Garth has been working in the Alcohol and Other Drug (AOD) non-profit sector since 1980 and in executive management roles since 1986. Garth has held honorary committee and board positions as well as serving on various State Ministerial committees for NSW Health and on a National Council which directly reported to the Prime Minister of Australia.

As Executive Director of We Help Ourselves (WHOS), Garth oversees six residential AOD therapeutic communities and four day programs across NSW and Queensland. He is Chairperson (and ex Past President) of the Australasian Therapeutic Communities Association (ATCA) and Deputy President of the World Federation of Therapeutic Communities (WFTC).

Garth is an Honorary Fellow of the University of Western Sydney and in 2007 received the National Honour Roll Award (for persons who have made a significant contribution, over a considerable time period, to the Drug and Alcohol field) and the Prime Minister’s Award at the 2010 National Drug and Alcohol Awards (recognising an individual as having made a significant commitment and contribution to reducing the impact and negative effects of drug and alcohol use).

Garth‘s past board memberships and associations include Past President of the International Federation of NGOs (IFNGO), Past Co Chair and Executive Member of the Australian National Council on Drugs (ANCD), Past President and Board member of the Network of Alcohol and other Drugs Agencies (NADA) and member of the International Council of Alcohol and Addictions (ICAA).