The DSM, the diagnostic reference used by clinicians and researchers worldwide, is set for a significant update that will, for the first time, begin folding biology into how mental illness is understood. The American Psychiatric Association has confirmed that the next edition of the Diagnostic and Statistical Manual of Mental Disorders will arrive in the coming years, with modernization through neurobiology as one of its central goals.
Since its inception, the DSM has guided how patients are diagnosed and how scientific research is organized. Yet across every edition, it has never incorporated biological measures into its diagnoses. That gap has persisted largely because the biological understanding of mental illness remained too preliminary to include in a manual with such broad clinical reach.
The current edition, the DSM-5, was released in 2013 and drew sustained criticism from both clinicians and researchers. A frequent concern was that the absence of objective biological measures risked medicalizing ordinary human suffering and weakening the validity of psychiatric diagnoses.
What biomarkers are and why psychiatry lacks them
Understanding the update requires distinguishing between two ideas. Biological factors are mechanisms that may contribute to a disease but have not yet been translated into something measurable in a lab. These can be physiological, genetic, or biochemical.
Biomarkers, by contrast, are characteristics that can be objectively measured to evaluate a biological process, including how a patient responds to treatment. They are gathered through blood tests, imaging scans, and similar methods that reveal factors tied to a specific condition. In the rest of medicine, they are routine. Hemoglobin A1C levels help diagnose and monitor diabetes, cholesterol levels indicate cardiovascular risk, and CT scans measure tumor size.
Psychiatry stands apart. There are currently no scientifically valid biomarkers for any psychiatric condition, with the exception of certain proteins used to diagnose Alzheimer’s disease. The main reason is that knowledge of the biological basis of mental disorders trails behind that of other areas of medicine.
Why the biology of mental illness is hard to measure
The biological changes that underlie mental illness are subtle, and current technologies cannot easily capture them. Serious mental illnesses are fundamentally brain disorders with substantial psychological and social components. A family history of mental illness and exposure to trauma rank among the primary risk factors for major mental disorders, and these strong environmental influences make it difficult to cleanly separate biological contributions from psychosocial ones.
There is also a conceptual challenge. Researchers do not treat psychiatric disorders as discrete illnesses but as behavioral syndromes, meaning clusters of signs and symptoms that appear together. That framing further complicates the search for clean, measurable biological markers.
Because the science is still developing, the committees working on the update chose a more nuanced approach to integrating neurobiology rather than attempting to define firm biomarkers for each condition. The subcommittee tasked with this work operated within the DSM’s strategic planning process, which ran through August 2026, as the association prepares the manual’s next edition.
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Image: arstechnica.com
