Exploring the relationship between relative school starting age, emotional development and ADHD diagnosis in England.

Issues and Initial research question:
Research literature indicates that the relatively youngest in a cohort are significantly more likely to exhibit behaviours and symptoms associated with, be diagnosed with and receive medication for ADHD. Indeed, they have been found to present as less persistent in behaviour, more irritable, inattentive, hyperactive and less adaptive to change. Furthermore, August-born children in England are more likely to be diagnosed with a special education need, with those in receipt of free school meals disproportionately impacted. Literature has indicated that exposure to informal schooling at too young an age could be contributing to the environmental factors causing ADHD, and that teacher perceptions and recognition of ADHD symptoms could be heavily influenced by differences in school starting age.
Therefore, this project proposes a novel and comprehensive analysis of English data to provide greater understanding into the unique English context so to uncover the inequalities in emotional development and ADHD diagnosis. The analysis will include consideration of mother's highest level of education as a moderating factor. Neither this context for analysis nor this variable has previously been addressed within research literature.
Research Questions:
1. How does relative school starting age affect behaviours typically associated with emotional development, when controlling for gender, socio-economic background and mother's highest level of education? And does the affect persist into mid-to-late adolescence?
2. How does the prevalence of ADHD diagnosis among August-born and September born children compare across differences in gender, socio-economic background, mother's highest level of education and birth cohort?
Intended methodology and research design:
A longitudinal analysis using quantitative methods will utilise two ESRC longitudinal datasets to track the persistence of relative school starting age effects on behaviours associated with emotional development into mid-to-late adolescence.
The focal study will be the Millennium Cohort Study (MCS) as it includes data on mental health at multiple waves from 9 months through age 17 for a cohort born in 2001. Significantly, the timing of this study is ideal for the context of this project, coinciding with the so called 'schoolification' of Early Years Education. The Next Steps Study only collected data on children from age 14 onwards but enables comparison of effects of school starting age on adolescents for a cohort born in the early 1990s, before the 'schoolification' of early education. Both studies have been linked to data from the National Pupil Database, enabling
incorporation of information on Key Stage achievement outcomes, SEN diagnoses and school absences.
In addition, a focus of the project is the way relative age manifests in the first year of schooling as a potential shaper of future interactions and behaviour. For this purpose, analysis of data from the Early Years Foundation Stage (EYFS) profile, collected from the Reception teachers of the MCS cohort, will be analysed in relation to month of birth. Then, Quantitative methods for modelling complex individual trajectories over time, such as latent growth curve modelling, will be used to test whether the August-born children assessed with social and emotional developmental issues at age 5 in the EYFS profile, follow the same
academic and emotional trajectories as their September-born equivalents. This test will allow us to gain understanding into whether the timing of a child's birth within the school year, the age they enter and complete formal schooling and thus their perceived immaturity, effects long-term emotional outcomes and academic careers. However, estimating trajectories can be complicated because of the measurement error involved in the initial scores can lead to biases.