1. Centre for Mental Health Studies, University of Newcastle, Callaghan, NSW, 2308, Australia
2. Centre for Clinical Epidemiology and Biostatistics, University of Newcastle, Newcastle, Australia
3. Psychological Assistance Service, Hunter Mental Health and the Centre for Mental Health Studies, Newcastle, Australia
4. Graduate School, University of Newcastle, Newcastle, Australia
5. Hunter Mental Health and the Centre for Mental Health Studies, Newcastle, Australia