Dr Byrne is the Head of the Academy of Psychiatry within the faculty of medicine at the University of Queensland and Director of the Older Persons Mental Health Service at the Royal Brisbane Hospital and Women's Hospital. His interests include Alzheimer's disease ( particularly the neuropsychiatric symptoms assosciated with AD) and personality, anxiety and depression in older people.

Recent published work has included papers on generalised anxiety disorder in older people, dementia, and delirium in the general hospital setting and the role of lifestyle factors in predicting cognitive trajectory in middle age and later life.