Use of Antibiotics and Risk of Psychiatric Disorders in Newly Diagnosed Cancer Patients: A Population-Based Cohort Study in Sweden

Kejia Hu*, Karin E. Smedby, Arvid Sjolander, Scott Montgomery, Unnur Valdimarsdottir, Lars Engstrand, Fang Fang, Katja Fall

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Background: Antibiotic-induced dysbiosis is associated with an increased risk of depression and anxiety in the general population.A diagnosis of cancer is associated with an immediately and dramatically elevated risk of psychiatric disorders, but the potential influence of prediagnostic antibiotic-induced dysbiosis is unknown. Methods: Based on a national cohort of cancer patients in Sweden, we included 309,419 patients who were diagnosed with a first primary malignancy between July 2006 andDecember 2013. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of first-onset psychosis, depression, anxiety, or stress-related disorders during the first year after cancer diagnosis for antibiotic use during the year before cancer diagnosis. Results: Compared with no antibiotic use, use of antibiotics was associated with a higher rate of the aforementioned psychiatric disorders (HR, 1.23; 95% CI, 1.16-1.30) after adjustment for sociodemographic factors, comorbidity, potential indications for antibiotics, and cancer stage and type. The magnitude of the association was higher for broad-spectrum antibiotics (HR, 1.27; 95% CI, 1.18-1.37), higher doses (HR, 1.32; 95% CI, 1.22-1.44), more frequent use (HR, 1.33; 95% CI, 1.21-1.46), and recent use (HR, 1.26; 95% CI, 1.17- 1.35). Conclusions: Use of antibiotics, especially of broad-spectrum type, of high dose and frequency, with recent use, was associated with an aggravated risk of psychiatric disorders, compared with no antibiotic use.

Original languageEnglish
Pages (from-to)528-535
Number of pages8
JournalCancer Epidemiology Biomarkers and Prevention
Issue number3
Publication statusPublished - 1 Mar 2022

Bibliographical note

Funding Information:
This study was supported by grants awarded to K. Hu by China Scholarship Council (No. 201806240005), to F. Fang by Swedish Cancer Society (20 0846 PjF), the Swedish Research Council for Health, Working Life and Welfare (No. 2017-00531), and Karolinska Institutet (Senior Researcher Award, Strategic Research Area in Epidemiology Award), to K. Fang by Orebro€ University (Orebro€ University Strategic Funds). The researchers were independent of the funding agencies. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Funding Information:
F. Fang reports grants from Swedish Cancer Society outside the submitted work. No disclosures were reported by the other authors.

Publisher Copyright:
© 2022 American Association for Cancer Research Inc.. All rights reserved.

Other keywords

  • Anti-Bacterial Agents/adverse effects
  • Cohort Studies
  • Dysbiosis
  • Humans
  • Mental Disorders/epidemiology
  • Neoplasms/drug therapy
  • Proportional Hazards Models
  • Registries
  • Risk Factors
  • Sweden/epidemiology


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