Appendix 2—table 1.
Mean(SD) scores for neuropsychological tests and self-report questionnaires for the group that received placebo and MPH on day 1. Significance levels for the between group differences are reported. Self-report questionnaires include the Barratt Impulsiveness Scale (BIS-11; Patton et al., 1995), the Behavioural Inhibition Scale/Behavioural Activation Scale (BISBAS; Carver and White, 1994), Need for Cognition Scale (NCS, Cacioppo et al., 1984), Multidimensional Scale of Perceived Social Support (MSPSS, Zimet et al., 1988), Barratt Simplified Measure of Social Status (BSMSS, Barratt, 2006), Sociable and Aggressive Dominance Questionnaire (SADQ, Kalma et al., 1993), Beck Depression Inventory II (BDI-II; Beck et al., 1996), Spielberger Trait Anxiety Inventory (STAI; Spielberger et al., 1983).
| Group 1 Placebo Day 1 |
Group 2 MPH Day 1 |
|||
|---|---|---|---|---|
| Neuropsychological tests | Listening span | 5.0 (0.9) | 4.6 (1.2) | p=0.16 |
| NLV | 94.4 (7.6) | 92.6 (7.6) | p=0.23 | |
| Digit span – forward | 17.2 (3.7) | 16.2 (3.6) | p=0.16 | |
| Digit Span - backward | 14.7 (3.4) | 13.9 (2.7) | p=0.22 | |
| Self-report questionnaires | Impulsivity (BIS-11) | 63.5 (8.9) | 60.2 (7.9) | p=0.052* |
| Behavioural inhibition (BIS) | 16.4 (3.7) | 16.3 (3.5) | p=0.90 | |
| Behavioural activation (BAS) | 22.8 (3.9) | 23.9 (4.0) | p=0.17 | |
| Need for cognition (NCS) | 64.5 (10.5) | 62.2 (10.5) | p=0.26 | |
| Social support (MSPSS) | 71.1 (10.1) | 69.3 (9.6) | p=0.35 | |
| Social status (BSMSS) | 49.8 (12.1) | 45.9 (12.7) | p=0.11 | |
| Social dominance (SADQ) | 4.1 (0.9) | 4.1 (0.8) | p=0.82 | |
| Aggressive dominance (SADQ) | 2.6 (0.6) | 2.6 (0.6) | p=0.69 | |
| Depressive symptoms (BDI-II) | 3.5 (3.7) | 3.6 (3.9) | p=0.97 | |
| Anxiety symptoms (STAI) | 32.4 (6.6) | 32.4 (7.2) | p=1.0 |
*One subject had an outlying score on the BIS-11. Without outlier: p=0.09.