A former DSM committee member has said the next edition of psychiatry's diagnostic manual will describe the biology behind each disorder. A Patna neuropsychiatrist explains what will and will not change, walks through the Alzheimer's blood test, the schizophrenia and depression genetics and the imaging subtypes, and sets out what it means for patients and families today.
In this article 10
- Why psychiatric diagnosis has been different from the rest of medicine
- What the DSM-6 will actually change
- The one real blood test: Alzheimer's disease
- The wider evidence: psychiatric diagnosis is becoming more valid
- The immune connection: depression and inflammation
- Genetics without a genetic test
- What this means for patients and families today
- Frequently Asked Questions
- References
- About this article
In one line
Biological markers in psychiatric diagnosis: for seventy years a psychiatric diagnosis has rested on what a patient says and a clinician observes. No blood test, no scan. That is about to change: slowly, carefully, and not in the way the headlines suggest. The next edition of the Diagnostic and Statistical Manual of Mental Disorders, the DSM-6, is set to admit biology into the book for the first time. Here is what that means, and why it is part of a longer story about psychiatry becoming a more exact science.1
Why psychiatric diagnosis has been different from the rest of medicine
When a patient in Patna comes to me with chest pain, a cardiologist down the corridor can order a troponin level and an ECG and say, with confidence, whether the heart muscle is injured. When the same patient comes to me with three months of low mood, poor sleep and a wish not to wake up, I have no equivalent test. I ask questions. I watch. I apply criteria written by committees. The diagnosis of major depression is real (it predicts course, it guides treatment, it saves lives), but it is made the way medicine made diagnoses before the laboratory existed.
This is the gap that has haunted psychiatry's reputation. Families ask, reasonably, "Is there a test?" Sceptics ask whether the categories exist at all. And clinicians, honestly, have sometimes wondered the same.
On 2 November 2026 Live Science published an interview with Dr Anand Kumar, Head of Psychiatry at the University of Illinois Chicago and a former member of the DSM Strategy Committee, on how the DSM-6 plans to begin closing that gap.1 I have read it alongside the research it rests on, and alongside several other developments of the past four years that point the same way.
Before you read
This article describes a planned change to a diagnostic manual and the research behind it. With one exception noted below, no blood test or scan can currently diagnose a psychiatric condition, and no such test is offered at Healthy Minds India. Diagnosis remains clinical.
Key takeaways · DSM-6 and biological markers
- The DSM-6 will, for the first time, describe biological factors (genetics, immune and inflammatory pathways) alongside clinical criteria. Diagnosis will still be made clinically.
- Only one condition in the manual's territory currently has a validated blood test: Alzheimer's disease, where the US FDA cleared a plasma test in May 2025.
- For depression, schizophrenia and anxiety, hundreds of genetic risk variants are now firmly established, and immune dysfunction explains a substantial minority of depression. Neither has become a laboratory test.
- The direction of travel is clear: psychiatric diagnoses are being anchored to measurable biology, step by step, the way heart disease and diabetes were a generation ago.
What the DSM-6 will actually change
Dr Kumar is careful, and I will be too. The change is not that psychiatrists will order a test and read off a diagnosis. The change is that the manual will, for the first time, state what is known about the biology behind each category (the genetic architecture, the immune and inflammatory pathways, the brain circuits) as part of the disorder's description.
He draws a distinction worth remembering. A biomarker is a measurement you can order: a blood level, a scan finding, with a cut-off, validated against outcomes. A biological factor is a mechanism known to contribute to a disorder but not yet crystallised into a test. Outside Alzheimer's disease, he says plainly, psychiatry has the second kind and not the first. The DSM-6 will describe biological factors; it will not, for most conditions, prescribe biomarkers.1
Why do it at all, then? Three reasons emerge from the interview.
It describes the disorders more honestly. A clinician reading that depression carries a polygenic risk, that around a third of cases show immune activation, and that the condition shares genetic ground with anxiety, has a fuller picture than a checklist of nine symptoms provides.
