Decreased sleep is linked longitudinally and directionally to alterations in the brain's intrinsic functional architecture, providing novel evidence that changes in sleep produce characteristic brain functional connectivity changes across adolescence.
Key Findings
Results
A robust and generalizable neurosignature of reduced sleep was identified in the ABCD dataset using connectome-based predictive modeling.
The neurosignature was derived from the Adolescent Brain Cognitive Development (ABCD) Study, a longitudinal observational study of 11,878 youth.
Connectome-based predictive modeling (CPM) was used to identify functional connectivity patterns associated with reduced sleep duration.
The neurosignature was described as 'robust and generalizable,' validated across independent subsets of participants.
The approach identified widespread changes in the brain's intrinsic functional architecture associated with reduced sleep.
Results
Greater reductions in sleep duration across two years were significantly related to greater expression of the reduced sleep neurosignature in an independent ABCD sample.
This finding was demonstrated longitudinally across a two-year period in an independent sample of ABCD participants.
The relationship was directional, linking changes in sleep duration over time to changes in brain functional connectivity.
This longitudinal analysis extends prior cross-sectional work by capturing within-person change over adolescent development.
The independent replication sample helped ensure the finding was not driven by overfitting in the original neurosignature derivation.
Results
Expression of the ABCD reduced sleep neurosignature was significantly increased within individuals following experimentally induced sleep deprivation in adults.
A second sample of 76 adult participants was scanned after a typical night of sleep and after a sleep deprivation causal manipulation.
Within-individual comparisons showed that sleep deprivation increased expression of the neurosignature derived from the adolescent ABCD sample.
This within-person experimental design provides directional (causal) evidence that reduced sleep produces brain connectivity changes, rather than connectivity changes causing reduced sleep.
The sleep deprivation manipulation constitutes a causal test, distinguishing the direction of the sleep-brain connectivity relationship.
Results
Neurosignatures of reduced sleep derived from the adolescent ABCD sample and the adult sleep deprivation sample exhibited significant spatial correspondence.
The spatial correspondence was demonstrated between the CPM-derived neurosignature from the ABCD youth dataset and the connectivity changes observed following sleep deprivation in the adult sample.
This cross-sample spatial correspondence suggests that the functional connectivity patterns linked to insufficient sleep are consistent across developmental stage (adolescents vs. adults) and study design (observational vs. experimental).
The convergence of findings across two independent and methodologically distinct samples strengthens confidence in the identified neurosignature.
The paper describes this as providing 'significant spatial correspondence' between the two samples' neurosignatures.
Background
Prior cross-sectional studies had demonstrated that reduced sleep is associated with widespread changes in the brain's intrinsic functional architecture, motivating the need for longitudinal and directional evidence.
The study explicitly frames itself as extending previous cross-sectional work.
Two key gaps addressed were the longitudinal nature of the sleep-brain relationship across adolescence and the directionality of this relationship.
The combination of a large observational longitudinal cohort (ABCD, n=11,878) with a causal manipulation experiment (n=76 adults) was described as a 'novel approach.'
Adolescence was identified as a critical period for examining sleep-brain relationships given ongoing neurodevelopment.
What This Means
This research suggests that getting less sleep actually causes measurable changes in how different regions of the brain communicate with each other — and that these effects are detectable both over years of adolescent development and within individuals after a single night of sleep deprivation. The researchers used data from nearly 12,000 adolescents tracked over two years, along with a separate experiment where 76 adults were scanned after normal sleep and after being kept awake, to build and test a 'brain signature' of reduced sleep.
A key strength of this study is that it addresses not just whether sleep and brain connectivity are related, but which comes first. By showing that experimentally depriving adults of sleep increases expression of the same brain signature found in adolescents who sleep less, the study provides evidence that reduced sleep is a cause — not just a consequence — of these brain changes. The brain signature was also consistent across the adolescent and adult samples, suggesting the effects of poor sleep on brain function may be a general phenomenon rather than specific to one age group.
This research matters because adolescence is a critical time for brain development, and many teenagers regularly sleep less than recommended amounts. These findings suggest that chronic short sleep during adolescence may not just be associated with poorer brain function — it may actively shape how the developing brain is organized. Understanding this relationship more precisely could inform public health efforts around sleep in young people.
Molloy M, Taxali A, Angstadt M, Toda-Thorne K, McCurry K, Weigard A, et al.. (2026). Decreased sleep is linked longitudinally and directionally to alterations in the brain's intrinsic functional architecture.. Developmental cognitive neuroscience. https://doi.org/10.1016/j.dcn.2025.101668