Table 2.
Neuropsychological test performance at assessment Time 1
| Domain/tests | Control M (SD) | MA-dependent M (SD) |
| Attention/processing speedc | ||
| Trails Aa | 29.0 (11.0) | 29.3 (15.5) |
| Stroop–words | 101.7 (19.0) | 102.2 (16.6) |
| Stroop–colors | 75.6 (11.7) | 68.8 (10.5)* |
| Working memory | ||
| Backward digit span | 4.69 (1.54) | 4.33 (1.24) |
| Sentence span | 2.50 (0.76) | 2.42 (1.03) |
| Missing digit span | 6.46 (1.86) | 6.48 (1.93) |
| Learning/memory | ||
| Selective Reminding Test | ||
| Total | 120.3 (15.7) | 110.3 (14.3) |
| Intrusionsa | 2.04 (2.56) | 2.64 (3.05) |
| Repeated Memory Test | ||
| Word recall | 4.18 (2.87) | 2.56 (2.42) |
| Picture recall | 8.11 (2.50) | 5.89 (2.42) |
| Word recognition | 14.00 (5.00) | 11.30 (4.57) |
| Picture recognition | 19.14 (4.58) | 18.04 (3.91) |
| Timed executive functioning | ||
| Trails Ba | 65.4 (30.2) | 68.6 (27.7) |
| Stroop–color/word | 44.7 (8.68) | 38.8 (9.52) |
| FAS | 42.9 (10.1) | 44.0 (10.0) |
| Untimed executive functioning | ||
| Wisconsin Card Sorting, perseverative errorsa | 12.2 (10.9) | 13.5 (9.7) |
| Discrimination learning | 22.2 (7.02) | 20.0 (7.02) |
| Logical problems | 6.26 (1.63) | 5.74 (1.85) |
| Composite battery scoreb | 0.01 (0.60) | −0.31 (0.45)* |
Notes: Sample size for the control group was n = 24–28 per test; for the methamphetamine (MA) group n = 25–27, with the exception of the Wisconsin Card Sorting test with some missing data (ns = 13 and 18, respectively). Unless specified, higher scores indicate better performance. FAS = Controlled Oral Word Fluency.
a
Higher scores indicate worse performance;
b
mean of all test scores standardized (z) to the control sample;
c
significant omnibus statistic for multivariate analysis of variance.
*
p < .05.