The neuroanatomy of attention deficit hyperactivity disorder in adults: structural and functional neuroimaging findings

The objective of this work is to review the existing literature on findings from structural and functional magnetic resonance and connectivity. For a long time it was thought that children 'grew out' of attention deficit hyperactivity disorder (ADHD) on reaching adolescence. Yet, it is now known that up to 70% of children who present ADHD in childhood go on to present symptoms in the behavioural and cognitive sphere in adulthood. Neuroimaging studies conducted in adults with ADHD have shown alterations in the brain at the structural and functional levels, and also in terms of connectivity. These findings have been observed mainly in the inferior frontal and dorsolateral prefrontal cortex, as well as in striatal, anterior cingulate, parietotemporal and cerebellar regions. However, certain inconsistencies have also been found, which may be related with the presence of comorbidity, a history of medication, gender-related differences and the small size of the sample used in some studies. Differences have also been noted in relation to studies carried out in children with ADHD. Hence the importance for future studies of avoiding the existence of variables that can affect the findings in ADHD in adults and, moreover, of being able to determine whether the anatomical and functional deficits continue into adulthood.