ESSENCE: Early Neurodevelopmental Disorders

All 8 Terms & Definitions

Autism Spectrum Disorder (ASD)

A neurodevelopmental condition characterised by persistent differences in social communication and interaction, alongside restricted and repetitive behaviours, interests, or activities. The term 'spectrum' reflects enormous heterogeneity in presentation, ability, and support needs. Prevalence is approximately 1–2% of the population.

ADHD (Attention-Deficit/Hyperactivity Disorder)

Characterised by developmentally inappropriate levels of inattention, hyperactivity, and impulsivity. Three presentations are recognised in DSM-5: predominantly inattentive, predominantly hyperactive-impulsive, and combined. ADHD involves differences in executive function and dopaminergic regulation in frontostriatal circuits.

Developmental Coordination Disorder (DCD)

A motor learning disability characterised by difficulties acquiring and executing coordinated motor skills, causing significant impairment in daily activities. Often called 'dyspraxia' in the UK. Affects approximately 5–6% of school-aged children and frequently co-occurs with ADHD, DLD, and ASD.

Developmental Language Disorder (DLD)

Significant and persistent difficulties with language acquisition in the absence of hearing loss, intellectual disability, or neurological disorder. Affects around 7% of children and has a substantial genetic component. Often under-identified because early delays may be attributed to 'late talking.'

Comorbidity in ESSENCE

The co-occurrence of two or more ESSENCE conditions in the same individual. Research consistently finds that 50–80% of children with ASD also have ADHD; around 50% of those with ADHD have DCD. Understanding comorbidity is essential for comprehensive intervention planning.

Executive function deficits

A common transdiagnostic feature across ESSENCE conditions. Executive functions — working memory, inhibitory control, and cognitive flexibility — are mediated by prefrontal cortical systems. Difficulties with these functions manifest as challenges in planning, self-regulation, and adapting to change.

Neurodiversity

A perspective that frames neurological differences (as seen in autism, ADHD, dyslexia, and related conditions) as natural variation in the human brain rather than deficits or disorders. While not a clinical term, the concept shapes contemporary approaches to intervention, education, and identity.

Early intervention

The provision of therapeutic, educational, or family support services during the early childhood years (typically 0–6), when brain plasticity is greatest. Evidence supports early intervention for improving outcomes across ASD, DLD, DCD, and ADHD — and the ESSENCE framework explicitly endorses acting on early signs without waiting for a definitive diagnosis.