The term diagnostic overshadowing stems from research by Steven Reiss, Grant Levitan, and Joseph Szyszko, who examined psychologists' perceptions of mental health problems in individuals with intellectual disorders (ID). Their 1982 article described their findings that the diagnosis of ID often obscured other mental health diagnoses, noting that the emotional and behavioral problems of a person with ID were attributed to limitations in cognitive and/or social functioning without further assessment, diagnosis, or treatment of comorbid conditions.

Reiss and colleagues used the term diagnostic overshadowing to describe the attribution of behavioral and emotional symptoms to the ID [Page 400]diagnosis rather than to a comorbid psychological disorder. Over time, the term has been expanded in application to other intellectual and developmental disorders (ID/DD). This entry describes ongoing research ...