A 'double disadvantage': neurodevelopmental profile and poverty confer synergistic risk of youth justice involvement.

Background: It is known that children with lower neurodevelopmental abilities and children who live in poverty are at increased risk of contact with the criminal justice system, but whether these two risk factors interact is unknown.

Methods: We used linked data from 519,920 children born in 2001/2002, who attended school in England. Prospective analysis tested whether Early Years Foundation Stage Profile (EYFSP) indexing functional development across six domains and pupil characteristics indexing poverty at age 4/5, predicted a caution or conviction by age 15/16.

Findings: Higher scores on the EYFSP (indicating better functional development) were associated with decreased odds of a caution or conviction by the age of 15/16. Being eligible for Free School Meals (living in absolute poverty) at age 4/5 was associated with increased odds of having a caution or conviction by age 15/16. There was a statistical interaction indicating synergistic risk conferred by these two risk factors.

Interpretation: Poverty and lower functional development independently confer risk of criminalisation, and together confer a 'double disadvantage'. Structural public health interventions should reduce the criminalisation of children by boosting functional development through Special Educational Needs support in schools, and by reducing the number of children living in absolute poverty.