Abstract
We examined the trajectories of 1520 UK pre‐school children’s mental health symptoms (conduct problems, emotional problems, and hyperactivity/inattention) in an intensive longitudinal study in the first year of the COVID‐19 pandemic. We found that symptom severity improved following the end of the first national lockdown, and worsened around the later national lockdowns. Crucially, symptom trajectories were moderated by attending childcare (with greater decline in severity for all symptom categories over time for children attending childcare compared to those who did not) and overall symptom severity was moderated by parent mental ill health (symptoms were less severe in all symptom categories for children whose parents did not have a mental health problem than for children whose parents did report a mental health problem).