[3] At the Maudsley, Shaffer conducted the first epidemiological study of child and early adolescent suicide using the psychological autopsy method.
He was charged by the National Institutes of Health (NIMH) to develop a child version of the Diagnostic Interview Schedule (DIS)[9] for use in large field studies.
Building on data collected as part of the Columbia Presbyterian Hospital chapter of the multi-center Collaborative Perinatal Project, Shaffer led a study of the sequelae of age-7 neurological soft signs.
[11] In that study, Shaffer and his colleagues found that neurological soft signs diagnosed at age 7 were related to mood and anxiety disorders ten years later.
Shaffer retired as director of the Division of Child and Adolescent Psychiatry at the New York State Psychiatric Institute (NYSPI)[12]/Columbia University (CU) in May 2008.