A longitudinal study conducted by the top neuroscientists in the field has concluded that the differences seen in the ADHD brain in childhood do not change when one reaches adulthood.
The findings published in the November 2011 issue of the Archives of General Psychiatry showed that the cortex was significantly thinner in the ADHD subjects than in comparison participants, both in the dorsal attentional network and in limbic areas. In addition, gray matter was significantly decreased in the ADHD subjects in the right caudate, right thalamus and bilateral cerebellar hemispheres.
Subjects with persistent ADHD did not differ significantly from those with remitting ADHD, the researchers found. Individuals with remitting ADHD had thicker cortex relative to those with persistent ADHD in the medial occipital cortex, insula, parahippocampus, and prefrontal regions, the researchers found.
“Anatomic gray matter reductions are observable in adults with childhood ADHD regardless of current diagnosis,’ the team wrote. “The most affected regions underpin top-down control of attention and regulation of emotion and motivation. Exploratory analyses suggest that diagnostic remission may result from compensatory maturation of prefrontal, cerebellar, and thalamic circuitry.”
The team of researchers included Xavier Castellaneos, Erika Proal, Philip Reiss, Rachel Klein, Salvatore Mannuzza and numerous others. They examined MRIs of the brains of 59 white boys aged 6 to 12, diagnosed with ADHD, and 80 others who were free of the condition at a research outpatient center.
The purpose of the study was to test whether adults with combined-type childhood ADHD exhibit cortical thinning and decreased gray matter in regions hypothesized to be related to ADHD, and to test whether anatomic differences are associated with a current ADHD diagnosis, including persistent vs remitting ADHD.
The team used whole-brain voxel-based morphometry and vertexwise cortical thickness analyses as their main outcome measures.
Erika Proal, PhD;Philip T. Reiss, PhD; Rachel G. Klein, PhD; Salvatore Mannuzza, PhD;Kristin Gotimer, MPH; Maria A. Ramos-Olazagasti, PhD; Jason P. Lerch, PhD; Yong He, PhD;Alex Zijdenbos, PhD; Clare Kelly, PhD; Michael P. Milham, MD, PhD; F. Xavier Castellanos, MD
Brain Gray Matter Deficits at 33-Year Follow-up in Adults With Attention-Deficit/Hyperactivity Disorder Established in Childhood
Arch Gen Psychiatry, Nov 2011; 68 (11) :1122-1134. doi: 10.1001/archgenpsychiatry.2011.117