Table 1.
Demographic and clinical information of OD (n = 18) and HC (n = 20) groups included in the analysis.
| OD group | HC group | p‐value | |
|---|---|---|---|
| Age | 34.8 (6.3) | 31.6 (7.2) | 0.15 |
| IQ | 103.1.9 (7.7) | 114.1 (4.7) | <0.05 |
| Years of education | 11.5 (2.2) | 16.5 (3.3) | <0.05 |
| No. of right handers | 16 (89 percent) | 18 (90 percent) | 0.91 |
| No. of smokers (nicotine) | 13 (72 percent) | 9 (45 percent) | 0.09 |
| Clinical Variables for OD group | |||
| Years of opioid dependence | 12.8 (7.7) | — | |
| Average daily opioid use (g) | 0.7 (0.6) | — | |
| Age of first use (years) | 20.3 (4.3) | ||
| No. who primarily smoke/inject/ or use both methods for heroin administration | 5 (28 percent)/5 (28 percent)/8 (44 percent) | — | |
| No. of OD group with current/past history of: | — | ||
| Alcohol dependence | 7 (39 percent) | — | |
| Cocaine dependence | 7 (39 percent) | ||
| Amphetamine dependence | 1 (6 percent) | — | |
| Benzodiazepine dependence | 3 (17 percent) | — | |
| Heroin dependence only (except nicotine) | 6 (33 percent) | — |
Age, IQ, years of education, years of dependence, average daily amount used and age of first use expressed as mean and standard deviation (in brackets). All other variables expressed as frequency and proportion of group (in brackets). P‐values taken from independent t‐tests for continuous data and chi‐squared tests for frequency data.