Table 5.
Results of the Meta-Analysis of 14 Whole-Brain fMRI Studies in ADHD: Regional Differences between ADHD Patients on an Acute Dose of Psychostimulants/Methylphenidate Relative to Placebo or Off Their Usual Clinical Dose of Psychostimulants/Methylphenidate
| Contrast | Talairach x, y, z Coordinates | SDM z-Value | p Value | Number of Voxels | Cluster Breakdown (Number Voxels) |
|---|---|---|---|---|---|
| All 14 Datasets | |||||
| Stimulants > Placebo/Off Medication | |||||
| Right inferior frontal gyrus, extending to insula and superior temporal gyrus | 42, 20, −12 | 1.469 | <.000001 | 607 | BA 47 (339); BA 13 (111); BA 38 (68); BA 11 (44); claustrum (19); BA 45 (26) |
| Stimulants < Placebo/Off Medication | |||||
| Right dorsal anterior cingulate/supplementary motor area | 8, 10, 44 | −1.432 | <.000005 | 691 | BA 32 (317); BA 6 (144); BA 8 (103); BA 24 (127) |
| Subgroup Analysis of 10 fMRI Studies that Compared Methylphenidate Effects in Medication-Naïve ADHD Patients | |||||
| MPH > Placebo | |||||
| Right inferior frontal gyrus, extending to insula and superior temporal gyrus | 42, 20, −12 | 1.745 | <.000005 | 632 | BA 47 (356); BA 13 (113); BA 38 (68); BA 11 (48); BA 45 (47) |
| MPH < Placebo | |||||
| Right dorsal anterior cingulate/supplementary motor area | 12, 12, 44 | −1.586 | <.000001 | 728 | BA 32 (293); BA 6 (176); BA 24 (132); BA 8 (127) |
Meta-analysis was conducted at p < .005, z = 1, and a cluster size of >10 voxels.
ADHD, attention-deficit/hyperactivity disorder; BA, Brodmann area; fMRI, functional magnetic resonance imaging; MPH, methylphenidate; SDM, signed differential mapping.