Are Infections Associated With Increased Risk of Later Mental Disorders During Childhood, Adolescence?

A new study published in JAMA used Danish nationwide registries to investigate an association between infections treated since birth and subsequent risk of treated childhood and adolescent mental disorders. Among nearly 1.1 million people born in Denmark between 1995 and 2012, about 42,000 (3.9 percent) were hospitalized for any mental disorder and nearly 57,000 (5.2 percent) redeemed a prescription for psychotropic medication. Infections requiring hospitalization were associated with subsequent increased risk of hospitalization for any mental disorder and increased risk of psychotropic medication use. 

Infections treated with medication, especially antibiotics, were associated with increased risk. Risks differed among mental disorders. Schizophrenia spectrum disorders, obsessive-compulsive disorder, personality and behavior disorders, mental retardation, autism spectrum disorder, attention-deficit/hyperactivity disorder, oppositional defiant disorder and conduct disorder, and tic disorders were associated with the highest risks after infections. This is an observational study and other factors might explain the results including the consequences of infections on the developing brain and other influences such as genetics and disturbances of the gut biome.