It explains comorbidity. Roughly 45 per cent of people with a mood disorder also have an anxiety disorder, and the reverse is equally true. Dr Kumar's point is that this is not coincidence; these conditions share genes. Writing that into the manual tells clinicians to look for both and to treat more broadly. (Our guide to generalized anxiety disorder explains how the two overlap in practice.)
It aligns psychiatry with the rest of medicine. No cardiologist diagnoses heart disease from a single gene. They build a risk profile from genes, blood pressure, lipids, weight, smoking and family history. Psychiatry has lacked that layered model. The DSM-6 is an attempt to begin building it.
Dr Kumar's own description of the step is that it moves the field forward conceptually rather than incrementally, and he hedges even that with the acknowledgement that it will not be perfect and will not please everyone.
The one real blood test: Alzheimer's disease
The headline of the Live Science piece ("now you actually have a blood test") refers to one condition only, and it is worth seeing why it is the exception.
Alzheimer's disease is defined by two proteins that accumulate in the brain: amyloid and tau. For twenty years those could be measured only by PET scanning or by lumbar puncture. On 16 May 2025 the US Food and Drug Administration cleared the first blood test, which measures the ratio of phosphorylated tau-217 to amyloid-beta 1-42 in plasma. In the study submitted to the regulator, 499 cognitively impaired adults were tested; among those with a positive result, about 92 per cent had amyloid plaques confirmed on PET or spinal fluid, and among those with a negative result, about 97 per cent were confirmed negative.2
The consequence is a genuine shift in definition. As Dr Kumar describes it, a patient with cognitive decline on examination must now have a positive biomarker to be classed as having definite Alzheimer's disease.1 The diagnosis has acquired a laboratory anchor. That is what a biomarker looks like when it arrives, and it arrived because the underlying biology (two specific proteins) was simple enough to measure. (Our page on dementia and memory assessment explains how memory problems are evaluated today.)
Depression and schizophrenia are not like that. There is no single protein. There are hundreds of genes, several immune pathways and many circuits. The absence of a blood test for them is not a failure of effort; it reflects the kind of conditions they are.
The wider evidence: psychiatric diagnosis is becoming more valid
The DSM-6 change does not stand alone. Over the past few years a series of findings, each reported in the scientific and general press, have moved psychiatric categories from pure description towards measured biology. I have collected the ones that matter most, with their sources.
| Year | Finding | What it shows about validity |
|---|---|---|
| 2022 · Nature | The Psychiatric Genomics Consortium analysed 76,755 people with schizophrenia and 243,649 without, identifying 287 regions of the genome linked to the condition, concentrated in genes active in brain neurons.3 A companion study found rare damaging mutations in ten genes that raise risk several-fold, in some cases 20- to 50-fold.4 | Schizophrenia has a reproducible genetic signature pointing to synaptic biology: the strongest evidence yet that the clinical category maps onto a biological one. |
| 2024 · Nature Medicine | A Stanford team led by Leanne Williams used functional brain imaging in about 800 people to identify six distinct "biotypes" of depression and anxiety, each with a different circuit pattern and different responses to treatment.5 | Depression is not one thing; brain imaging can begin to separate subtypes that symptoms alone cannot. |
| 2025 · Cell | The largest genetic study of depression, in 688,808 people with the condition and more than 4.3 million without, across major world ancestries, identified 697 genetic associations (293 of them new) implicating 308 genes, enriched in neurons including those of the amygdala, a region central to emotion.6 | Major depression has a measurable polygenic architecture that holds across ethnicities, including South Asian populations. |
| 2025 · US FDA | Clearance of the first plasma blood test for Alzheimer's disease pathology, replacing PET or lumbar puncture for many patients.2 | The first psychiatric-neurological diagnosis in the DSM's territory to acquire a laboratory biomarker. |
| 2026 · Science Advances | A McGill study of 50 people found that a weakened beta-band brain rhythm, measured by magnetoencephalography, tracked three separate schizophrenia symptoms: perception, speech and overall severity.7 (Covered in this series as No. 07, One Rhythm, Many Symptoms.) | Symptoms that look unrelated share a measurable physiological signal: a candidate marker for earlier detection, pending replication. |
| 2026 · Live Science | The DSM-6 will incorporate biological factors (genetic, immune, inflammatory) into its descriptions of disorders.1 | The profession's own manual formally acknowledges the biological basis of its categories. |
A pattern runs through the table. Genetics has moved from "it runs in families" to specific, replicated loci. Imaging has moved from average group differences to subtypes with treatment implications. Physiology has produced candidate signals. And in the one condition with simple enough biology, a blood test has arrived. Psychiatric diagnoses are not becoming less real as science advances; they are becoming more precisely described.
