By: Sabiha Toni
Every two years, the Center for Disease Control (CDC) releases data about the prevalence of Spectrum Disorders. In their latest report, data demonstrates a significant change in the number of diagnoses from 2008 to 2010: a noteworthy 30% increase in prevalence in the United States. As of 2010, 1 in 68 children is reported to have been diagnosed with an ASD (Biao 2014). The large spike in numbers, however, is likely not due to drastic changes in air quality or new diets of the next generation. They are also probably not caused by radical changes in gene pools or environmental factors. Though it may be unnerving at first glance, these numbers don’t necessarily indicate a significant increase in the disorder. In fact, the hike in numbers may point towards a positive trend: progress in the levels of ASD awareness (Bloudoff-Indelicato 2014).
The CDC funded studies in 14 locations across various states to obtain statistics on ASD prevalence. The studies focused on 8 year-old children, since previous studies have shown that prevalence is highest among children at that age (Biao 2014). Using resources from educational and health records, researchers screened children in each study location for existing diagnoses or characteristics that are consistent with autistic behavior. For example, solitary behaviors or difficulties with social interaction were noted for each child. Clinicians then used the standards of the DSM-IV-TR, a diagnostic manual for mental disorders, to determine whether or not the characteristics fit the criteria for autism.
There were several significant trends observed from the data:
- The prevalence of ASD was found to be 14.7 in 1000 children, approximately 1 in 68 compared to 1 in 88 in 2008.
- Number of boys with ASDs ranged from 3.6 to 5.1 times more than girls.
- Prevalence among white children is significantly higher than among black or hispanic children.
- A greater proportion of children with ASDs were found to have average or above average IQs than in previous prevalence reports. This ratio is consistent within genders, but differences were notable between races. For example, within white children, 1 in 63 children is determined to have an ASD, while in black children, the ratio is smaller: 1 in 81. In Hispanic children, about 1 in 93 has an ASD.
- Prevalence differed by location. In Alabama, 1 in 175 is reported to have a spectrum disorder. In New Jersey, the statistic is 1 in 45.
Several of these trends have remained constant over the last decade, such as higher prevalence in males than females. Prevalence among races is also consistent, and may be attributed to socioeconomic differences and access to treatment options (Biao 2014). This also accounts for disparities between locations.
The most noticeable change was the sharp increase of ASD prevalence. However, it is part of a trend that has been steadily increasing since 2000, when the CDC first funded research on autism prevalence. Experts feel that this increase points to notable progress in regard to identifying and diagnosing ASDs as opposed to a reason for concern. It may indicate heightened awareness regarding autism among health professionals, educators, and the general public, though future studies on the subject are necessary (Bloudoff-Indelicato 2014). It is likely that the numbers will continue to increase as school systems and healthcare institutions introduce more effective screening techniques. Stigma against ASDs is also less widespread. Most people have heard of it or have an idea of autism is due to things like figures with ASD in pop culture, or even general awareness on mental health. A decline in stigma encourages people to acknowledge the disorder, and encourages families to seek help for a child with an ASD.
Baio, J. Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years – Autism Developmental Disabilities Monitoring Network, 11 Sites, United States, 2010: Center for Disease Control. 2014. 63(SS02);1-21
Bloudoff-Indelicato, M. “’Increase’ in Childhood Autism No Cause for Alarm. National Geographic. 2014. Retrieved from: http://news.nationalgeographic.com/news/2014/03/140328-autism-spectrum-disorder-rates-cdc-health-science/?rptregcta=reg_free_np&rptregcampaign=20131016_rw_membership_r1p_us_se_w#close-modal