What are complex disorders? Schizophrenia, bipolar disorder, Alzheimer's disease and other dementias, childhood mood and attention disorders are all "complex disorders". Why "complex"? These disorders are complex in the sense that there is no single gene mutation, nor any single experience or environmental effect that can be held responsible for any of these disorders. Complex disorders = genetic effects plus development plus experience. As a consequence of complexity, and a history of focussed but isolated research strategies, present day treatments for schizophrenia and bipolar disorder are not significantly more effective than those developed 50 years ago, although side effects are less. There are still no good treatments for Alzheimer's disease. The national and indeed, worldwide burden of disease related to schizophrenia, depression and dementia is enormous. Each illness is in the top ten diseases measured by prevalence, and in the top ten measured by loss of years of healthy life to disease. The costs to society are immense, in terms of suffering of individuals and their families, and demands on the health care system. These facts must change. The proposed conference will bring researchers from multiple disciplines together to develop an integrated strategy to achieve the needed breakthroughs. This conference outcome will provide a joint base for seeking resources for research locally, nationally and internationally.