Abstract
OBJECTIVE: Childhood adversities are linked to eating disorders (EDs), but their cumulative and evolving nature is often overlooked. This study employs a comprehensive measure of adversities, captured through trajectories across ages 0-9, to examine associations with (1) clinically diagnosed EDs at ages 10-18 and (2) a composite outcome of diagnosed and self-reported ED symptoms at age 18. Differences between diagnosed and non-diagnosed EDs were also assessed. METHODS: Data from children born in Denmark between 1996 and 2003 (total population; N = 500,240) and participants in the 18-year follow-up of the Danish National Birth Cohort (DNBC-18; N = 43,687, 50% of those eligible for invitation) were used. Diagnosed EDs were identified through national registers, and non-diagnosed EDs through the DNBC-18. Adversities were grouped into three predefined dimensions: material deprivation, loss or threat of loss, and family dynamics. A group-based multi-trajectory model identified trajectories from ages 0-9. Associations were analyzed using quasi-Poisson and multinomial logistic regression. RESULTS: Four trajectory groups were identified: low adversity (72.1%), material deprivation (18.0%), loss or threat of loss (5.5%), and high adversity (4.4%). < 1% had a diagnosed ED, while 2.5% had a non-diagnosed ED, both more common in females. While no overall associations were found in the total population, the high adversity group had a higher risk of eating disorders not otherwise specified (EDNOS) compared to the low adversity group (IRR = 1.58, 95% CI: 1.16-2.12). In the DNBC-18 analyses, a higher risk in the high adversity group compared to the low adversity group, was entirely driven by non-diagnosed EDs (RRR = 1.73, 95% CI: 1.37-2.20). CONCLUSION: Individuals exposed to high adversity had a higher risk of EDs, particularly non-diagnosed cases, highlighting a diagnostic gap shaped by differences in symptom recognition, help-seeking, and access to care.