Family socioeconomic status and attention-deficit/hyperactivity disorder symptoms in preschool children: a cross-sectional study of 21,366 parent–child dyads in Yan’an, western China

Abstract

Socioeconomic status (SES) is a well-established determinant of child mental health, yet evidence from large preschool populations in western China remains scarce. This study examined the association between family SES and attention-deficit/hyperactivity disorder (ADHD) symptoms in preschool children. We conducted a cross-sectional survey among 21,366 parent–child dyads recruited from 189 public kindergartens in a western Chinese city using stratified cluster sampling. A composite family SES index was derived from parental occupation, education, and household income through principal component analysis. Child ADHD symptoms were measured using the Strengths and Difficulties Questionnaire (SDQ) hyperactivity/inattention subscale. Survey-weighted linear and logistic regression models adjusted for child age, sex, preterm birth, parental smoking and alcohol use, respondent role, and respondent age, with cluster-robust standard errors accounting for kindergarten-level clustering. Higher family SES was significantly associated with lower ADHD symptom scores. In the fully adjusted linear model, each 1-SD increase in SES corresponded to a 0.17-point decrease in the SDQ hyperactivity/inattention score (95% CI: –0.18 to –0.15, P < 0.001). Logistic regression showed a 27% reduction in the odds of elevated ADHD symptoms per 1-SD increase in SES (OR = 0.73, 95% CI: 0.64 to 0.84, P < 0.001). A clear dose–response relationship emerged across SES tertiles (P for trend < 0.001). Stratified analyses demonstrated consistent associations across all subgroups, with no significant effect modification after Bonferroni correction. Multiple imputation and restricted cubic spline analyses confirmed the robustness of these findings. Higher family SES is associated with lower ADHD symptom levels in preschool children from western China, with a clear dose-response relationship. These findings underscore the importance of socioeconomic resources in early childhood mental health and may inform the development of targeted intervention strategies for low-SES families. Longitudinal studies are warranted to establish causality and elucidate underlying mechanisms.