Grants will help clarify, coordinate research on mental health

The National Institute of Mental Health has awarded two grants, totaling more than $4 million, to the University and the National Opinion Research Center to obtain data that can resolve differences among several competing systems of diagnostic classification used to describe children’s mental-health problems.

The lack of common terminology has been a major stumbling block for research in the field of children’s mental health, hampering cooperation between research teams and comparisons of related studies.

“Researchers who study children’s mental-health problems currently labor in a veritable Tower of Babel,” explained Benjamin Lahey, Professor in Psychiatry and principal investigator on both grants. “Different researchers speak widely varied professional languages as they try to define mental-health diagnoses and measure symptoms.”

Because these varying diagnostic languages rely on different “words” (symptoms and other diagnostic criteria) and “syntax” (rules for putting together the symptoms to define syndromes), the results of studies using one diagnostic language often cannot be combined with findings from studies using another diagnostic language, explained Lahey.

The dominant diagnostic language for child and adolescent psychiatrists in the United States is that of the American Psychiatric Association’s Diagnostic and Statistical Manual. However, the symptoms and diagnostic criteria for children’s mental disorders in this manual have been revised many times in recent years, “often without adequate empirical justification and resulting in considerable confusion,” noted Lahey.

Adding to the mix, mental-health researchers outside the United States often use The International Classification of Diseases. Although the symptoms of mental disorders of children and adolescents used in these two diagnostic manuals were brought into agreement in the most recent editions of them, the syndromes of child and adolescent mental disorder are defined in very different ways.

Complicating matters further, many mental-health researchers shun both manuals and use instead various mental-health rating scales. These scales assess mental-health problems using sets of symptoms that only partially overlap with the standard manuals, and they define the syndromes of mental disorder in ways often quite different from the two diagnostic manuals.

The two NIMH-supported studies will collect data to resolve these differences. “We expect that a new diagnostic nomenclature for children’s mental health will emerge that combines the most valid symptoms and diagnostic rules from each of several current systems,” said Lahey.

Both studies will use a new interview instrument, designed to obtain information from children and adolescents, their parents and their teachers on the symptoms of a child’s mental disorder. The new instrument includes all of the non-overlapping symptoms measured in all of the competing nomenclatures.

In the first study, interviewers from Research Triangle Institute in North Carolina will administer the interview to 1,400 children and adolescents selected to be representative of all youth living in Atlanta, Ga., and the surrounding suburban and rural counties. The responses to questions about mental-health symptoms will be analyzed using statistical techniques that identify clusters of co-occurring symptoms.

“Because no one has ever looked at all of these symptoms together, new syndromes will likely emerge,” said Lahey. Information obtained in this first study will allow researchers to examine the correlation between each putative syndrome and measures of impaired functioning in important areas of life. Those areas include problems with peers or difficulties in school, as well as suspected risk factors for mental disorders, such as unusual parenting practices.

In the second study, researchers from NORC will administer the same interview to a sample of 2,000 twin children and adolescents.

This second study will directly compare the fit of a variety of hypotheses regarding the syndromes of mental disorder to the data, testing each existing taxonomic nomenclature and any new hypotheses emerging from the first study. Because no one has ever collected data on all symptoms used in all major mental-health nomenclatures from the same group of youths, this will be the first time this critical comparative test is conducted.

“If these studies can lead to a common diagnostic language for researchers and clinicians, it will greatly improve researchers’ abilities to work together to understand mental-health problems,” he concluded. “Until we have an agreed-upon, empirically based taxonomy, we cannot hope to unravel the genetic and environmental influences on child mental-health problems.”