The Action of Stimulant Medication in Attention Deficit Disorder with Hyperactivity: Dopaminergic, Noradrenergic, or Both?

Error Patterns on the Continuous Performance Test in Non‐Medicated and Medicated Samples of Children With and Without ADHD: A Meta‐Analytic Review

“…Biased estimates were presented in the result section for two reasons: first, both biased and unbiased estimates revealed identical patterns of results; second, biased estimates are better indicators of the veridical magnitude of the effects of diagnosis and drug treatment on the error types. Barkley et al, 1991Barkley et al, 1989Barkley et al, 1988Coons et al, 1987Fitzpatrick et al, 1992Levy & Hobbes, 1988Matier et al, 1992Michael et al, 1981Milich et al, 1989Pelham et al, 1990Rapport et al, 1987Rapport et al, 1986Taylor et al, 1987Werry & Aman, 1975Yepes et al, 1977 Study Barkley et al, 1991Barkley et al, 1989Barkley et al, 1988Coons et al, 1989Fitzpatrick et al, 1992Levy & Hobbes, 1988Matier et al, 1992Michael et al, 1981Milich et al, 1989Pelham et al, 1990Rapport et al, 1987Rapport et al, 1986Taylor et al, 1987Werry & Aman, 1975Yepes et al, 1977 Size 40 Barkley et al, 1992Barkley et al, 1990Chee et al, 1989Halperin et al, 1992Halperin et al, 1990Hooks et al, 1994Horn et al, 1989Newcorn et al, 1989O'Dougherty et al, 1984Schachar et al, 1988Seidel & Joschko, 1991 Omission…”

“…Table 11 Table 9 Review of Statistical Outcomes* on Errors of Omission and Methylphenidate Drug Condition Study Barkley et al, 1991Barkley et al, 1989Barkley et al, 1988Coons et al, 1987Fiztpatrick et al, 1992Levy & Hobbes, 1988Matier et al, 1992Michael et al, 1981Milich et al, 1989Pelham et al, 1990Rapport et al, 1987Rapport et al, 1986Taylor et al, 1987Werry & Aman, 1975Yepes et al, 1977 Omission…”

“…A total of 14 studies were entered in the analysis with ES values ranging from -0.63 (Taylor et al, 1987) to 1.84 (Levy & Hobbes, 1988). Errors of commission ES under the placebo and methylphenidate conditions were submitted to the meta-analysis, which revealed that methylphenidate significantly reduced the number of errors of commission in children with ADHD (95%CI = 0.64 ± 0.22) when compared to placebo conditions.…”

The Dopamine Theory of Attention Deficit Hyperactivity Disorder (ADHD)

“…The nor-adrenergic hypothesis rests primarily on clinical studies showing improved behaviour, with nor-adrenergic agonists, but there are few animal models or objective psychometric data on which to model the hypothesis. As pointed out by Levy and Hobbes [9] desipramine studies [6] have shown no improvement on objective vigilance tests such as the Continuous Performance Test (CPT). A MAO-A study (81 was carried out on a small number (N = 6) of children.…”

Dopamine vs Noradrenaline: Inverted-U Effects and ADHD Theories

“…For example, Harris and Baldessarini showed that the dexamphetamine d-isomer was fourfold more potent than the l-isomer in striatal tissue, but only twofold more potent than l-amphetamine in inhibiting norepinephrine (NE) uptake, which could account for the fourfold difference of d-vs l-amphetamine, in inducing stereotypic behaviour in the rat, suggesting a DA effect [6]. Levy and Hobbes utilized the CPT to investigate the effect of a single pre-dose of haloperidol (0.04 mg kg (1 ) on improvements in vigilance produced by methylphenidate (MPH) in 12 boys diagnosed with attention-deficit disorder with hyperactivity [7]. Haloperidol was shown to block the improvements on all the vigilance subtests, again suggesting a DA effect.…”