Neuroimaging and neurophysiologic biomarkers for diagnosis and prognosis of depressive disorders, bipolar disorder, anxiety disorders, obsessive compulsive disorder, posttraumatic stress disorder, and substance use disorder: an evidence map.

backgroundAdvancements in precision medicine, particularly the use of neuroimaging and neurophysiologic techniques, may improve diagnosis, prognosis, and treatment of mental health disorders. Recent efforts to develop large neuroimaging datasets have yielded promising results for identifying mental health biomarkers. This scoping review identifies and characterizes studies of neuroimaging and neurophysiologic techniques used to address a variety of mental health disorders.

methodsWe searched MEDLINE and Embase (January 2010-September 2023). Eligible studies examined neuroimaging and neurophysiologic techniques (e.g., magnetic resonance imaging [MRI] or electroencephalogram [EEG]) for diagnosis, prognosis, and/or treatment response for eligible mental health disorders. From eligible studies, we abstracted information on populations, clinical settings, imaging techniques, study designs, outcomes, and analytic approaches.

resultsFrom 58,824 unique search results, we identified 441 eligible primary studies and 27 systematic reviews addressing mental health disorders. Most studies focused on depressive disorders (k = 320 primary studies [17 systematic reviews]); fewer examined bipolar disorders (k = 61 [3]), posttraumatic stress disorder (PTSD; k = 39 [2]), obsessive compulsive disorder (OCD; k = 26 [1]), anxiety disorders (k = 22 [3]), or substance use disorders (SUD; k = 25 [0]). Three-quarters of primary studies used MRI-based techniques and 20% employed EEG. Two-thirds of studies focused on diagnosis (nearly all cross-sectional); the remaining studies mostly addressed symptom response to various treatments, including antidepressants and psychotherapy. Most primary studies were small (N < 100; k = 263), and generally included y oung and middle-aged adults; only 5 focused on older adults (sample mean age ≥ 65). Studies were most commonly conducted in China (k = 181), the United States (k = 83), or Canada (k = 22).

conclusionsAlthough many eligible studies evaluated MRI or EEG for diagnosis and/or treatment response for depressive disorders, most were small and cross-sectional. There was less existing evidence examining other neuroimaging techniques or focusing on other mental health disorders (PTSD, OCD, anxiety disorders, or SUD). Given these evidence gaps, it is likely premature to implement neuroimaging and neurophysiologic tests in clinical settings. To determine clinical utility, future research should use large samples in longitudinal designs and investigate a broader set of disorders.

trial registrationhttps://doi.org/10.17605/OSF.IO/5PHG2 . CLINICAL TRIAL NUMBER: not applicable.