Quantitative EEG analysis in dexamphetamine-responsive adults with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (AD/HD) is recognized as a disorder affecting children and adolescents and has more recently been documented to continue into adulthood in a proportion of patients. One of the common treatments for AD/HD is the use of stimulant medications. Numerous studies have examined the therapeutic effects of stimulant medications in children, adolescents and adults with the disorder, reporting improvements in attention, concentration, and hyperactive and impulsive behaviours. Several studies have also examined the effects of stimulants on the electroencephalograph (EEG) of children and adolescents with the disorder, but to date, there have been no studies examining the effects of stimulant medication on the EEG of adults with AD/HD. In the present study, we aimed to replicate previous EEG findings in adults with AD/HD relative to controls and to examine whether there was any change in this profile following treatment with dexamphetamine. The EEG was recorded at rest in an eyes-open condition from 50 adults diagnosed with AD/HD and assessed as good responders to treatment, both before and after treatment with dexamphetamine, and 50 control subjects. The pre-medication results are similar to those found in previous research that compared the EEGs of adults with AD/HD and control subjects. Following medication, there was a significant reduction in slow wave activity in the AD/HD group to levels similar to those in the control group. These results suggest that changes in brain function of good responders to dexamphetamine, as reflected in the EEG, may underlie the behavioural improvements observed in the clinical setting.