Adverse childhood experiences and comorbidity in a cohort of people who have injected drugs.

Background: Childhood adversity is associated with the onset of harmful adult substance use and related health problems, but most research on adversity has been conducted in general population samples. This study describes the prevalence of adverse childhood experiences in a cohort of people who have injected drugs and examines the association of these adverse experiences with medical comorbidities in adulthood.

Methods: Six hundred fifty three adults were recruited from a 30-year cohort study on the health of people who have injected drugs living in and around Baltimore, Maryland (Median age = 47.5, Interquartile Range = 42.3-52.3 years; 67.3% male, 81.1% Black). Adverse childhood experiences were assessed retrospectively in 2018 via self-report interview. Lifetime medical comorbidities were ascertained via self-report of a provider diagnosis. Multinomial logistic regression with generalized estimating equations was used to examine the association between adversity and comorbid conditions, controlling for potential confounders.

Results: Two hundred twelve participants (32.9%) reported 0-1 adverse childhood experiences, 215 (33.3%) reported 2-4, 145 (22.5%) reported 5-9, and 72 (11.1%) reported ≥10. Neighborhood violence was the most commonly reported adversity (48.5%). Individuals with ≥10 adverse childhood experiences had higher odds for reporting ≥3 comorbidities (Adjusted Odds Ratio = 2.9, 95% CI = 1.2 - 6.8, p = .01).

Conclusions: Among people who have injected drugs, adverse childhood experiences were common and associated with increased occurrence of self-reported medical comorbidities. Findings highlight the persistent importance of adversity for physical health even in a population where all members have used drugs and there is a high burden of comorbidity.