By Michael Rock

It is no secret that there are numerous benefits to getting a diagnosis for a developmental or intellectual disability when necessary. However, there is increasing evidence that the way many such conditions are diagnosed can easily be corrupted by the individual biases of those who make such determinations.

A recent study found that the Modified Checklist for Autism in Toddlers (M-CHAT), which is the most common screening tool for it, is inaccurate. According to a recently-published study conducted at the Children’s Hospital of Philadelphia, it successfully identifies autism in fewer than 40 percent of cases. 85 percent of those it does flag turn out not to have it, but a related condition. Whitney Guthrie, the psychologist who authored the study, indicated new ways of identifying autism are necessary to successfully screen for it.

Meanwhile, researchers at the London School of Hygiene and Tropical Medicine concluded that the youngest students in a class are about one third more likely to be diagnosed with ADHD, depression, or intellectual disabilities than their older classmates. The study’s authors noted that younger children may have greater difficulty with concentration, which can cause weaker academic performance and strained relations with peers, both of which risk factors for other mental health issues.

Subjective bias along racial lines has also been acknowledged by academics at Portland State and New York Universities, who found that black students and students who are learning English as a second language at schools with relatively few other such students are more likely to get a learning disability diagnosis than those who go to schools with many other students who are black or are still learning English. Their research concluded that this phenomenon is primarily a product of racial and socioeconomic inequality, pointing to another Penn State and UC Irvine study that suggested that white students are more likely to get such a diagnosis when social influences such as poverty were controlled.

Despite these setbacks, a study commissioned by the U.S. government found that one sixth of American children had been diagnosed with a developmental disability in between 2009 and 2017, a nearly two percent increase. ADHD and autism accounted for most of the increase in diagnoses. However, some researchers do not see this as a cause for alarm. The increase may be a result of greater awareness and understanding of the conditions, as well as new diagnostic methods.

It is clear that we are currently very limited in getting a truly accurate assessment of the rates of developmental and intellectual disability. Only with more research, greater diagnostic tools, and further awareness and understanding of these conditions can we truly do the work necessary for our society to provide for the needs of all people who have them.

Michael Rock is a New York City-based reporter and self-advocate with autism. A graduate of Brandeis University, his work has appeared in Kings County Politics, Chelsea Now, Our Town, Queens County Politics, and WhoWhatWhy.