600 Differential Impact of Overnight Delta Power Dynamics on Neurocognition among Adolescents with ADHD versus Healthy Controls

Abstract

\n \n \n Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with neurocognitive impairment; however, mechanisms contributing to neurocognitive deficits in ADHD are poorly understood. Sleep disturbance is common in ADHD, and our previous work has shown associations between overnight delta power dynamics (lower initial delta peak, slower delta decline) and poorer neurocognition among individuals with insomnia, suggesting these processes may underlie sleep restoration. This study investigates relationships between delta power dynamics and neurocognition among adolescents with ADHD versus healthy controls (HC).\n \n \n \n In this ongoing study, 47 adolescents aged 13–17 (19 ADHD, 23 females, mean age=15.26) participated in a psychiatric evaluation and three nights of ambulatory polysomnography (PSG). Following the third night, participants completed the Cambridge Neuropsychological Test Automated Battery (CANTAB). Spectral analysis was conducted on a single O1-C3 channel and epochs were movement/artifact-free. Sleep variables were averaged over 3 nights. General linear models controlling for age, sex, total sleep time (TST), and wake after sleep onset (WASO) examined the effects of delta dynamics on neurocognition (summary score derived from principal components analysis of CANTAB subtests) and whether these associations differed across groups.\n \n \n \n PSG sleep variables did not differ by group (p’s>.05). Significant effects of group (F(7,36)=23.10, p<.0001), delta decline (F(7,36)=10.89, p=.002), and the group by delta decline interaction (F(7,36)=14.23, p=.0006) were observed. Results regarding initial delta peak showed a similar pattern, with a trend toward a main effect of initial delta peak (F(7,36)=3.53, p=.07) and a significant group by initial delta peak interaction effect (F(7,36)=9.91, p=.003) on neurocognition. Lower initial delta peak and slower delta decline were associated with poorer cognition among ADHD, but not HC, youth after covarying for age, sex, TST, and WASO.\n \n \n \n Overnight delta power dynamics may contribute to neurocognitive performance among adolescents with ADHD after accounting for sleep restriction and nighttime awakenings, highlighting the potential importance of sleep physiology in understanding neurocognitive deficits in this population. Future studies should identify whether there are phenotypic subgroups within ADHD characterized by disrupted overnight delta dynamics and examine whether insomnia treatments that impact delta decline (e.g., Cognitive-Behavioral Treatment—Insomnia) improve neurocognitive performance among adolescents with ADHD.\n \n \n \n This work was supported by K23MH108704 to Dr. Lunsford-Avery.\n