Childhood Infections Could Increase Mental Illness Risk

Children who are hospitalized for infections and/or treated with anti-infective drugs have an increased risk for mental disorders, according to the results of a recent study.

Although infections have been shown to be associated with increased risk of schizophrenia and depression, the association between all treated infections and a variety of mental disorders is less well understood.

The researchers conducted a population-based cohort study involving 1,098,930 participants from Danish nationwide registers. Severe infections required hospitalization and less severe infections treated with anti-infective agents were identified, as were mental disorders diagnosed in a hospital setting and redeemed prescription for psychotropic medications.

Overall, hospitalization-requiring infections were associated with an increased risk of mental disorder diagnosis (hazard risk ratio [HRR] 1.84) and with increased risk of psychotropic medication prescription (HRR 1.42). Infections treated with anti-infective agents were also associated with increased risk of mental disorder diagnosis (HRR 1.40) and prescription (HRR 1.22), with antibiotics being associated with particularly increased risk.

The risk of mental disorders increased in a dose-response association following infection, as well as with the temporal proximity of the last infection. The disorders most affected included schizophrenia spectrum disorders, obsessive-compulsive disorder, personality and behavior disorders, autistic spectrum disorder, attention-deficit/hyperactivity disorder, oppositional defiant disorder and conduct disorder, and tic disorders.

“These findings might be explained by direct influences of infections, genetics, or disturbances of the microbiome; however, due to the study design, other confounding factors need to be considered when interpreting our results. A better understanding of the role of infections and antimicrobial therapy in the pathogenesis of mental disorders might lead to new methods for the prevention and treatment of these devastating disorders.”

—Michael Potts

Reference: 

A nationwide study in Denmark of the association between treated infections and the subsequent risk of treated mental disorders in children and adolescents [published online December 5, 2018]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2018.3428.