Table 3.
Scaled scores denoting cognitive functioning on the Wechsler Abbreviated Scale of Intelligence (WASI-II) and Wechsler Adult Intelligence Scale (WAIS-IV) for stimulant misusers versus controls.
| Misusers (N=100) | Controls (N=198) | Test statistics, p-value | |
|---|---|---|---|
| WASI-II | Mean ± SD | Mean ± SD | |
| Vocabulary Scaled Score | 12.9 ± 2.1 | 13.2 ± 2.5 | beta: −0.5; 95% Confidence Interval (CI): −1.1, 0.09; p=0.10 |
| Matrix Scaled Score | 11.7 ± 1.8 | 11.5 ± 2.2 | beta: 0.1; 95% CI: −0.4, 0.6; p=0.66 |
| Full Scale IQ | 113 ± 8.9 | 113.5 ± 11.2 | beta: −1.1; 95% CI: −3.7, 1.4; p=0.38 |
| WAIS-IV | |||
| Digit Span Scaled Score | 10.8 ± 2.5 | 11.5 ± 3.0 | beta: −0.8; 95% CI: −1.5, −0.09; p=0.03* |
| Arithmetic Scaled Score | 12.1 ± 2.3 | 12.1 ± 2.5 | beta: −0.1; 95% CI: −0.7, 0.4; p=0.64 |
| Letter Number Scaled Score | 11.2 ± 2.3 | 11.9 ± 2.9 | beta: −0.9; 95% CI: −1.5, −0.2; p=0.01* |
| Digit Symbol Scaled Score | 11.1 ± 2.6 | 11.5 ± 2.9 | beta: −0.5; 95% CI: −1.2, 0.1; p=0.1 |
| Symbol Search Scaled Score | 12.7 ± 2.5 | 12.8 ± 3.2 | beta: −0.2; 95% CI: −0.9, 0.5; p=0.64 |
| Working Memory | 107.7 ± 11.3 | 110.7 ± 14.1 | beta: −3.9; 95% CI: −7.1, −0.7; p=0.02* |
| Processing Speed | 110.6 ± 12.9 | 111.9 ± 15.7 | beta: −1.9, 95% CI: −5.5, 1.6; p=0.3 |
ψ
p-value>0.05 when ADHD was included in the model
*
p-value<0.05 when ADHD was included in the model