The last two decades of modern imaging techniques applied to research into attention deficit hyperactivity disorder (ADHD) have substantially expanded our knowledge of the underlying neural substrates of this condition and have shed light on the mechanism of action of the most common treatment of the disorder, stimulant medication. Studies have shown that ADHD is a multisystem disorder affecting several late developing fronto-cortical and fronto-subcortical pathways that mediate mature adult behaviour and cognition. Psychostimulants appear to modulate brain catecholamines and to have a normalising impact on some of the brain deficits in ADHD. The challenge lies in finding avenues to use neuroimaging techniques in clinical practice to aid diagnosis, treatment and prediction of response to treatment of ADHD.
Keywords: ADHD, fMRI, MRI, methylphenidate, psychostimulant medication, frontal lobes, basal ganglia, cerebellum, parieto-temporal regions