Neuroimaging and Genetics

Abstract

Schizophrenia research has progressed over the years from large epidemiological studies to more specific examinations of the underlying biology of the disorder. In parallel, major leaders in psychiatry also went from thinking about schizophrenia as a psychoanalytic disorder of “the mind,” created by faulty interactions between individuals within families, to a disease with clear biologic (and thus genetic) underpinnings. The turning point in thinking emerged in the latter half of the twentieth century when Kety and Rosenthal, as well as others, published adoption studies implicating a genetic (“nature”) rather than environmental (“nurturing”) cause to the familial clustering of schizophrenia (reviewed in [1]). At the same time, the first of brain imaging methodologies was performed using computed tomography to show that the much ignored early pneumoencephalographic studies of people with schizophrenia [2] were correct in showing brain atrophy associated with the illness [3]. Thus, over the next couple of decades, both the fields of psychiatric genetics and brain imaging in psychiatry developed in parallel, but independently. There were a few scattered studies of brain structure in families, showing that changes associated with schizophrenia were likely inherited [4–6], although the studies for the most part were not brought together until candidate gene approaches emerged and some investigators had the creative idea to study both in one set of individuals, correlating brain changes to specific gene variants. The term “imaging genetics” was then coined, and investigators began meeting periodically to share these types of findings [7]. Moreover, most recently the field of schizophrenia research has moved from individual independent investigations to the joining together of large international collaborative efforts, both in genetics to perform large genome-wide association studies (GWAS), and in brain imaging to form large imaging consortia. Currently, international consortia are combining molecular genetic and MRI scanning data across centers. These advances and contributions to our knowledge about schizophrenia are reviewed in the following pages.