Background: The dopaminergic system is thought to be essentially involved in the pathogenesis of attention deficit/hyperactivity disorder (ADHD). However, there is also evidence for abnormalities in the glutamatergic system and recent theories focus on a disturbed interaction between the two systems as the essential pathogenetic mechanism of ADHD. In the present study, we wanted to test the hypothesis that prefrontal glutamate signals indirectly indicate dopaminergic dysfunction in adult patients with ADHD.
Methods: Twenty-eight adult patients with ADHD and 28 group-matched healthy volunteers were studied clinically and using chemical-shift MR spectroscopy (MRS) of the prefrontal cortex covering the anterior cingulate gyrus.
Results: A significant reduction of the combined glutamate/glutamine to creatine ratio in the right anterior cingulate cortex in patients with ADHD was found.
Discussion: Glutamatergic alterations as measured with MRS might play a role in the pathogenesis of adult patients with ADHD.