Neurodevelopmental disorders is an umbrella term that incorporates a range of conditions characterised by some form of disruption to ‘typical’ brain development. These disorders share aetiological pathways that have genetic, social and environmental risk factors. Neurodevelopmental disorders often have core features in common and they frequently co-occur. Long-term impairment is characteristic, although key features may vary over the life span. This chapter covers key aspects of the aetiology of neurodevelopmental disorders, in particular focusing on those found in forensic settings (such as autism spectrum disorder, intellectual disability, attention deficit and hyperactivity disorder and fetal alcohol spectrum disorder). The impact of genetic, social and environmental risk factors is considered. The chapter considers the aetiology of neurodevelopmental disorders as relevant to forensic settings.

The chapter provides an introduction to neurodevelopmental disorders and summarises recent advances in published research, focusing on the very early development and function of the human brain. The main influences on the current delivery and development of forensic healthcare services is set within the context of available policy and guidance, which is limited in part by the available research evidence to inform it. The book is divided into three sections. The first provides an overview with an introduction to individual disorders and covers aetiology, prevalence, comorbid mental disorder and relevant policy to date. The second section focuses on the clinical aspects of the range of disorders including screening, assessment, diagnosis, risk assessments and therapeutic approaches. The final section examines the pathways through the criminal justice system from police to court to disposal and addresses the specific aspect of fitness to plead or stand trial for those with neurodevelopmental disorders. This section also describes current relevant legislation within the UK as well as forensic services for those with such disorders from a national and international perspective.

Attention-deficit/hyperactivity disorder (ADHD) is associated with a range of adverse outcomes. One of many potential adverse trajectories for those with ADHD is involvement in criminal offending. Meta-analyses have reported increased prevalence rates of ADHD in youth and adult offender populations. The prevalence of comorbid disorders in offender populations is common, but this appears to be increased in those with ADHD, which in turn complicates diagnosis and treatment. This chapter outlines the prevalence of ADHD in offender populations and considers gender and cultural effects. The relationship between ADHD and criminal offending is discussed, including the onset and type of offending, recidivism, progress within institutional establishments, comorbidity and long-term consequences. theoretical frameworks for understanding the association between ADHD and criminal offending are also considered. The chapter also highlights the economic consequences of ADHD within offender populations and more broadly within society. We consider system barriers and practical strategies that may be implemented to identify and meet the needs of offenders with ADHD.