Two Studies by Kenneth Gadow, PhD and Colleagues Examine Relationships Between Impairment and Psychiatric Symptoms in Young People

Kenneth Gadow, PhD

Two recent articles by Professor Kenneth Gadow, PhD and colleagues provide new information about relationships between impairment caused by psychiatric disorders and the number and severity of symptoms of these disorders in children and adolescents.

Because the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM) typically requires a certain number of symptoms and a certain degree of impairment in order to establish a diagnosis, the relationship between the two has important consequences for both clinical care and research.

In one study, the researchers analyzed ratings of impairment and symptoms by parents and teachers of 636 young people between 6 and 18 years old who were referred for psychiatric evaluation. They discovered that while the severity of impairment was moderately to highly correlated with both the number and severity of symptoms in both parent and teacher ratings, the relationships between impairment and symptoms were highly complex and variable across disease types and type of informant. They found, for example, that while many young people who met impairment criteria for several diseases did not meet symptom cutoff criteria, most children who met symptom criteria met impairment criteria.

In a second study they addressed a similar set of questions using data from a different population of children aged 6 to 12 who were diagnosed with autism spectrum disorder. In this population, questions about the relationships between impairment and symptoms are complicated by uncertainties about the relationship between autism and co-occurring psychiatric symptoms. While it is relatively clear in children without autism that impairment is the result of psychiatric disease, it is not clear in children with autism whether impairment results from the core features of autism or from co-occurring psychiatric disorders or some combination of the two.

In the second study they found that the majority of children were rated by parents (81%) or teachers (86%) as being impaired by one or more psychiatric disorders. These rates were similar to those found in the sample of clinic-referred children not diagnosed with autism spectrum disorder (75% and 79%). And although a larger percentage of students met impairment cutoff scores than symptom cutoff scores, the correlation between the two was sufficient to allow symptom scores to stand as a reasonable estimate of impairment in children with autism spectrum disorder.

Aaron Kaat, MA and Luc Lecavalier, both from the Ohio State University, co-authored the papers with Dr. Gadow. The first article, titled “Relations of symptom-induced impairment with other illness parameters in clinic-referred youth,” was published by the Journal of Child Psychology and Psychiatry on April 16, 2013. The other, titled “Psychiatric Symptom Impairment in Children with Autism Spectrum Disorders, was published in the Journal of Abnormal Child Psychology on April 20, 2013.

Posted: May 23, 2013