Anxiety in preschool children with ADHD symptoms: associations with ADHD dimensions and perinatal risk factors

Attention-deficit/hyperactivity disorder (ADHD) commonly co-occurs with anxiety, but the relative contributions of inattention (INA) and hyperactivity-impulsivity (HI) to anxiety severity in preschool children remain unclear. The role of perinatal risk factors is also insufficiently understood. This cross-sectional study included 6,188 preschool children who screened positive for ADHD symptoms based on SNAP-IV cutoffs. ADHD symptom dimensions were assessed using the Swanson, Nolan, and Pelham Rating Scale, Fourth Edition (SNAP-IV), and anxiety severity was measured with the Spence Preschool Anxiety Scale (PAS). Perinatal depression, fetal growth restriction (FGR), hypertensive disorders of pregnancy (HDP), and gestational diabetes mellitus were obtained from parent-reported questionnaires. Multivariable regression, restricted cubic spline, subgroup, and interaction analyses were performed after adjustment for sociodemographic and perinatal covariates. Both INA and HI were independently associated with anxiety severity, with a stronger association for INA. INA showed a nonlinear association with anxiety, with a steeper increase at low-to-moderate levels followed by a plateau at higher levels. Children with inattentive and combined symptom presentations had higher anxiety scores than those with the hyperactive-impulsive presentation. Perinatal depression and FGR were independently associated with greater anxiety severity. A significant interaction suggested a stronger association between INA and anxiety severity among children exposed to HDP. INA may be more strongly associated with anxiety severity than HI in preschool children with ADHD symptoms. ADHD symptom dimensions and perinatal context should be jointly considered in the early identification of anxiety risk.