Anxiety severity moderates the relation between pineal parenchymal volume and objective sleep problems in peri-adolescent youth, whereby elevated anxiety was associated with larger pineal parenchymal volume and longer sleep onset latency, reduced sleep efficiency, and reduced NREM duration.
Key Findings
Results
Significant interactions were found between anxiety severity and pineal parenchymal volume (PPV) on sleep onset latency (SOL), sleep efficiency (SE), and NREM duration, but not REM duration.
Linear models were used to assess the interaction between anxiety severity and PPV on sleep outcomes derived from polysomnography.
Elevated anxiety was associated with larger PPV and longer SOL and reduced SE and NREM duration.
No significant interaction was found between anxiety severity and PPV on REM duration.
The sample used for these analyses was n = 135 participants with both structural scan and polysomnography data.
Methods
The study sample consisted of peri-adolescent youth aged 10–13 years sampled across a continuum of anxiety severity with special emphasis on social, generalized, and separation anxiety disorders.
Total sample was N = 200 youth aged 10–13 years.
The study emphasized social anxiety, generalized anxiety, and separation anxiety disorders to capture variability in key risk profiles and behaviors.
Participants were sampled across a continuum of anxiety severity rather than a binary clinical/non-clinical grouping.
A subset of n = 135 participants had both structural MRI and polysomnography data available for analyses.
Methods
Pineal glands were manually segmented into parenchymal and cyst compartments, distinguishing pineal parenchymal volume from cystic components.
Manual segmentation was applied to structural MRI scans to separate parenchymal tissue from cyst tissue within the pineal gland.
The study specifically examined pineal parenchymal volume (PPV) rather than total pineal gland volume, allowing differentiation of functionally relevant tissue.
The pineal gland was selected as a target given its role in sleep behavior and associations with multiple disorders that report problems with sleep.
Results
Elevated anxiety severity was associated with larger pineal parenchymal volume in peri-adolescent youth.
The direction of the interaction indicated that higher anxiety was linked to greater PPV.
This relationship was observed specifically in the context of sleep outcome measures including SOL, SE, and NREM duration.
The authors note that peri-adolescence is a period when anxiety symptoms escalate and sleep changes occur concurrently.
Conclusions
The authors conclude that pineal morphology may be a contributing factor to sleep problems in anxiety during peri-adolescence.
The pineal gland's role in melatonin production and sleep regulation underpins its candidacy as a relevant structure in anxiety-related sleep disturbances.
The study framed peri-adolescence as a critical developmental window given escalating anxiety symptoms and sleep changes during this period.
Results suggest that structural variation in the pineal gland, specifically its parenchymal compartment, may interact with anxiety to worsen objective sleep outcomes.
What This Means
This research suggests that the size of a specific brain structure called the pineal gland — and particularly its active tissue component (the parenchyma) — is linked to sleep problems in anxious preteens and early adolescents. Using brain scans and overnight sleep monitoring (polysomnography) in 135 youth aged 10–13, the researchers found that kids with higher anxiety levels who also had larger pineal parenchymal volumes took longer to fall asleep, slept less efficiently, and spent less time in deep (non-REM) sleep. Importantly, the relationship between pineal gland size and sleep was different depending on how anxious a child was — meaning anxiety 'moderated' the connection between brain structure and sleep.
The pineal gland produces melatonin, the hormone that helps regulate sleep timing, making it a biologically plausible target for understanding why anxious youth struggle with sleep. The researchers carefully separated the pineal gland's functional tissue from any fluid-filled cysts that can naturally occur within it, allowing a more precise look at the tissue most relevant to sleep regulation. This level of detail distinguishes the study from prior work that treated the pineal gland as a single structure.
This research matters because sleep problems and anxiety are both very common during the transition to adolescence, and they often worsen each other. Identifying a biological marker — in this case, pineal parenchymal volume — that appears to interact with anxiety to produce worse sleep could eventually help researchers understand who is most at risk and why. This is an early-stage finding focused on understanding mechanisms rather than clinical application, but it opens a door to investigating whether pineal gland structure plays a role in the well-known link between anxiety and poor sleep in young people.
Fuertes F, Lalama M, Dick A, Baker A, McMakin D, Mattfeld A. (2026). Anxiety severity moderates the relation between pineal parenchymal volume and objective sleep problems in peri-adolescent youth.. Scientific reports. https://doi.org/10.1038/s41598-026-39349-y