[Summary] Brain disorders? Precisely. Precision medicine comes to psychiatry (Insel, Cuthbert 2015)
TLDR; To create more effective treatments we need to re-name “mental” disorders as “_brain_” disorders, and shift from the DSM to newer more precise diagnosis and treatments (based in biology)
https://dacemirror.sci-hub.do/journal-article/922524f88c73c782cc07d1f7ea6cfcb3/insel2015.pdf
TLDR; To create more effective treatments we need to re-name “mental” disorders as “_brain_” disorders, shift away from old diagnostic categories (DSM), and research more precise diagnosis and treatment (based in biology).
Mental health issues are a growing world health problem and we need more effective treatments.
“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?”
We can bring precision medicine to mental health: more specific patient categorization and treatment.
“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.”
There is a gap in current neuroscience understanding and psychiatry: psychiatry diagnosis is overly subjective and nonscientific compared to most other fields of medicine, even as we learn more about the brain.
“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.”
We have enough scientific evidence to start thinking of “mental” disorders as “brain” or “neural circuit” disorders; thinking otherwise (eg that the mind is separate from the body) slows scientific research.
“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.”
The new RDoC was made to shift research toward uncovering more specific and objective measures of psychopathology.
“RDoC asks researchers to shift from designing research projects narrowly built around current diagnostic categories to dimensions or systems, such as social processes or negative valence (responding to aversive objects or situations), which are supported by a deep cognitive and neural science and can be the basis for objective measures of psychopathology.”
RDoC has already shown promising results: finding subtypes of ADHD that better respond to different treatments and biologically defined subgroups of psychotic and mood disorders.
“An early promising result from this project has emerged from studies that deconstruct current diagnostic groups to identify subgroups that have biological validity, and predict treatment response. For instance, imaging and neurophysiology have demonstrated three subtypes of attention deficit hyperactivity disorder with quite different responses to stimulant medication (9). Preliminary reports from studies using cognitive testing, imaging, and/or genomic panels are finding biologically meaningful subgroups of psychotic or mood disorders (10, 11). Notably, these biologically defined subgroups do not map neatly onto clusters of symptoms. Although these results will need replication and, most important, will need to be shown to be predictive of prognosis or treatment response, they illustrate the potential for empirically defined, convergent methods of stratifying patients. Indeed, results using information retrieval and natural language processing methods to extract RDoC dimensions from electronic health records suggest that RDoC domains, but not symptom-based diagnosis, predicted length of hospital stay or hospital readmission (12)”
Discovering specifics of brain disorders will allow us to use more precise treatments, some of which may remain talk-based psychotherapy (eg CBT), which use brain plastic it to alter circuits.
“As new diagnostics will likely be redefining “mental disorders” as “brain circuit disorders,” new therapeutics will likely focus on tuning these circuits. What is the best way to tune a negative valence or social processing circuit? Medications might be useful, but recent attention has focused on devices that invasively (deep brain stimulation) or noninvasively (transcranial magnetic stimulation) alter brain circuit activity (14). Paradoxically, one of the most powerful and precise interventions to alter such activity may be targeted psychotherapy, such as cognitive behavioral therapy, which uses the brain’s intrinsic plasticity to alter neural circuits and as a consequence, deleterious thoughts and behavior (15)”