Table 1.
Characteristics of research participants
| Entire sample (Time 1) |
Subsamples (Times 1 and 2) |
|||
| Variable | Control | MA-dependent | Control | MA-dependent |
| Number/group | 28 | 27 | 21 | 18 |
| Age, years, M (SD) | 33.3 (7.9) | 33.9 (7.5) | 35.2 (8.0) | 34.1 (6.9) |
| Shipley-Hartford Vocabulary scorea, M (SD) | 29.4 (4.3) | 28.1 (4.6) | 30.3 (3.3) | 28.7 (3.2) |
| Education, in years, M (SD) | 15.1 (2.5) | 12.7 (1.9)** | 14.7 (2.4) | 12.9 (1.7)* |
| Mother's education, in years, M (SD) | 14.2 (2.2) | 13.3 (2.6) | 13.9 (2.2) | 13.1 (2.8) |
| Wender-Utah Rating Scale, M (SD) | 17.3 (18.2) | 24.7 (17.2) | 18.5 (20.5) | 28.6 (17.6) |
| Ethnicity, n | ||||
| White | 19 | 17 | 15 | 11 |
| African American | 7 | 2 | 4 | 1 |
| Hispanic | 1 | 5 | 1 | 4 |
| Other | 1 | 3 | 1 | 2 |
| Gender, n | ||||
| Male | 14 | 17 | 12 | 13 |
| Female | 14 | 10 | 9 | 5 |
| Cigarette smokers, n | 13 | 21** | 10 | 14* |
| Duration of MA use, in years, M (SD) | — | 7.6 (6.9) | — | 8.0 (6.3) |
| Grams MA/week, M (SD) | — | 4.7 (5.8) | — | 5.4 (6.7) |
Notes: MA = methamphetamine.
a
Taken as an index of premorbid IQ.
*
Significantly different from the control group, p < .05;
**
p < .01.