Since the adoption of the DSM-5 in 2013, autism spectrum disorder (ASD) is now a single diagnosis that recognizes and encompasses the characteristics previously associated with autism disorder, Asperger’s disorder, Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS), and Childhood Disintegrative Disorder. Rett’s Disorder that used to be part of the spectrum was dropped from the DSM all together. Additionally, the DSM-5 includes a new and related diagnosis of social communication disorder (SCD).
Causes of ASD
Currently, no singular cause for ASD has been identified. Some studies have found patterns that can explain some of the occurrences though not all (e.g., irregular levels of neurotransmitters and differences in several areas of the brain have been noted among individuals with ASD). Most researchers believe that there are likely many causes and variations of ASD, where genetics (including 10 or more genes on different chromosomes) and environment play a role. Further research is necessary in determining the relationship between genetics and ASD.
Environmental factors may include certain viruses or particular drugs (such as thalidomide and valproic acid) being taken during pregnancy. Additionally, researchers continue to investigate possible neurological, infectious, metabolic, and immunologic factors, though ASD is likely the result of many interrelated and interacting factors given the complexity and the uniqueness of each individual with ASD. ASD is not caused by bad parenting or parental practices.
How Common is ASD?
The Centers for Disease Control and Prevention (CDC, 2014) estimate that 1 in 59 children in the United States (1-2% of the population) have ASD, with ASD occurring approximately four times more commonly in males than females (Blumberg, Bramlett, & Kogan et al., 2013). ASD occurs in individuals of all races, ethnicities, social classes, and educational backgrounds.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that is characterized by impairments in social communication and interaction as well as repetitive behaviors, interests, or activities (sometimes including unusual sensory sensitivities or interests in sensory aspects of an individual’s environment).
ASD is considered to be pervasive that can present challenges that affect many areas of an individual’s life. Though individuals with ASD typically share common characteristics and challenges, ASD is considered a spectrum disorder because these characteristics affect each individual in different ways and to varying degrees of intensity.