A new study just published in Biological Psychiatry introduces the possibility of objective biological tests for psychiatric disorders and outlines data-driven analysis tools that improve upon the limited usefulness of the Diagnostic and Statistical Manual of Mental Disorders (DSM) in biological research of psychiatric disease. Moving beyond the category-based “silos” imposed by the DSM is a focus of the National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC) Project, which seeks to reconceptualize the diagnostic system based on objective neuroscience findings.
“Data-Driven Phenotypic Categorization for Neurobiological Analysts: Beyond DSM-5 Labels” reports the findings of an analysis of 347 individuals both with and without a history of mental illness. Putting aside DSM labels, the authors first developed behavioral profiles for each individual based upon six dimensions of behavior, personality and psychiatric symptomatology. The researchers then grouped participants into behavioral “communities” based upon similarities in these profiles. Within communities, they also identified eight sub-communities, groups of participants with even stronger behavioral similarities. Importantly, the differences between the communities were readily detectable from the behavioral profiles derived in the work. Four of the groups contained typical or psychologically well-adapted individuals; identifying distinctions in these healthy subgroups is impossible for clinically focused DSM approaches.
The groups identified through data-driven analysis mapped onto measurable differences in brain function, revealed with neuroimaging (MRI) technology. Group comparisons revealed significant differences in brain connectivity, particularly in the somatomotor, thalamic, basal ganglia and limbic networks.
Dr. Nicholas T. Van Dam, post-doctoral fellow at the Icahn School of Medicine, is the lead author; Dr. Michael P. Milham, director of the Center for the Developing Brain at the Child Mind Institute, director of the Healthy Brain Network and director of the Center for Biomedical Imaging and Neuromodulation at the Nathan S. Kline Institute for Psychiatric Research, is the senior and corresponding author.
“This research helps to define a direction for future imaging and genetics research, as biological psychiatry works towards the holy grail of biological psychiatry—objective diagnosis through tests including brain imaging,” said Harold S. Koplewicz, MD, founding president of the Child Mind Institute. “And while we certainly welcome the possibility of MRI-assisted diagnosis and assessment in the future, having a study now that shows how real brain differences underlie mental health disorders will have a revolutionary effect on access to care and public opinion.”
The study made use of behavioral information, psychiatric assessment and resting state functional magnetic resonance imaging (R-fMRI) obtained through the Nathan Kline Institute-Rockland Sample (NKI-RS). The NKI-RS, founded by Dr. Milham with the support of Dr. Koplewicz, has become a model for pre-publication open data sharing in the brain imaging community. All the data used in the study carried out by Drs. Van Dam and Milham can easily be obtained by other investigators around the world, who can in turn work to replicate and extend their work.
“Psychiatry has been limited by the lack of objective biological tests and the overlapping, subjective nature of psychiatric diagnosis,” said Dr. Milham. “MRI methodologies will eventually deliver on the promise of brain-based markers of mental illness. However, as highlighted by RDoc and demonstrated by this study, researchers must give equal attention to behavioral, psychiatric and medical information, as maturing imaging methodologies will continue to depend upon phenotypic data for clinically relevant analysis and diagnosis.”
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The Child Mind Institute is an independent nonprofit dedicated to transforming the lives of children and families struggling with mental health and learning disorders. Our teams work every day to deliver the highest standards of care, advance the science of the developing brain, and empower parents, professionals and policymakers with resources to support children when and where they need it most. Together with our supporters, we’re helping children reach their full potential in school and in life. We share all of our resources freely and do not accept any funding from the pharmaceutical industry. Learn more at childmind.org.