Antibiotic exposure and childhood attention-deficit/hyperactivity disorder: systematic review and meta-analysis

Psychopharmacology (Berl). 2021 Nov;238(11):3055-3062. doi: 10.1007/s00213-021-05989-3. Epub 2021 Oct 23.


Background: Disturbances of gastrointestinal microbiome may result in the development of attention-deficit/hyperactivity disorder (ADHD). Antibiotic therapy is commonly known to influence the gastrointestinal microbiome. However, results from studies on the association between antibiotic exposure and ADHD have been inconsistent.

Methods: Several databases (PubMed, PsychInfo, EMBASE) were searched on January 1, 2021, to identify relevant studies. A random effects model was used to calculate the pooled risk estimate. Statistical heterogeneity was tested using the chi-square test and the I2 statistic.

Results: There were four risk estimates on antibiotic intake during pregnancy and eight risk estimates on antibiotic intake after birth. The pooled odds ratio for ADHD comparing antibiotic exposure with non-exposure during pregnancy was 1.14 (95% confidence interval [CI], 1.10-1.18). The pooled odds ratio with postnatal antibiotic exposure was 1.12 (95% CI, 0.99-1.26). Substantial heterogeneity existed among these analyses. The timing of antibiotic exposure, type of antibiotic, and number of antibiotic intakes might influence the association between antibiotic exposure and ADHD.

Conclusions: Our findings suggest that maternal antibiotic intake during pregnancy may be associated with an increased risk of ADHD in the offspring. However, there was insufficient evidence for the association between antibiotic intake after birth and ADHD risk. Further studies should be performed before a definitive conclusion can be established.

Keywords: Antibiotic; Attention-deficit/hyperactivity disorder; Microbiome.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Anti-Bacterial Agents / adverse effects
  • Attention Deficit Disorder with Hyperactivity* / drug therapy
  • Attention Deficit Disorder with Hyperactivity* / epidemiology
  • Child
  • Female
  • Gastrointestinal Microbiome*
  • Humans
  • Odds Ratio
  • Pregnancy
  • Prenatal Exposure Delayed Effects* / chemically induced
  • Prenatal Exposure Delayed Effects* / epidemiology


  • Anti-Bacterial Agents

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