Mental disorders represent a public health challenge of staggering proportions. In the most recent Global Burden of Disease study, mental and substance abuse disorders constitute the leading source of years lost to disability from all medical causes (1). The World Health Organization estimates over 800,000 suicides each year globally, nearly all of which are a consequence of a mental disorder (2). These high morbidity and mortality figures speak to the potential for overall health gains if mental disorders can be more effectively diagnosed and treated. Could a “precision medicine” approach find traction here?
Precision medicine—a more targeted approach to disease—is already becoming a reality in cancer, where molecular diagnosis is leading to better defined, individualized treatments with improved outcomes (3). Precision medicine is also the basis for planning large-cohort studies, using genomics and phenotyping (physiological and behavioral characteristics) to improve diagnostics and therapeutics across medicine. The idea is to integrate clinical data with other patient information to uncover disease subtypes and improve the accuracy with which patients are categorized and treated.
Diagnosis in psychiatry, in contrast to most of medicine, remains restricted to subjective symptoms and observable signs. Clinicians rightly pride themselves on their empathic listening and well-honed observational skills. But recently psychiatry has undergone a tectonic shift as the intellectual foundation of the discipline begins to incorporate the concepts of modern biology, especially contemporary cognitive, affective, and social neuroscience. As these rapidly evolving sciences yield new insights into the neural basis of normal and abnormal behavior, syndromes once considered exclusively as “mental” are being reconsidered as “brain” disorders—or, to be more precise, as syndromes of disrupted neural, cognitive, and behavioral systems.
But before research on the convergence of biology and behavior can deliver on the promise of precision medicine for mental disorders, the field must address the imprecise concepts that constrain both research and practice. Labels like “behavioral health disorders” or “mental disorders” or the awkwardly euphemistic “mental health conditions,” when juxtaposed against brain science, invite continual recapitulation of the fruitless “mind-body” and “nature-nurture” debates that have impeded a deep understanding of psychopathology. The brain continually rewires itself and changes gene expression as a function of learning and life events. And the brain is organized around tightly regulated circuits that subserve perception, motivation, cognition, emotion, and social behavior. Thus, it is imperative to include measures of both brain and behavior to understand the various aspects of dysfunction associated with disorders. Shifting from the language of “mental disorders” to “brain disorders” or “neural circuit disorders” may seem premature, but recognizing the need to incorporate more than subjective reports or observable behavior in our diagnosis of these illnesses is long overdue.