After 3 years in the US, he returned in 1986 to the QIMR Berghofer where he heads the Genetic Epidemiology Laboratory and continues longitudinal studies with twins of a wide range of complex traits of medical and behavioural interest. Professor Martin is involved in several large studies of cognition and brain imaging (EEG and MRI). His research over recent years has moved to genome wide association studies (GWAS) to locate genes influencing complex traits including anxiety, alcoholism, and dizygotic twinning. He developed methods for multivariate analyses and the analysis of gene-environment interactions. Most recently Professor Martin has initiated projects to recruit large patient samples for GWAS of anorexia, depression and other psychiatric disorders. He has published over 1200 papers and is a fellow of the Australian academies of Science, Social Science, and Health and Medical Science.