Childhood neurodivergent traits, inflammation and chronic disabling fatigue in adolescence: a longitudinal case–control study

Abstract

Objectives To test whether inflammatory processes link the expression of childhood neurodivergent traits to chronic disabling fatigue in adolescence.Design Longitudinal case–control study.Setting We analysed data from The Avon Longitudinal Study of Parents and Children (ALSPAC).Participants 8115 and 8036 children of the ALSPAC cohort at ages 7 and 9 years, respectively, 4563 of whom also completed self-report measures at age 18 years.Primary and secondary outcome measures We assessed if children scoring above screening threshold for autism/attention deficit hyperactivity disorder (ADHD) at ages 7 and 9 years had increased risk of chronic disabling fatigue at age 18 years, computing ORs and CIs for effects using binary logistic regression. Mediation analyses were conducted to test if an inflammatory marker (interleukin 6 (IL-6)) at age 9 years linked neurodivergent traits to chronic disabling fatigue at age 18 years.Results Children with neurodivergent traits at ages 7 and 9 years were two times as likely to experience chronic disabling fatigue at age 18 years (likely ADHD OR=2.18 (95% CI=1.33 to 3.56); p=0.002; likely autism OR=1.78 (95% CI=1.17 to 2.72); p=0.004). Levels of IL-6 at age 9 were associated with chronic disabling fatigue at age 18 (OR=1.54 (95% CI=1.13 to 2.11); p=0.006). Inflammation at age 9 years mediated effects of neurodivergent traits on chronic disabling fatigue (indirect effect via IL-6: ADHD b=1.08 (95% CI=1.01 to 1.15); autism b=1.06; (95% CI=1.03 to 1.10)). All effects remained significant when controlling for the presence of depressive symptoms.Conclusions Our results indicate higher risk of chronic disabling fatigue for children with neurodivergent traits, likely linked to higher levels of inflammation. The implementation of transdiagnostic screening criteria to inform support strategies to counteract risk early in life is recommended.