Table 2.
Cognitive Performance of Research Participants
| Healthy Control | Methamphetamine-Dependent | |
|---|---|---|
| Cognitive Battery Overall Mean** | −0.01 ± 0.59 (−1.81 to 1.24) 5% “low” | −0.41 ± 0.56 (−2.2 to 0.7) 14% “low” |
| Processing Speed/Attention | ||
| Trailmaking Part Aa | 24.7 ± 7.6 (13 to 44) 15% “low” | 25.8 ± 7.3 (13 to 47) 13% “low” |
| Stroop Word Naming* | 104.7 ± 15.9 (68 to 148) 15% “low” | 95.2 ± 14.4 (60 to 124) 21% “low” |
| Stroop Color Naming* | 77.0 ± 11.7 (54 to 103) 14% “low” | 70.9 ± 10.2 (48 to 92) 20% “low” |
| Learning/Memory | ||
| Selective Reminding Task – Total Score† | 119.8 ± 14.2 (68 to 139) 13% “low” | 112.3 ± 15.3 (70 to 140) 20% “low” |
| Executive Function | ||
| Stroop Word-Color Interference* | 49.3 ± 10.3 (33 to 72) 22% “low” | 43.7 ± 9.2 (22 to 68) 22% “low” |
| Trailmaking Part Ba | 60.8 ± 26.2 (26 to 155) 10% “low” | 67.3 ± 21.5 (36 to 119) 16% “low” |
| Verbal Fluency (F, A, S) | 44.8 ± 12.9 (17 to 74) 14% “low” | 38.9 ± 11.1 (15 to 68) 23% “low” |
| Wisconsin Card Sorting (Perseverative Errors)a | 10.5 ± 8.3 (3 to 38) 14% “low” | 13.3 ± 10.5 (4 to 52) 17% “low” |
| Stop Signal Reaction Timea† | 222.6 ± 73.5.2 (79.7 to 505.1) 11% “low” | 253.5 ± 80.9 (89.1 to 534.7) 21% “low” |
Note. Values are means ± SDs, with the range in parentheses.
a
Higher scores indicate worse performance. The “low” percentage is the percent of the scores that placed ≥ 1 SD below the control sample mean. The symbols *, ** and † indicate difference between the groups at p < 0.05, p < 0.01 and p < 0.10 (trend), uncorrected for multiple comparisons.