{
  "abstract": "Adolescence is a sensitive developmental period marked by increased reactivity of the HPA axis to environmental stressors. However, little is known about how chronic cortisol levels change during prolonged adversity. Using the COVID-19 pandemic as a natural experiment, this study examines how large-scale environmental disruption affects HPA-axis regulation during adolescence. We investigated hair cortisol concentration (HCC) pre- and during the pandemic in adolescents from Pelotas, Brazil, and identified predictors for change. Data were drawn from the 2004 Pelotas Birth Cohort, a population-based longitudinal study. Hair samples (3 cm) were collected at the 15-year pre-pandemic assessment (T1; 2019–2020) and again at the 17-year mid-pandemic assessment (T2; 2021). HCC was quantified via ELISA method. Socioeconomic, demographic, and pandemic-related experiences, as well as self-reported stress levels, were assessed as potential determinants of changes in HCC. A multivariate latent change score (LCS) model was used to analyze changes in HCC and their associations with predictors. A total of 1,509 individuals were included in the analyses. There was a significant mean increase in HCC of 1.89 pg/mg ( p < 0.001) from T1 to T2. Pandemic-related experiences, such as maternal job loss ( p = 0.005) and higher levels of perceived stress ( p = 0.041), were associated with greater increases in HCC. Government cash transfer program participation ( p < 0.001), having a black or mixed-race mother ( p = 0.017), and being female ( p < 0.001) were associated with lower increases in HCC. Findings suggest significant physiological effects of the COVID-19 pandemic, highlighting the role of demographic, socioeconomic, and pandemic-related factors in shaping cortisol responses and advancing understanding of its impact on adolescent health, with implications for policy and support in low- and middle-income countries. These findings highlight the intricate relationship between cortisol changes and psychological outcomes across various populations during the pandemic.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 11,
  "authors": [
    {
      "name": "Luciana Tovo-Rodrigues"
    },
    {
      "name": "Marina Xavier Carpena"
    },
    {
      "name": "Jessica Mayumi Maruyama"
    },
    {
      "name": "Andrea Gonzalez"
    },
    {
      "name": "Aluisio J.D. Barros"
    },
    {
      "name": "Iná S. Santos"
    },
    {
      "name": "Isabel Oliveira"
    },
    {
      "name": "Alexia Tormen"
    },
    {
      "name": "Jaqueline Bohrer Schuch"
    },
    {
      "name": "Alicia Matijasevich"
    },
    {
      "name": "Joseph Murray"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/82sq0grjtdz6x.bib",
  "cited_by": 0,
  "doi": "10.1038/s41598-026-74526-z",
  "fulltext_url": null,
  "id": "82sq0grjtdz6x",
  "issns": [
    "2045-2322"
  ],
  "landing_url": "https://www.nature.com/articles/s41598-026-74526-z",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2802|Stress Responses and Cortisol"
    ]
  ],
  "openalex": "W7161011199",
  "pdf_url": "https://www.nature.com/articles/s41598-026-74526-z_reference.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": "Springer Science and Business Media LLC",
  "ris": "https://research.draconitic.com/paper/82sq0grjtdz6x.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:25Z",
      "native_id": "10.1038/s41598-026-74526-z",
      "source": "crossref",
      "url": "https://www.nature.com/articles/s41598-026-74526-z"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2802|Stress Responses and Cortisol",
      "subfield": "neuroscience"
    }
  ],
  "title": "Changes in hair cortisol among Brazilian adolescents before and during the COVID-19 pandemic",
  "title_text": "Changes in hair cortisol among Brazilian adolescents before and during the COVID-19 pandemic",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:25Z",
  "url": "https://research.draconitic.com/paper/82sq0grjtdz6x",
  "venue": "Scientific Reports",
  "versions": []
}