In 1913 he was awarded an MD by the University of Edinburgh for his thesis "Cerebral syphilis a clinical analysis of twenty-six cases, seven with autopsy".
[2][3] The Henderson Hospital, a specialist national unit in London set up to manage and treat the now contested diagnosis of 'psychopathic' personality disorder, was named after him.
Henderson also studied for some months in Germany with a key founder of modern psychiatry, Emil Kraepelin, whom he admired but found lacking in sensitivity to patients.
Henderson's wife Margaret was also the niece of James B. Mabon banker and president of the New York Stock Exchange (May 1912-May 1914).
[12][13] The Henderson Hospital to which he gave his name evolved into a Democratic Therapeutic Community (DTC) that became an international centre of excellence for the treatment of survivors of severe trauma, before changes in healthcare funding in the United Kingdom forced its closure in 2008.