{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T11:51:43Z","timestamp":1776167503513,"version":"3.50.1"},"reference-count":49,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T00:00:00Z","timestamp":1776124800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Depressive symptoms have been linked to systemic inflammation, yet estimates in population-representative data vary by symptom severity and analytic specifications. We quantified the association between depressive symptom severity and high-sensitivity C-reactive protein (hs-CRP) in U.S. adults using design-based inference. Methods: We analysed pooled NHANES 2015\u20132018 data for adults aged \u2265 20 years (unweighted n = 9164; complete-case adjusted models n = 8173). Depressive symptom severity was categorised using the Patient Health Questionnaire-9 (PHQ-9) with 0\u20134 as the reference group and a pre-specified primary contrast of 10\u201314 versus 0\u20134. Outcomes were (i) continuous hs-CRP modelled on the log scale, reported as geometric mean ratios (GMR), and (ii) elevated inflammation defined as hs-CRP &gt; 3 mg\/L, modelled using a log-link to obtain prevalence ratios (PR). Models incorporated NHANES complex sampling and adjusted for a pre-specified core covariate set (age, sex, race\/ethnicity, education, poverty-income ratio, and smoking). Sensitivity analyses excluded hs-CRP &gt; 10 mg\/L and added BMI. Results: After adjustment, the geometric mean hs-CRP was 1.43 mg\/L (95% CI 1.21\u20131.70) for PHQ-9 0\u20134 and 1.63 mg\/L (95% CI 1.29\u20132.08) for PHQ-9 10\u201314. For the primary contrast (10\u201314 vs. 0\u20134), the adjusted GMR was 1.14 (0.96\u20131.35) and the PR was 1.15 (0.95\u20131.39). Using a clinically relevant dichotomy (PHQ-9 \u2265 10 vs. &lt;10), depressive symptoms were associated with higher hs-CRP (GMR 1.24 (1.07\u20131.43)) and a higher prevalence of hs-CRP &gt; 3 mg\/L (PR 1.19 (1.01\u20131.39)). Associations were strongest for PHQ-9 15\u201319 (GMR 1.62 (1.20\u20132.19); PR 1.49 (1.15\u20131.92)). In sensitivity analyses for the primary contrast, GMR estimates ranged from 1.01 to 1.14 and PR estimates ranged from 1.05 to 1.15, with attenuation towards the null after excluding hs-CRP &gt; 10 mg\/L and after additional adjustment for BMI. Conclusions: Higher depressive symptom severity was associated with higher hs-CRP and a higher prevalence of low-grade systemic inflammation in U.S. adults, with the clearest elevations observed among those with moderately severe symptoms. For the pre-specified moderate-symptom contrast, point estimates were modest and sensitive to handling of high hs-CRP values and adiposity-related adjustment.<\/jats:p>","DOI":"10.3390\/jcm15082975","type":"journal-article","created":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T10:29:08Z","timestamp":1776162548000},"page":"2975","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Associations of Depressive Symptom Severity with High-Sensitivity C-Reactive Protein Among U.S. Adults: NHANES 2015\u20132018"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2169-3208","authenticated-orcid":false,"given":"Diego","family":"Rivera-Porras","sequence":"first","affiliation":[{"name":"Universidad de la Costa, Departamento de Productividad e Innovaci\u00f3n, Barranquilla 080001, Atl\u00e1ntico, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Cepeda-Pineda","sequence":"additional","affiliation":[{"name":"Universidad de la Sabana, Facultad de Ciencias del Comportamiento, Ch\u00eda 250007, Cundinamarca, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sandra-Milena","family":"Carrillo-Sierra","sequence":"additional","affiliation":[{"name":"Universidad de Pamplona, Facultad de Psicolog\u00eda, Grupo de Investigaci\u00f3n Psicolog\u00eda y Sociedad, Pamplona 543050, Norte de Santander, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2348-2810","authenticated-orcid":false,"given":"Omar","family":"Rozo-P\u00e9rez","sequence":"additional","affiliation":[{"name":"Universidad Sim\u00f3n Bol\u00edvar, Facultad de Ciencias Jur\u00eddicas y Sociales, Centro de Investigaci\u00f3n en Estudios Fronterizos, C\u00facuta 540001, Norte de Santander, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Astrid","family":"Rozo-S\u00e1nchez","sequence":"additional","affiliation":[{"name":"Universidad de Pamplona, Facultad de Salud, Pamplona 543050, Norte de Santander, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1880-8887","authenticated-orcid":false,"given":"Valmore","family":"Berm\u00fadez","sequence":"additional","affiliation":[{"name":"Universidad Sim\u00f3n Bol\u00edvar, Centro de Investigaciones en Ciencias de la Vida, Barranquilla 080001, Atl\u00e1ntico, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,14]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2025). 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