ADHD has been associated with cortico-striatal dysfunction that may lead to procedural memory abnormalities. Sleep plays a critical role in consolidating procedural memories, and sleep problems are an integral part of the psychopathology of ADHD. This raises the possibility that altered sleep processes characterizing those with ADHD could contribute to their skill-learning impairments. On this basis, the present study tested the hypothesis that young adults with ADHD have altered sleep-dependent procedural memory consolidation. Participants with ADHD and neurotypicals were trained on a visual discrimination task that has been shown to benefit from sleep. Half of the participants were tested after a 12-h break that included nocturnal sleep (sleep condition), whereas the other half were tested after a 12-h daytime break that did not include sleep (wakefulness condition) to assess the specific contribution of sleep to improvement in task performance. Despite having a similar degree of initial learning, participants with ADHD did not improve in the visual discrimination task following a sleep interval compared to neurotypicals, while they were on par with neurotypicals during the wakefulness condition. These findings represent the first demonstration of a failure in sleep-dependent consolidation of procedural learning in young adults with ADHD. Such a failure is likely to disrupt automatic control routines that are normally provided by the non-declarative memory system, thereby increasing the load on attentional resources of individuals with ADHD.
Bibliographical noteFunding Information:
This research was supported by a grant from the Israel Science Foundation (grant no. 734/22) and the National Institute of Psychobiology in Israel awarded to Yafit Gabay and by the Binational Scientific Foundation (grant no. 2015227) and the National Science Foundation-Binational Scientific Foundation (BSF2016867, NSF BCS1655126) grants awarded to Yafit Gabay and Lori Holt, respectively. This study is part of the research conducted at the University of Haifa by Ranin Ballan, as partial fulfillment of her requirements for a PhD degree under the supervision of Yafit Gabay.
© 2022, The Author(s).
ASJC Scopus subject areas
- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Biological Psychiatry