Misinterpreting emotional expressions in attention-deficit/hyperactivity disorder: evidence for a neural marker and stimulant effects.
BACKGROUND
In addition to cognitive impairment, there are disruptions to mood and emotion processing in attention-deficit/hyperactivity disorder (ADHD) but little is known about their neural basis. We examined ADHD disturbances in mood and emotion recognition and underlying neural systems before and after treatment with stimulant medication.


METHODS
Participants were 51 unmedicated ADHD adolescents and 51 matched healthy control subjects rated for depressed and anxious mood and accuracy for identifying facial expressions of basic emotion. Brain function was recorded using event-related potentials (ERPs) while subjects viewed these expressions. ADHD subjects were retested after 4 weeks, following treatment with methylphenidate (MPH).


RESULTS
ADHD subjects showed a profile of emotion-related impairment: higher depression and anxiety, deficits in identifying threat-related emotional expressions in particular, and alterations in ERPs. There was a pronounced reduction in occipital activity during the early perceptual analysis of emotional expression (within 120 msec), followed by an exaggeration of activity associated with structural encoding (120-220 msec) and subsequent reduction and slowing of temporal brain activity subserving context processing (300-400 msec). Methylphenidate normalized neural activity and produced some improvement of emotion recognition but had no impact on negative mood. Improvements in neural activity with MPH were consistent predictors of improvement in clinical features of emotional lability and hyperactivity.


CONCLUSIONS
Objective behavioral and brain function measures of emotion processing may provide a valuable addition to the clinical armamentarium for assessing emotional disturbances in ADHD and the efficacy of stimulants for treating these disturbances.
Williams
Leanne M
LM
Brain Dynamics Centre and Clinics, Westmead Millennium Institute & Western Clinical School, University of Sydney, Westmead Hospital, New South Wales, Australia. lea_williams@wmi.usyd.edu.au
Hermens
Daniel F
DF
Palmer
Donna
D
Kohn
Michael
M
Clarke
Simon
S
Keage
Hannah
H
Clark
C Richard
CR
Gordon
Evian
E
D000293:Adolescent; D001007:Anxiety / Q000503:physiopathology; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D003863:Depression / Q000503:physiopathology; D004569:Electroencephalography; D004644:Emotions; D005074:Evoked Potentials, Visual / Q000187:drug effects / Q000502:physiology; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D010364:Pattern Recognition, Visual / Q000187:drug effects / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods
D000697:Central Nervous System Stimulants; D008774:Methylphenidate