Dr. Barnhill's writing has focused on the psychiatric interview.

He was responsible for three chapters in "The Psychiatric Interview in Clinical Practice" (MacKinnon, Michels, and Buckley; APA Press, 2006): The Psychosomatic Patient; The Cognitively Impaired Patient; and The Hospitalized Patient.

He is on the editorial board of "Academic Psychiatry," a bi-monthly journal that focuses on psychiatric education.

He is also the editor of "Approach to the Psychiatric Patient" (APA Press) which is scheduled to published in August of 2008.