{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T06:15:40Z","timestamp":1788156940218,"version":"build-2803163510"},"reference-count":32,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T00:00:00Z","timestamp":1788134400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pediatr."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Elexacaftor\/tezacaftor\/ivacaftor (ETI) sustainably improves lung function (FEV\u2081), quality of life and sweat chloride (SC) levels in people with cystic fibrosis (pwCF). Psychological comorbidities may impair treatment adherence. This study assessed ETI adherence using SC and medication possession ratio (MPR) and evaluated the impact of depressive symptoms.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>In this retrospective observational study, 34 pwCF aged 12\u201321 years (median 17.3) initiating ETI between 2020 and 2022 were included. SC and FEV\u2081 were measured at baseline and annually over four years. Depressive symptoms were screened annually using the PHQ-9 (score \u22657). Adherence was assessed by MPR (1.0\u2009=\u2009full medication supply). Patients with prior CFTR modulator therapy, insulin-dependent diabetes or organ transplantation were excluded.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Fifteen pwCF (44.1%) screened positive for depressive symptoms (mean PHQ-9 scores 11 vs. 2). Median SC decreased significantly from 102.5\u2005mmol\/L (98\u2013106.5) at baseline to 46.5\u2005mmol\/L (32.5\u201357.8) in year 1 (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&amp;lt;\u20090.001) and remained stable thereafter. PwCF with depressive symptoms demonstrated greater SC variability during follow-up, with a trend toward higher SC levels at follow-up visit 4 (between-group\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.056), while the within-group increase from FV1 to FV4 was significant (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.012)., MPR declined significantly from 0.95 to 0.75 (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&amp;lt;\u20090.05). FEV\n                      <jats:sub>1<\/jats:sub>\n                      improved significantly in year 1 compared to baseline (+11%,\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&amp;lt;\u20090.001) and remained stable in both groups.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>ETI leads to sustained improvements in lung function and sweat chloride in pwCF. A substantial proportion of patients screened positive for depressive symptoms, which was associated with increased long-term variability in sweat chloride and declining MPR but not lung function. Structured psychological monitoring and targeted interventions may be essential to support adherence and long-term treatment success.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fped.2026.1888421","type":"journal-article","created":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T05:40:12Z","timestamp":1788154812000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Association of depressive symptoms with sweat chloride variability and medication possession ratio during long-term Elexacaftor\/Tezacaftor\/Ivacaftor therapy in adolescents and young adults with cystic fibrosis"],"prefix":"10.3389","volume":"14","author":[{"given":"Michael","family":"Lorenz","sequence":"first","affiliation":[{"name":"Cystic Fibrosis Centre, Department of Paediatrics, Jena University Hospital, Friedrich-Schiller-University","place":["Jena, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariya","family":"Pavlova","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Centre, Department of Paediatrics, Jena University Hospital, Friedrich-Schiller-University","place":["Jena, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katja","family":"Erler","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Centre, Department of Paediatrics, Jena University Hospital, Friedrich-Schiller-University","place":["Jena, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anika","family":"Nader","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Centre, Department of Paediatrics, Jena University Hospital, Friedrich-Schiller-University","place":["Jena, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne","family":"Moeser","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Centre, Department of Paediatrics, Jena University Hospital, Friedrich-Schiller-University","place":["Jena, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,31]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"CD013766","DOI":"10.1002\/14651858.CD013766.pub2","article-title":"Psychological interventions for improving adherence to inhaled therapies in people with cystic fibrosis","volume":"3","author":"Dawson","year":"2023","journal-title":"Cochrane Database Syst Rev"},{"key":"B2","doi-asserted-by":"publisher","first-page":"240060","DOI":"10.1183\/16000617.0060-2024","article-title":"Medication adherence to CFTR modulators in patients with cystic fibrosis: a systematic review","volume":"33","author":"Hansen","year":"2024","journal-title":"Eur Respir Rev"},{"key":"B3","doi-asserted-by":"publisher","first-page":"142","DOI":"10.1378\/chest.13-1926","article-title":"Pulmonary medication adherence and health-care use in cystic fibrosis","volume":"146","author":"Quittner","year":"2014","journal-title":"Chest"},{"key":"B4","doi-asserted-by":"publisher","first-page":"357","DOI":"10.1111\/bjhp.12357","article-title":"Adherence to medication in adults with cystic fibrosis: an investigation using objective adherence data and the theoretical domains framework","volume":"24","author":"Arden","year":"2019","journal-title":"Br J Health Psychol"},{"key":"B5","doi-asserted-by":"publisher","first-page":"1731","DOI":"10.4187\/respcare.02990","article-title":"Adherence of subjects with cystic fibrosis to their home program: a systematic review","volume":"59","author":"O'Donohoe","year":"2014","journal-title":"Respir Care"},{"key":"B6","doi-asserted-by":"publisher","first-page":"1940","DOI":"10.1016\/S0140-6736(19)32597-8","article-title":"VX17-445-103 Trial group. 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