He is a member of the Australian Suicide Prevention Advisory Council and the Queensland Advisory Group on Suicide (QAGS). He is co-founder of the Italian Society for PsychoOncology. De Leo is the author of scientific articles and books. His most recent volumes are "Turning Points" (2011), and "Bereavement after Traumatic Deaths" (2013). He is the founder and previous Editor-in-Chief of the "Italian Journal of Suicidology", previous Editor-in-Chief of "Crisis: The Journal of Crisis Intervention and Suicide Prevention", Editor-in-Chief of the "Open Journal of Medical Psychology" and editor of "Suicide Research: Selected Readings". De Leo is married to Cristina Trevisan, an interior decorator and modern art expert. They had two sons, both killed in a road accident in Italy in 2005.