d. | mean | s.d. | mean | s.d. | ||
| Age (years) | 45.7 | 6.8 | 47.6 | 6.1 | 45.7 | 6.8 | 0.58 |
| Education (years) | 6.4 | 2.7 | 5.9 | 2.8 | 7.0 | 2.4 | 0.43 |
| IQ | 83.0 | 10.5 | 82.9 | 11.4 | 83.1 | 9.3 | 0.97 |
| Cigarettes (mg/per day) | 21.5 | 10.3 | 22.8 | 9.7 | 20.0 | 10.7 | 0.61 |
| History of smoking (years) | 31.3 | 7.4 | 33.6 | 6.7 | 28.7 | 7.3 | 0.89 |
| Anxiety | 85.5 | 21.9 | 95.4 | 22.1 | 74.1 | 15.2 | 0.047* |
| Duration of heroin use (years) | N/A | N/A | 29.0 | 9.7 | N/A | N/A | N/A |
| Duration of heroin abstinence (years) | N/A | N/A | 2.39 | 3.4 | N/A | N/A | N/A |
| Average heroin dosage (g/day) | N/A | N/A | 0.6 | 0.4 | N/A | N/A | N/A |
| Methadone treatment dosage (mg) | N/A | N/A | 30.0 | 26.9 | N/A | N/A | N/A |
The p values are reported for a two-sample t test (for age, years of education, IQ, daily cigarette consumption, years of smoking, and level of anxiety) comparing abstinent heroin-dependent subjects (HDs) with the controls (CGs). IQ was assessed with the Wechsler Adult Intelligence Scale version 4. Anxiety scores were scaled with the adult State-Trait Anxiety Inventory (STAI73). Abbreviation: Standard deviation (s.d.). *p < 0.05.