Professor Clarke is the Head of Consultation-Liaison and Primary Care Psychiatry at Southern Health. His particular interest and expertise is in the area of depression, depression in the presence of physical illness, and psychological factors contributing to physical illness (or psychosomatics). His original research has been to define more clearly the nature of depressive subtypes seen in people with physical illness and in those presenting in primary care settings. As well as his role at Southern Health, and as Professor within the Discipline of Psychological Medicine at Monash University, Professor Clarke is Research Advisor to beyondblue: the national depression initiative.