How and why psychiatrists should use imaging methods

Abstract

From the perspective of a clinical psychiatrist, the extensive research in the field of imaging methods seems to have brought virtually no relevant information to practice (except for differential diagnoses of organic mental disorders). Mental disorders have not been shown to have a correlate detectable with common methods used in other branches of clinical medicine; neither do they provide access to subjective contents, i.e., they do not allow us to "read" our patients' thoughts or emotions, as popularized, particularly, by science fiction writers. However, imaging methods do have a significant role to play in psychiatry. Along with cognitive neuroscience findings, they allow us to understand the origin of certain psychopathological phenomena and formulate specific therapeutic approaches that can be used to influence them; together with findings from histopathology and animal studies, they allow us to assess the neuropathology of mental illnesses and assess the effectiveness of treatment modalities. Imaging techniques allow us to determine which parts of the brain are connected with a particular psychopathology, which in turn allows treatment selection to be focused on the anatomical and biological targets, linked to the psychopathology, thus offering benefits to the patient. Methods are beginning to appear which, using various brain imaging and multidimensional classification techniques, allow us (with increasing sensitivity and specificity) to determine which group an assessed subject belongs. This last feature is of greatest interest in clinical practice as it may be helpful with the diagnosis (i.e., whether the image of the brain corresponds to the healthy population or the suspected disorder) or in prediction (e.g. based on response to treatment, what are the probable courses for the illness, etc.). Thus, although mental illnesses are not accompanied by specific changes in the brain perceptible to the naked eye, if we ask clinically relevant questions, imaging methods provide us with important answers. This is why psychiatrists themselves should become knowledgeable and comfortable with imaging methods.