No associations between neuroborreliosis in children and psychiatric neurodevelopmental disorders: a nationwide, population-based, matched cohort study

BACKGROUND: It has been suggested that neuroborreliosis in children can manifest as psychiatric neurodevelopmental disorders or cause long-term neurodevelopmental sequelae. However, previous studies were limited by size and design.

METHODS: We performed a nationwide, population-based, matched cohort study in Denmark between 1995 and 2021. We included all Danish residents <16 years old with a positive Borrelia burgdorferi sensu lato intrathecal antibody index test (children with neuroborreliosis). To form a comparison cohort, we randomly extracted individuals from the general population matched on date of birth and sex 10:1 to children with neuroborreliosis. We calculated hazard ratios (HRs) with 95% CIs of contact to departments of psychiatry, diagnosis of attention deficit disorder, diagnosis of learning or intellectual developmental disorders, or receipt of psychostimulants for attention deficit disorder among children with neuroborreliosis compared with comparison cohort members. We did a sensitivity analysis in the form of a case-control study, where we examined whether these outcomes were more frequent among children with neuroborreliosis than in the comparison cohort before study inclusion to account for differential delay in diagnosis.

RESULTS: We included 1,132 children with neuroborreliosis and 11,320 comparison cohort members with an observation time of 168,858 person-years. We found no associations between neuroborreliosis and contact with departments of psychiatry (HR: 1.0, 95% CI 0.9-1.2), diagnosis of attention deficit disorder (HR: 0.9, 95% CI 0.6-1.3), diagnosis of learning or intellectual developmental disorders (HR 0.8, 95% CI 0.5-1.4), or receipt of psychostimulants for attention deficit disorder (HR: 0.8, 95% CI 0.6-1.1). Also, in the sensitivity analyses, these outcomes were not more present among children with neuroborreliosis than in the comparison cohort before study inclusion.

CONCLUSIONS: Our results do not support that neuroborreliosis in children manifests as psychiatric neurodevelopmental disorders or causes long-term neurodevelopmental sequelae.