Neurobiological Foundations of Psychiatry: Overview

Mental disorders should be caused by neuropathological changes, but their symptoms appear at the level of the mind and society, and thus many types of sciences are necessary to understand them. Neurobiology refers to the natural scientific aspect of brain science. Currently, neurobiological studies have not contributed to the innovation of psychiatry and have not harmonized with evidence-based psychiatry. This would be due to ethical and technical difficulties in neurobiological studies of mental disorders. There are many unknown factors for mental disorders: molecules, brain regions, cell types, time scale, etc., which make them impossible to study in an unbiased way. To overcome such difficulties, the integration of basic and clinical studies is indispensable. Animal models in which three validity criteria are met are also important. A comprehensive exploration of responsible brain regions/neural circuits is the currently lacking, most important step of research. The recent development of spatial transcriptomics and single-cell RNA sequencing technologies would be useful for this purpose. Validation of causality by neural circuit manipulation is also an important factor. To enable such productive neurobiological research of mental disorders, mutual understanding between basic and clinical researchers is indispensable.