 In children with ADHD , there is a general reduction of volume in certain brain structures , with a proportionally greater decrease in the volume in the left @-@ sided prefrontal cortex . The posterior parietal cortex also shows thinning in ADHD individuals compared to controls . Other brain structures in the prefrontal @-@ striatal @-@ cerebellar and prefrontal @-@ striatal @-@ thalamic circuits have also been found to differ between people with and without ADHD . 
