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.
Classification Neurodevelopment disorders (NDDs) are diverse and complex behavioral and cognitive conditions. Neurodevelopment itself is a wide-ranging process prone to abnormalities that may be responsible for the early presentation of the intellectual and functional impairments of the NDDs. Symptoms of an NDD may often overlap with another condition (including another NDD) making diagnosis and appropriate treatment a challenge. The six groups of disorders categorised by DSM5 are intellectual disability, communication disorder, autism, attention deficit hyperactivity disorder, motor disorders, and specific learning disorders.
Intellectual disability Intellectual disability, also disorder of intellectual development, and known as learning difficulty (in the United Kingdom and different from learning disability), formerly mental retardation, is a neurodevelopmental disorder characterized by significant impairment in intellectual and adaptive functioning. The level of impairment may be mild, moderate, severe or profound. Causes may be either developmental or genetic. Children with intellectual disability typically have an intelligence quotient (IQ) below 70 and deficits in at least two adaptive behaviors that affect everyday living.
Communication disorders A communication disorder is any disorder that affects an individual's ability to comprehend, detect, or apply language and speech to engage in dialogue effectively with others. This also encompasses deficiencies in verbal and non-verbal communication styles. The delays and disorders can range from simple sound substitution to the inability to understand or use one's native language.
Autism spectrum disorder Autism, also known as autism spectrum disorder (ASD), is a condition characterized by impairment in social communication and interaction, as well as a need or strong preference for predictability and routine, sensory processing differences, focused interests, or repetitive behaviors. Features of autism are present from early childhood and the condition typically persists throughout life. Autism is classified as a neurodevelopmental disorder, and a diagnosis requires professional assessment that these characteristics cause significant challenges in daily life beyond what is expected given a person's age and social environment. Because autism is a spectrum disorder, presentations vary and support needs range from minimal assistance to full-time, 24-hour care.
Attention deficit hyperactivity disorder
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by executive dysfunction occasioning symptoms of inattention, hyperactivity, impulsivity and emotional dysregulation that are excessive and pervasive, impairing in multiple contexts, and developmentally-inappropriate. ADHD symptoms arise from executive dysfunction, and emotional dysregulation is often considered a core symptom. Difficulties in self-regulation such as time management, inhibition and sustained attention may cause poor professional performance, relationship difficulties and numerous health risks, collectively predisposing to a diminished quality of life and a direct average reduction in life expectancy of 13 years. ADHD is associated with other neurodevelopmental and mental disorders as well as non-psychiatric disorders, which can cause additional impairment.
Motor disorders Motor disorders are neurodevelopmental disorders that cause abnormal and involuntary movements. They can result from damage to the motor system. They were redefined in DSM-5. Motor disorders include developmental coordination disorder, stereotypic movement disorder, and tic disorders including Tourette's. Motor disorders are distinct from movement disorders.
Developmental coordination disorder Developmental coordination disorder is an impaired coordination that results from impaired motor planning.
Stereotypic movement disorder Stereotypic movement disorder displays restrictive or repetitive movements such as hand waving or head banging that are prolonged and intense causing significant impairment.
Specific learning disorders
Deficits in any area of information processing can manifest in a variety of specific learning disabilities (SLD). It is possible for an individual to have more than one of these difficulties. This is referred to as comorbidity or co-occurrence of learning disabilities.
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