• 1979–present: Consultant, University Health Service,
University of Hong Kong (HKU) • 1980–present: Consultant (Psychiatry), Hong Kong Government • 1983–present: Professor and Head, Department of Psychiatry,
University of Hong Kong (HKU) • 1983–present: Honorary Advisor, Hong Kong Mental Health Association • 1987–present: Member, Editorial Board,
Journal of the Hong Kong Medical Association • 1991–present: Member, International Editorial Board,
Journal of Stress and Depression • 1994–present: Corresponding Editor,
British Journal of Psychiatry • 1994–present: Consultant,
World Health Organization (WHO) • 1994–present: Member, Editorial Board of the Hong Kong Medical Association • 1996–present: Member, Editorial Board,
Current Opinion in Psychiatry • 1997–1999: Chairman, Hong Kong Medical Council • 1997–present: Member, Editorial Advisory Board,
Journal of Mental Health Policy and Economics • 1998–present: Chairman, Task Force on Review of Psychiatric Services • 1998–present: Member, Steering Committee on Healthcare Financing of the Hong Kong Government • 1998–2001: President, Asian Union Against Depression and Related Disorders • 1999–present: Chairman of
Queen Mary Hospital's Planning Committee • 1999–present: Member, Working Group on Quality Assurance, Medical Council of Hong Kong • 1999–present: Member, Global Forum for Health Research of the WHO/World Bank Mental Health Reform Initiative ==Notable honours/fellowships==