"ADHD, Tic Disorder, Tourette's Syndrome, and Obsessive-Compulsive Disorder are all characterised by an impairment of executive
functioning and often occur together. There are thus indications of a similar neurobiological basis. This review presents an overview
of neuroimaging studies of these disorders in childhood and adolescence, focusing thereby on magnet resonance imaging data. Studies
provide concurring data about structural changes in the basal ganglia and the prefrontal cortex, and abnormal activation in the
fronto-striatal circuitry in patients as compared to healthy controls. ADHD and Tourette's Syndrome are both associated with prefrontal
aberrations. However, variances in Tourette's Syndrome are less pronounced, which might be due to compensation mechanisms.
ADHD children show small, but more global, morphological alterations in the cortex and cerebellum, while Tourette's Syndrome seems
to be linked additionally to differences in the occipital cortex. Furthermore, structural and functional data for obsessive-compulsive
disorder indicate aberrations in the amygdala and thalamus, and functional changes in the orbito-frontal cortex. By comparison,
findings in children with ADHD point towards abnormal activity in the ventral prefrontal cortex. To summarise, the data display an
impairment of cortico-striato-thalamic circuits which appears to be associated with dysfunctioning motor inhibition, and impulsive
behaviour and objectionable thoughts. Since the majority of the studies reviewed are characterised by small and heterogeneous samples,
and since the studies differ in their methods, comparability is limited and general conclusions can not be drawn."
This whole bunch of info tells us that ADHD children have changes in basal ganglia, prefrontal cortex as well as morphological changes
(morph means visually change and it was more global and smaller then for the others who where limited to changes in basal ganglia and
prefrontal cortex) in cortex and cerebellum. ADHD children also showed to have abnormal activity in the ventral prefrontal cortex.