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Case Control Study
©Author(s) (or their employer(s)) 2026. No commercial re-use. See Permissions. Published by Baishideng Publishing Group Inc.
World J Clin Pediatr. Mar 9, 2026; 15(1): 115246
Published online Mar 9, 2026. doi: 10.5409/wjcp.v15.i1.115246
Could high serum C-reactive protein levels serve as a biomarker for children and adolescents diagnosed with generalized anxiety disorder?
Kübranur Ünal, Yasemin Taş Torun, Mehmet Emre Erol, Zeynep Kübra Kurt, Cansu Özbaş
Kübranur Ünal, Department of Medical Biochemistry, Faculty of Medicine, Gazi University, Ankara 06560, Türkiye
Yasemin Taş Torun, Department of Child and Adolescent Mental Health and Diseases, Faculty of Medicine, Gazi University, Ankara 06560, Türkiye
Mehmet Emre Erol, Department of Medical Biochemistry, Institute of Health Sciences, Gazi University, Ankara 06560, Türkiye
Zeynep Kübra Kurt, Child Adolescent Psychiatric Clinic, Ankara Etlik City Hospital, Ankara 06170, Türkiye
Cansu Özbaş, Department of Public Health, Faculty of Medicine, Gazi University, Ankara 06560, Türkiye
Author contributions: Ünal K, Taş Torun Y, and Kurt ZK contributed to material preparation and data collection; Ünal K and Taş Torun Y contributed to supervision; Ünal K and Erol ME contributed to literature review; Ünal K and Erol ME contributed to data interpretation and writing - original draft; Ünal K and Kurt ZK contributed to conceptualization and study design; Özbaş C contributed to data analysis. All authors participated in the review and editing of the manuscript and provided final approval for the version to be published.
Institutional review board statement: The current study was conducted per the ethical principles of the Declaration of Helsinki. This retrospective study was approved by the Ethics Committee of Gazi University.
Informed consent statement: Written informed consent was obtained from all participants and/or their parents/legal guardians prior to enrollment.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Data sharing statement: De-identified datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.
Corresponding author: Kübranur Ünal, MD, Associate Professor, Department of Medical Biochemistry, Faculty of Medicine, Gazi University, Emniyet Mahallesi, Bandırma Caddesi, Ankara 06560, Türkiye. kubranurunal@gazi.edu.tr
Received: October 14, 2025
Revised: October 28, 2025
Accepted: January 6, 2026
Published online: March 9, 2026
Processing time: 145 Days and 12.3 Hours
Abstract
BACKGROUND

Generalized anxiety disorder (GAD) is a prevalent psychiatric condition in children and adolescents, frequently linked to difficulties in daily functioning and academic performance. Increasing evidence suggests that immune dysregulation and neuroinflammatory pathways contribute to its pathophysiology, yet studies examining circulating cytokines and related biomarkers in pediatric populations are still scarce.

AIM

To investigate serum levels of C-reactive protein (CRP), tumor necrosis factor-like weak inducer of apoptosis, neopterin, interleukin-6, tumor necrosis factor-alpha, interferon-gamma, and zinc in drug-naïve children and adolescents with GAD, to gain insight into potential immune-related alterations.

METHODS

The observational case-control design was conducted, including 25 drug-naïve patients with ‘pure’ GAD and 30 healthy controls aged 8-18 years. Psychiatric diagnoses were confirmed by the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version, Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and the Revised Child Anxiety and Depression Scale. Venous blood samples were analyzed using enzyme-linked immunosorbent assay, nephelometry, and electro-chemiluminescence assays. Group comparisons were performed using the Mann-Whitney U test and the χ2 test, and correlations were assessed using Spearman's correlation.

RESULTS

CRP levels were significantly higher in the GAD group than controls (median 1.7 mg/L vs 1.3 mg/L, P = 0.034, r = 0.32). No significant group differences were observed for tumor necrosis factor-alpha tumor necrosis factor-like weak inducer of apoptosis, interleukin-6, interferon-gamma, zinc, or neopterin. Time since symptom onset was positively correlated with total anxiety severity (r = 0.729, P = 0.001). Receiver operating characteristic analysis showed modest diagnostic value for CRP (area under the curve = 0.665, 95% confidence interval: 0.511-0.820).

CONCLUSION

This study demonstrates a moderate elevation in CRP levels in drug-naïve patients with GAD. Although no change in other inflammatory markers was observed in our study, this may suggest a low-grade inflammatory response. The early detection of symptoms is still critical, and more longitudinal studies with larger samples are necessary further to elucidate the role of inflammation in childhood anxiety pathophysiology.

Keywords: C-reactive protein; Cytokines; Generalized anxiety disorder; Psychiatric; Biomarker; Inflammation

Core Tip: This study investigated the potential relationship between generalized anxiety disorder (GAD) and systemic inflammation in drug-naïve children and adolescents. Significantly higher C-reactive protein levels compared to healthy controls suggest a low-grade inflammatory process may be present in pediatric GAD. In contrast, no significant group differences were found in other circulatory immune markers. This selective pattern of elevation suggests that specific components of the inflammatory response may be activated in a limited manner in GAD. Furthermore, the positive correlation between clinical symptom severity and illness duration supports the potential impact of early diagnosis and intervention on symptom progression. However, larger sample sizes and longitudinal studies are needed to define causal relationships and clinical outcomes more robustly.