Dr. Robert L. Spitzer is a retired Professor of Psychiatry at Columbia University in New York City, United States. He was chair of the task force of the third edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-III) which was released in 1980. He has been referred to as a major architect of the modern classification of mental disorders which involves classifying mental disorders in discrete categories, with specified diagnostic criteria.