Table 2.
Descriptive statistics and analysis of primary outcome measures
| Placebo n = 29 |
10mg Amphetamine n = 16 |
20mg Amphetamine n = 24 |
Amphetamine effects | ||||||||
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| Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | F | DF | p | ηp2 | Adiusted α | |
| Conners’ CPT | |||||||||||
| Omissions (Misses) | 8.03 | 23.55 | 1.88 | 2.92 | 2.63 | 3.10 | 1.20 | 2, 62 | 0.308 | 0.04 | 0.005 |
| Comissions (False Alarm) | 11.66 | 7.78 | 11.94 | 7.25 | 11.33 | 6.21 | 0.02 | 2, 62 | 0.982 | 0.00 | 0.005 |
| Hit Reaction Time (HRT) | 392.58 | 64.23 | 357.22 | 48.32 | 365.09 | 47.94 | 2.42 | 2, 62 | 0.098 | 0.07 | 0.005 |
| HRT Error | 6.50 | 4.96 | 4.58 | 1.84 | 4.54 | 1.59 | 2.71 | 2, 62 | 0.075 | 0.08 | 0.005 |
| HRT Variability | 10.24 | 13.89 | 6.86 | 6.01 | 7.91 | 9.66 | 1.58 | 2, 62 | 0.215 | 0.05 | 0.005 |
| Detectability (D′) | 0.81 | 0.47 | 0.78 | 0.40 | 0.81 | 0.42 | 0.02 | 2, 62 | 0.982 | 0.00 | 0.005 |
| Response Style (β) | 0.97 | 1.05 | 0.49 | 0.40 | 0.69 | 0.69 | 1.70 | 2, 62 | 0.191 | 0.05 | 0.005 |
| Perseverations | 1.03 | 2.87 | 1.00 | 3.48 | 0.58 | 2.45 | 0.21 | 2, 62 | 0.815 | 0.01 | 0.005 |
| HRT Across Block | −0.005 | 0.023 | −0.003 | 0.019 | −0.009 | 0.021 | 0.45 | 2, 62 | 0.637 | 0.01 | 0.005 |
| HRT Error Across Block | 0.035 | 0.068 | 0.033 | 0.077 | −0.024 | 0.056 | 6.50 | 2, 62 | 0.003 | 0.17 | 0.005 |
| ADHD Confidence Index | 45.31 | 21.85 | 33.78 | 22.08 | 30.88 | 21.86 | 3.88 | 2, 62 | 0.026 | 0.11 | 0.005 |
| Iowa Gambling Task | |||||||||||
| Total Score | 9.31 | 27.73 | 12.88 | 21.20 | 14.25 | 33.99 | 0.23 | 2, 62 | 0.795 | 0.01 | 0.006 |
| Deck A | 14.34 | 4.78 | 16.25 | 6.89 | 14.58 | 5.30 | 0.54 | 2, 62 | 0.585 | 0.02 | 0.006 |
| Deck B | 31.00 | 13.72 | 27.31 | 9.89 | 28.29 | 13.79 | 0.56 | 2, 62 | 0.577 | 0.02 | 0.006 |
| Deck C | 22.34 | 11.30 | 23.56 | 6.25 | 23.92 | 15.53 | 0.12 | 2, 62 | 0.888 | 0.00 | 0.006 |
| Deck D | 32.31 | 13.62 | 32.88 | 11.40 | 33.21 | 14.48 | 0.04 | 2, 62 | 0.957 | 0.00 | 0.006 |
| Net 1 | −4.21 | 7.32 | −2.63 | 7.75 | −6.42 | 6.59 | 1.74 | 2, 62 | 0.185 | 0.05 | 0.006 |
| Net 2 | −0.48 | 6.56 | 0.50 | 4.16 | 3.25 | 9.47 | 1.78 | 2, 62 | 0.178 | 0.05 | 0.006 |
| Net 3 | 4.14 | 9.90 | 1.75 | 8.03 | 4.00 | 11.05 | 0.39 | 2, 62 | 0.678 | 0.01 | 0.006 |
| Net 4 | 1.86 | 8.77 | 5.25 | 8.29 | 6.42 | 10.06 | 1.88 | 2, 62 | 0.161 | 0.06 | 0.006 |
| Wisconsin Card Sorting Task | |||||||||||
| Total Correct | 48.21 | 8.17 | 51.63 | 5.40 | 48.67 | 7.84 | 0.00 | 2, 62 | 0.988 | 0.00 | 0.006 |
| Total Errors | 15.72 | 8.16 | 12.38 | 5.40 | 15.33 | 7.84 | 0.00 | 2, 62 | 0.972 | 0.00 | 0.006 |
| Persevarative Errors | 9.48 | 6.52 | 7.00 | 3.31 | 7.50 | 2.98 | 0.50 | 2, 62 | 0.484 | 0.01 | 0.006 |
| Nonperseverative Errors | 6.24 | 3.82 | 5.38 | 3.36 | 7.83 | 6.38 | 0.61 | 2, 62 | 0.439 | 0.01 | 0.006 |
| Conceptual Level Responses | 43.90 | 11.92 | 48.13 | 9.93 | 44.92 | 10.66 | 0.00 | 2, 62 | 0.954 | 0.00 | 0.006 |
| Categories Copleted | 3.52 | 1.35 | 4.06 | 1.24 | 3.63 | 1.38 | 0.03 | 2,62 | 0.867 | 0.00 | 0.006 |
| Trials to 1st Category Complete | 14.45 | 11.07 | 14.00 | 9.31 | 11.46 | 2.62 | 0.87 | 2, 62 | 0.422 | 0.03 | 0.006 |
| Failure to Maintain Set | 0.45 | 0.83 | 0.31 | 0.48 | 0.46 | 0.72 | 1.84 | 2, 62 | 0.180 | 0.03 | 0.006 |
Statistical tests meeting traditional significance have been highlighted in bold. Effect size and the Bonferroni corrected significance are also highlighted in bold when adjusted significance criteria were met.