The research stemmed from the lab's interest in olfaction, or the sense of smell. In mammals, the brain processes odor information during inhalation. This link between the brain and breathing led researchers to wonder: since every brain is unique, wouldn't each person's breathing pattern reflect that?

To test the idea, the team developed a lightweight wearable device that tracks nasal airflow continuously for 24 hours using soft tubes placed under the nostrils. Most breathing tests last just one to 20 minutes, focusing on evaluating lung function or diagnosing disease. But those brief snapshots aren't enough to capture subtle patterns.

"You would think that breathing has been measured and analyzed in every way," says author Noam Sobel of the Weizmann Institute of Science, Israel. "Yet we stumbled upon a completely new way to look at respiration. We consider this as a brain readout."

Sobel's team fitted 100 healthy young adults with the device and asked them to go about their daily lives. Using the collected data, the team identified individuals using only their breathing patterns with high accuracy. This high-level accuracy remained consistent across multiple retests conducted over a two-year period, rivaling the precision of some voice recognition technologies.

"I thought it would be really hard to identify someone because everyone is doing different things, like running, studying, or resting," says author Timna Soroka of the Weizmann Institute of Science. "But it turns out their breathing patterns were remarkably distinct."

Moreover, the study found that these respiratory fingerprints correlated with a person's body mass index, sleep-wake cycle, levels of depression and anxiety, and even behavioral traits. For example, participants who scored relatively higher on anxiety questionnaires had shorter inhales and more variability in the pauses between breaths during sleep. Soroka noted that none of the participants met clinical diagnostic criteria for mental or behavioral conditions. The results suggest that long-term nasal airflow monitoring may serve as a window into physical and emotional well-being.

"We intuitively assume that how depressed or anxious you are changes the way you breathe," says Sobel. "But it might be the other way around. Perhaps the way you breathe makes you anxious or depressed. If that's true, we might be able to change the way you breathe to change those conditions."

The current device still faces real-world challenges. A tube that runs under the nose is often associated with illness and may deter adoption. The device also doesn't account for mouth breathing and can slip out of place when sleeping. The team aims to design a more discreet and comfortable version for everyday use.

Soroka and Sobel are already investigating whether people can mimic healthy breathing patterns to improve their mental and emotional states. "We definitely want to go beyond diagnostics to treatment, and we are cautiously optimistic," says Sobel.

Results show that teens who got up to two more hours of sleep on weekends than on weekdays exhibited fewer anxiety symptoms compared with those who did not sleep longer on weekends. However, longer durations of catch-up sleep on weekends were associated with slightly more internalizing symptoms.

"The results show that both sleeping less on weekends than weekdays and sleeping substantially more on weekends were associated with higher anxiety symptoms," said lead author Sojeong Kim, a doctoral candidate in the department of clinical psychology and psychology graduate advisor at the University of Oregon in Eugene. "In contrast, moderate catch-up sleep -- defined as less than two hours -- was associated with lower anxiety symptoms, suggesting that some weekend recovery sleep may be beneficial."

The American Academy of Sleep Medicine recommends that teenagers 13 to 18 years of age should sleep 8 to 10 hours on a regular basis to promote optimal health. However, CDC data show that only 23% of high school students get sufficient sleep on an average school night.

"Many teens try to make up for lost sleep by sleeping in on weekends," Kim said.

Consistently getting sufficient sleep is associated with better health outcomes including improved attention, behavior, learning, memory, emotional regulation, quality of life, and mental and physical health. In contrast, insufficient sleep in teenagers is associated with increased risks of problems such as depression and suicidal thoughts.

The study involved 1,877 adolescents with a mean age of 13.5 years. Sleep duration was estimated using Fitbit devices, while internalizing symptoms were assessed using the Child Behavior Checklist survey. Weekend catch-up sleep was calculated as the difference between weekend and weekday sleep duration.

Kim noted that it is important to identify the right amount of catch-up sleep that is beneficial to teens who restrict their sleep during the week.

"Too little or too much sleep variability from weekday to weekend may contribute to the symptoms someone is trying to combat, like physical or mental fatigue and feelings of anxiety," she said.

The research abstract was published recently in an online supplement of the journal Sleep and will be presented Wednesday, June 11, during SLEEP 2025 in Seattle. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

Abstract Title: The Sweet Spot of Weekend Catch-Up Sleep: A Protective Factor Against Depressive Symptoms?

Abstract ID: 0263

The study, partly funded by the National Institutes of Health, was published May 22 in Cancer Discovery.

Investigators were surprised they could detect cancer-derived mutations in the blood so much earlier, says lead study author Yuxuan Wang, M.D., Ph.D., an assistant professor of oncology at the Johns Hopkins University School of Medicine. "Three years earlier provides time for intervention. The tumors are likely to be much less advanced and more likely to be curable."

To determine how early cancers could be detected prior to clinical signs or symptoms, Wang and colleagues assessed plasma samples that were collected for the Atherosclerosis Risk in Communities (ARIC) study, a large National Institutes of Health-funded study to investigate risk factors for heart attack, stroke, heart failure and other cardiovascular diseases. They used highly accurate and sensitive sequencing techniques to analyze blood samples from 26 participants in the ARIC study who were diagnosed with cancer within six months after sample collection, and 26 from similar participants who were not diagnosed with cancer.

At the time of blood sample collection, eight of these 52 participants scored positively on a multicancer early detection (MCED) laboratory test. All eight were diagnosed within four months following blood collection. For six of the eight individuals, investigators also were able to assess additional blood samples collected 3.1-3.5 years prior to diagnosis, and in four of these cases, tumor-derived mutations could also be identified in samples taken at the earlier timepoint.

"This study shows the promise of MCED tests in detecting cancers very early, and sets the benchmark sensitivities required for their success," says Bert Vogelstein, M.D., Clayton Professor of Oncology, co-director of the Ludwig Center at Johns Hopkins and a senior author on the study.

"Detecting cancers years before their clinical diagnosis could help provide management with a more favorable outcome," adds Nickolas Papadopoulos, Ph.D., professor of oncology, Ludwig Center investigator and senior author of the study. "Of course, we need to determine the appropriate clinical follow-up after a positive test for such cancers."

The study was supported in part by National Institutes of Health grant #s R21NS113016, RA37CA230400, U01CA230691, P30 CA 06973, DRP 80057309, and U01 CA164975. Additional funding was provided by the Virginia and D.K. Ludwig Fund for Cancer Research, the Commonwealth Fund, the Thomas M Hohman Memorial Cancer Research Fund, The Sol Goldman Sequencing Facility at Johns Hopkins, The Conrad R. Hilton Foundation, the Benjamin Baker Endowment, Swim Across America, Burroughs Wellcome Career Award for Medical Scientists, Conquer Cancer -- Fred J. Ansfield, MD, Endowed Young Investigator Award, and The V Foundation for Cancer Research. The Atherosclerosis Risk in Communities study has been funded in whole or in part with federal funds from the National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, under contract numbers 75N92022D00001, 75N92022D00002, 75N92022D00003, 75N92022D00004, and 75N92022D00005.