Table 2.
Sample and study design features, and ADHD symptom specific outcome measures, of 6 double-blind, placebo controlled studies on amphetamines in adult ADHD
| Authors | N | Rank of current comorbiditya | Length of study | Type of amphetamine and mean dose (mg/day) | Efficacy; physician rated responseb | Efficacy; patient rated responseb | ||
|---|---|---|---|---|---|---|---|---|
| Paterson 1999 | 45 | Low | 6 weeks | Dexamphetamine 20–25 mg/day |
Dexamph. Placebo |
58% <10% |
Dexamph. sign. better than Placebo | |
| Spencer 2001 | 27 | Low | 3 weeks | Mixed amphetamine salts (MAS) 53.7 mg/day |
MAS Placebo |
70% 7% |
||
| Taylor 2001 | 17 | Low | 2 weeks | Dexamphetamine 10.2 mg/day |
Dexamph. sign. better than Placebo | |||
| Taylor 2000 | 22 | Low | 2 weeks | Dexamphetamine 21.8 mg/day |
Dexamph. 48% Significantly better than Placebo | |||
| Weisler 2006 | 255 | Low | 4 weeks | Mixed amphetamine salts-extended release (MAS-XR) Fixed dose 20/40/60 mg/day |
MAS-XR 20 mg 30 mg 40 mg Placebo Effect size |
58% 54% 61% 34% 0.8 |
||
| Weiss 2006 | 98 | Low | 20 weeks | Dexamphetamine max. 40 mg/day |
Dexamph. Placebo |
64% 17% |
||
The study was ranked as low in current comorbidity if there was no or very sparse information on comorbidity, only lifetime comorbidity presented, or low numbers of comorbid disorders like anxiety and mood disorders only. The study was ranked as moderate in current comorbidity if the sample had more than 25% current comorbidity on major depression, substance abuse or alcohol abuse, and/or personality disorders. Studies presenting more than 75% current comorbidity on major depression, substance abuse or alcohol abuse, and/or personality disorders were ranked as high comorbidity.
When available the measures presented are response rates defined as percent of patients experiencing >30% reduction of ADHD symptoms on an ADHD rating scale, and/or much or very much improved on Clinical Global Impression-Improvement (CGI-I). If this definition was not used, we present the response rates as defined by the paper, or effect size (computed by taking the mean outcome score of active treatment minus the mean outcome score of control/placebo and dividing the result by the pooled standard deviation).