TOPLINE

Hospitalization due to an acute infection, especially infectious encephalitides, was associated with an elevated risk of developing psychiatric and neurologic disorders within the subsequent 2 years, a large US study showed.

METHODOLOGY

• A retrospective multicohort study included patients hospitalized between 2014 and 2018 in the US with a 2-year follow-up period; data were analyzed from the TriNetX US Collaborative Network.
• More than 1 million matched pairs of individuals (mean age, 48.4 years; 51.5% women; 65.3% White individuals) were included. Individuals hospitalized for noninfectious causes and the general population were compared to those hospitalized with an infection in any of 10 body systems: infectious encephalitides, infectious hepatitides, meningitides, sexually transmitted infections, and infections of the bones, heart, gastrointestinal tract, respiratory tract, skin, and urinary tract.
• Cohorts were stratified into four age groups: children (≤ 18 years), young adults (19-44 years), middle-aged adults (45-64 years), and older adults (≥ 65 years).
• The primary outcome was risk for14 neurologic or psychiatric disorders diagnosed between 1 month and 2 years after hospital admission, including a composite category of cognitive deficits; anxiety, mood, and psychotic disorders; insomnia; epilepsy/seizures; encephalitis; and ischemic stroke.
• Measures included the restricted mean time lost (RMTL) ratio and the absolute risk difference at 2 years. Propensity score matching was used to adjust for potential confounders, including sociodemographic factors, comorbidities across body systems, history of vaccinations, and prior or concurrent use of antidepressants or antipsychotics.

TAKEAWAY

• Compared with individuals hospitalized for noninfectious causes, those hospitalized with infections had an increased risk of developing neurologic and psychiatric disorders, with elevated risks observed in 116 of 140 infection-disorder tests.
• Encephalitis was the disorder with the highest relative risk (median RMTL ratio after cardiac infection, 6.54; P = 2.0 × 10^-11). Cognitive deficits were associated with the greatest increase in absolute risk (median, 8.76%), and this increase was most pronounced after cardiac infections (risk difference, 12.37%).
• Infectious encephalitides were identified as the leading risk factor for seven psychiatric and neurologic disorders and ranked among the top three risk factors for 12 disorders. Similar trends were observed when individuals hospitalized with infections were compared with the general population.
• Absolute risk differences for individuals hospitalized with infections compared to those for other causes were, on average, 0.33% lower in children (P < .001) and 0.42% higher in older adults (P < .001) than the overall average.

IN PRACTICE

“These findings suggest that infections are important risk factors for psychiatric and neurologic disorders, can guide research into underlying mechanisms, and may help improve future pandemic preparedness,” the investigators wrote.

SOURCE

This study was led by Maxime Taquet, PhD, Department of Psychiatry, University of Oxford, Oxford, England. It was published online on July 15 in JAMA Psychiatry.

LIMITATIONS

This study was limited by reliance on electronic health record data, inclusion of hospitalized patients alone that may not generalize to milder infections, possible residual confounding and reverse causation, a lack of assessment of mediation by acute complications or treatment effects, lack of data on reasons for hospitalization, analysis by body system rather than pathogen, and possible overlap of individuals across multiple cohorts.

DISCLOSURES

This study was funded by the National Institute for Health Research Oxford Health Biomedical Research Centre and the Sir Jules Thorn Charitable Trust. Disclosure information for the study investigators is available in the original study publication.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.