A Fellow of the Royal NZ College of General Practice, Graham completed advanced training in Addiction Medicine and gained his Fellowship of the Australasian Chapter of Addiction Medicine (FAChAM) in 2008. As an Addiction Fellow he manages problems such as alcohol and drug withdrawal, naltrexone prescriptions for problem drinking, opioid substitution treatment, medication for chronic pain and he writes addiction assessments.
In 2017, Graham started the first medical cannabis service in New Zealand providing Specialist GP consultations for legal medicinal cannabis prescriptions, addressing chronic pain, cancer symptoms, anxiety, chronic insomnia and neurological conditions. He has prescribed medical cannabis to over 2500 patients with very good outcomes.
He was appointed to the Australian National Health and Medical Research Council for assessment of medicinal cannabis research projects in 2021.