The theme of this symposium is the impact of brain imaging on clinical psychiatry. Brain imaging has advanced understanding of psychiatric disorders and infuenced the diagniosis of and therapies for them. Here, I focused on the impact of brain imaging on therapies in psychiatry. With recent advances in noninvasive in vivo human brain imaging（fMRI/PET）, it has become possible to investigate deep structures and molecular mechanisms in the brain. Thus, brain imaging plays an important role in understanding the mechanisms of current treatments, optimizing these treatments, and advancing them. On the other hand, with the dissemination of noninvasive human neuroimaging techniques such as fMRI, interdisciplinary neuroimaging studies on emotions and decision‒making have been accelerated. I also introduced our recent brain imaging work to assess decision‒making and possible intervention for impaired decision‒making in neuropsychiatric disorders.