# Circadian rhythms and homeostatic sleep regulation during adolescence: Implications for reward, cognitive control, and substance use risk

> **NIH NIH P50** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2021 · $530,713

## Abstract

PROJECT SUMMARY PROJECT 1 (P1)
Substance use disorders (SUD) are widely prevalent and pose devastating health, financial, and societal costs.
The incidence of SU increases across adolescence, making this sensitive developmental period one of both
heightened risk and heightened opportunity for prevention and intervention. However, to develop effective
interventions, we need to identify novel and modifiable risk factors and mechanisms for SUD. Circadian rhythm
and sleep disturbances have strong ties to SU risk, and their effects on intermediary markers of SU risk in
adolescence—reward and inhibitory control systems—provides a plausible mechanistic substrate. The Center’s
conceptual model posits that adolescent development is associated with enhanced reward function relative to
cognitive control, phase delay in endogenous circadian rhythms, and lower homeostatic sleep drive.
Environmental and social factors interact with these developmental processes, often resulting in late sleep
timing, short sleep duration, and circadian misalignment—each of which is associated with increased substance
use in teens and young adults. P1 will utilize the constant routine paradigm to rigorously characterize circadian
rhythms and homeostatic sleep drive by controlling for masking influences of physical activity, posture, meals,
and light levels. We will examine their individual and combined effects on measures of reward and cognitive
control, and in combination with P2, on the development of substance use, to test the underlying mechanisms
involved in the CARRS conceptual model. P1 will enroll 96 adolescents ages 13–15 (50% female) stratified by
habitual sleep timing (early, intermediate, late, N=32 each). Participants will monitor sleep patterns at home with
actigraphy and sleep diary, then complete fMRI measures of reward and cognitive control and a 60-hour lab
session. The lab session includes two nights of polysomnographic (PSG) sleep studies, separated by 36 hours
of sleep deprivation. After the first PSG, participants will follow a constant routine for the next 24 hours with
wakeful bedrest; semi-recumbent posture; constant dim light; and hourly nutritional supplements. After 24 hours,
participants will remain awake, but not confined to bed. Physiological circadian measures include salivary
melatonin; core body temperature; and molecular rhythms from hair follicle cells (examined in P3). Physiological
sleep homeostatic measures include waking EEG theta power. and delta sleep EEG response following 36 hours
of wakefulness. Behavioral tests indexing cognitive control performance with and without reward modulation
along with self-reports of mood and sleepiness will be collected every 2 hours. Finally, online surveys will index
substance use every 6 months through study conclusion. P1 will draw directly on resources provided by the
Center Cores. CARRS and P1 will innovatively advance understanding of distinct circadian and sleep
homeostatic effects on reward-cognit...

## Key facts

- **NIH application ID:** 10217070
- **Project number:** 5P50DA046346-02
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** PETER L FRANZEN
- **Activity code:** P50 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $530,713
- **Award type:** 5
- **Project period:** 2020-07-15 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10217070

## Citation

> US National Institutes of Health, RePORTER application 10217070, Circadian rhythms and homeostatic sleep regulation during adolescence: Implications for reward, cognitive control, and substance use risk (5P50DA046346-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10217070. Licensed CC0.

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