Autism [Autism Spectrum Disorder] Part 1 [Diagnosis, Prevalence and Comorbidity]
Autism spectrum disorders (ASD) are a diverse group of conditions. They are characterized by some degree of difficulty with social interaction and communication. Other characteristics are atypical patterns of activities and behaviours, such as difficulty with transition from one activity to another, a focus on details and unusual reactions to sensations.
The abilities and needs of autistic people vary and can evolve over time. While some people with autism can live independently, others have severe disabilities and require life-long care and support. Autism often has an impact on education and employment opportunities. In addition, the demands on families providing care and support can be significant. Societal attitudes and the level of support provided by local and national authorities are important factors determining the quality of life of people with autism.
Characteristics of autism may be detected in early childhood, but autism is often not diagnosed until much later.
People with autism often have co-occurring conditions, including epilepsy, depression, anxiety and attention deficit hyperactivity disorder as well as challenging behaviours such as difficulty sleeping and self-injury. The level of intellectual functioning among autistic people varies widely, extending from profound impairment to superior levels.
Epidemiology
It is estimated that worldwide about 1 in 100 children has autism. This estimate represents an average figure, and reported prevalence varies substantially across studies. Some well-controlled studies have, however, reported figures that are substantially higher. The prevalence of autism in many low- and middle-income countries is unknown.
Autism - also referred to as autism spectrum disorder ̶ constitutes a diverse group of conditions related to development of the brain.
About 1 in 100 children has autism.
Characteristics may be detected in early childhood, but autism is often not diagnosed until much later.
The abilities and needs of autistic people vary and can evolve over time. While some people with autism can live independently, others have severe disabilities and require life-long care and support.
Evidence-based psychosocial interventions can improve communication and social skills, with a positive impact on the well-being and quality of life of both autistic people and their caregivers.
Care for people with autism needs to be accompanied by actions at community and societal levels for greater accessibility, inclusivity and support.
Medical comorbidities are more common in children with autism spectrum disorders (ASD) than in the general population. Some genetic disorders are more common in children with ASD such as Fragile X syndrome, Down syndrome, Duchenne muscular dystrophy, neurofibromatosis type I, and tuberous sclerosis complex. Children with autism are also more prone to a variety of neurological disorders, including epilepsy, macrocephaly, hydrocephalus, cerebral palsy, migraine/headaches, and congenital abnormalities of the nervous system. Besides, sleep disorders are a significant problem in individuals with autism, occurring in about 80% of them. Gastrointestinal (GI) disorders are significantly more common in children with ASD; they occur in 46% to 84% of them. The most common GI problems observed in children with ASD are chronic constipation, chronic diarrhoea, gastroesophageal reflux and/or disease, nausea and/or vomiting, flatulence, chronic bloating, abdominal discomfort, ulcers, colitis, inflammatory bowel disease, food intolerance, and/or failure to thrive. Several categories of inborn-errors of metabolism have been observed in some patients with autism including mitochondrial disorders, disorders of creatine metabolism, selected amino acid disorders, disorders of folate or B12 metabolism, and selected lysosomal storage disorders. A significant proportion of children with ASD have evidence of persistent neuroinflammation, altered inflammatory responses, and immune abnormalities. Anti-brain antibodies may play an important pathoplastic mechanism in autism. Allergic disorders are significantly more common in individuals with ASD from all age groups. They influence the development and severity of symptoms.