Neurodevelopmental disorder

Neurodevelopmental disorders (NDDs) are a diverse group of complex behavioral and cognitive conditions caused by the abnormal, or disrupted development of the brain, or by injury or infection during early childhood. These conditions generally appear in early childhood, usually pre-school age, and can persist into adulthood. NDDs are different from neurocognitive disorders that are acquired and not developmental. Neurodevelopmental disorders are categorized in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) into six groups: intellectual disabilities, communication disorders, autism spectrum disorder, attention deficit hyperactivity disorder, motor disorders, and specific learning disorders. The international classification of diseases ICD-11 published by the World Health Organisation (WHO), includes NDDs in the general heading of Mental, behavioral or neurodevelopmental disorders, and lists them in seven groupings. A factsheet on Mental disorders (2025) published by WHO states that there are many types of mental disorder and lists NDDs as one. It describes a mental disorder, also called a mental health condition as a noted impairment in cognition, emotional or behavioral regulation. More than one NDD may be present, giving overlapping symptoms, and are often complicated by the co-occurrence of other conditions. For instance a tic disorder, a type of motor disorder, may also be comorbid with a movement disorder, another mental disorder, or a substance use disorder. Some NDDs such as Down syndrome have a genetic cause. Other possible causes include environmental factors such as prenatal stress, early developmental stress, and fetal exposure to toxicants; pollution, infections, and traumatic brain injury. NDDs are diverse with treatments targeted at the disorder that may include medications and other interventional therapies.