A neurophysiological marker of impaired preparation in an 11-year follow-up study of attention-deficit/hyperactivity disorder (ADHD).
BACKGROUND
This longitudinal electrophysiological study investigated the course of multiple impaired cognitive brain functions in attention-deficit/hyperactivity disorder (ADHD) from childhood to adulthood by comparing developmental trajectories of individuals with ADHD and typically developing controls.


METHODS
Subjects with ADHD (N = 11) and normal controls (N = 12) diagnosed in childhood [mean age ADHD/CTRL = 10.9 years [SD 1.72]/10.0 years (SD 1.03)] were followed up after 1.1 and 2.4 years, and as young adults [ADHD/CTRL: 21.9 years (SD 1.46)/21.1 years (SD 1.29)]. At all four times, event-related potential (ERP) maps were recorded during a cued continuous performance test (CPT). We focused on residual deficits as adults, and on developmental trajectories (time and time × group effects) for CPT performance and attentional (Cue P300), preparatory (CNV: contingent negative variation) and inhibitory (NoGo P300) ERP components.


RESULTS
All ERP components developed without significant time × group interactions. Only the CNV remained reduced in the ADHD group, although 8/11 individuals no longer met a full ADHD diagnosis as adults. Cue P300 and NoGo P300 group differences became nonsignificant in early adulthood. The CNV parameters correlated with reaction time (RT) and RT-SD. Perceptual sensitivity improved and the groups' trajectories converged with development, while RT-SD continued to be elevated in adult ADHD subjects.


CONCLUSIONS
Attentional and preparatory deficits in ADHD continue into adulthood, and the attenuated CNV appears to reflect a particularly stable ADHD marker. Although some deficit reductions may have gone undetected due to small sample size, the findings challenge those developmental lag models postulating that most ADHD-related deficits become negligible with brain maturation.
Department of Child and Adolescent Psychiatry, University of Zurich, Zurich, Switzerland. mirko.doehnert@uniklinikleipzig.de
Mirko
M
Doehnert
Daniel
D
Brandeis
Gudrun
G
Schneider
Renate
R
Drechsler
Hans-Christoph
HC
Steinhausen
D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D003265:Contingent Negative Variation / Q000502:physiology*; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D013997:Time Factors; D055815:Young Adult