Table 2. Connectivity within the Cortico-striato-thalamo-cortical loops.
| Authors | Sample | Methods (seeds) | Medication Status | Findings |
|---|---|---|---|---|
| Cao et al. 2009 | N = 42 with 19 ADHD children and 23 controls; 11-16 years. | Seed-based (putamen) | Medication-naïve | Hypoconnectivity between left putamen and NAcc in children with ADHD correlated with ADHD symptom severity. (See Table 1 for additional results.) |
| Tian et al. 2006 | N = 16 with 8 ADHD and 8 controls; 11-15 years. | Seed-based (dACC) | 7 patients medication-free for at least half a year; 1 off medication for 48 hours | Hyperconnectivity between dACC and bilateral thalamus, bilateral cerebellum, bilateral insula and bilateral brainstem in ADHD youth. |
| Mills et al. 2012 | N = 67 with 24 ADHD children and 43 controls; 7-11 years. | Seed-based; (thalamus) | Most patients discontinued 24 to 48 hours before scan | Connectivity of five thalamic regions was correlated with spatial span working memory in children with and without ADHD. Connections between the thalamus and basal ganglia were altered in ADHD and correlated to spatial working memory. |
| Posner et al. 2013 | N = 42 with 22 ADHD children and 20 controls; 7-12 years. | Seed-based; (DLPFC and VS) | Medication-naïve | Hypoconnectivity between VS and anterior prefrontal cortex and between the DLPFC and dorsal caudate in children with ADHD children. Hypoconnectivity between VS and anterior prefrontal cortex correlated with increased emotional lability. |
| Costa Dias et al. 2013 | N = 99 with 35 ADHD children and 64 controls; 7-12 years. | Seed-based; (NAcc) | Medication washout of five-half lives | Hyperconnectivity between NAcc and anterior prefrontal cortex in ADHD children correlated with impulsivity as measured by delayed discounting. |
| An et al. 2013 | N = 55 with 23 ADHD boys and 32 controls; 8-15 years. | ReHo; voxelwise analysis | Medication discontinued one month before scan | Methylphenidate normalized ReHo in fronto-parieto-cerebellar regions. |
ADHD, attention-deficit/hyperactivity disorder; dACC, dorsal anterior cingulate cortex; DLPFC, dorsolateral prefrontal cortex; VS, ventral striatum; NAcc, nucleus accumbens; ReHo, regional homogeneity.