Table 1.
Demographic and baseline measures for the groups of stimulant-dependent individuals (n = 18) and non-drug-taking comparison volunteers (n = 18)
| Group | Healthy control | Stimulant-dependent | F | df | P values |
|---|---|---|---|---|---|
| Age (years) | 32.7 (±6.9) | 34.3 (±7.2) | 0.47 | 1, 34 | 0.498 |
| Gender ratio (male/female) | 15:3 | 15:3 | Fisher′s exact | 1.000 | |
| Ethnic ratio (Caucasian/Afro-Caribbean) | 17:1 | 16:2 | Fisher′s exact | 1.000 | |
| Verbal intelligence quotient (NART) | 108.4 (±6.0) | 109.0 (±8.1) | 0.55 | 1, 34 | 0.816 |
| Years of education | 12.4 (±1.8) | 11.2 (±1.0) | 6.85 | 1, 34 | 0.013 |
| Depressive mood (BDI-II total score) | 1.1 (±2.4) | 9.3 (±11.1) | 9.50 | 1, 34 | 0.004 |
| Impulsivity (BIS-11 total score) | 62.0 (±7.2) | 82.0 (±9.5) | 50.4 | 1, 34 | <0.001 |
| Duration of stimulant abuse (years) | – | 11.7 (±7,4) | – | – | – |
| Compulsivity of stimulant abuse (OCDUS score) | – | 26.5 (±7.9) | – | – | – |
| Frequency of stimulant use (times per week) | – | 5.4 (±2.0) | – | – | – |
NART National Adult Reading Test, BIS-11 Barratt Impulsiveness Scale, BDI-II Beck Depression Inventory, OCDUS Obsessive-Compulsive Drug Use Scale