The immune connection: depression and inflammation
One biological factor deserves its own section because it comes closest to clinical use. Dr Kumar cites immunology as a pathway shown to matter in about 30 per cent of major depression.1 That figure comes from a decade of work showing that a substantial subgroup of depressed patients have raised inflammatory markers (C-reactive protein, interleukin-6 and others) and that this subgroup tends to respond poorly to standard antidepressants and better to treatments with anti-inflammatory action.8,9
Why is this not yet a test? Because the cut-offs are not agreed, because inflammation has many other causes, and because the trials of anti-inflammatory treatment have been mixed. It is a factor, not a marker. But it is the kind of factor that could become a marker within a decade, and it already shapes how thoughtful clinicians think about a patient whose depression will not shift. (See our page on depression treatment in Patna.)
Genetics without a genetic test
The public idea of genetics is one gene, one disease. Psychiatric genetics is nothing like that. The 697 associations linked to depression and the 287 loci linked to schizophrenia each raise risk by a tiny fraction; most people carry many of them, and most of those people are well. Risk accumulates, interacts with environment (early adversity, substance use, stress) and tips some people over.3,6
This is why there is no genetic test for depression and why, in my view, there should not be one marketed to the public any time soon. A "polygenic risk score" can rank people by genetic liability, and research uses this productively, but at the individual level it cannot say who will become ill. What the science does establish, beyond argument, is that these conditions have a biological basis as real as that of diabetes. The DSM-6 will say so. For families in Bihar who still hear that depression is weakness, or that schizophrenia is possession, that sentence in the profession's own manual matters.
Dr. Saurabh's note
I am wary of two opposite errors. The first is the old one: that psychiatric illness is not "real" because there is no test. The second is new: the laboratory that will, within a year, advertise a "depression gene panel" or an "inflammation profile for mental health" on the strength of articles like this one. Neither is justified. The science is advancing; the tests are not here; and the diagnosis, as Dr Kumar says, remains clinical.
What this means for patients and families today
Your diagnosis is not guesswork. A clinical diagnosis made carefully, from history and examination, against criteria refined over decades, is a valid medical act. The biology now being described underneath it confirms rather than replaces it. (Our assessment and diagnostic services page explains what a full psychiatric evaluation involves.)
Family history matters more than you think. Tell your psychiatrist about relatives with depression, psychosis, addiction or suicide. It is the most useful "genetic test" currently available.
Comorbidity is expected, not a complication. If you have depression, anxiety is likely; if you have anxiety, watch for substance use. Shared biology means shared vigilance.
Be sceptical of tests sold directly. No blood test, gene panel or brain scan currently diagnoses depression, anxiety, ADHD, bipolar disorder or schizophrenia. Any clinic offering one is ahead of the evidence. The Alzheimer's blood test is the exception, and even that is cleared only for people over 55 with cognitive symptoms, interpreted alongside clinical assessment.2
Expect the manual to change gradually. The DSM-6 does not yet have a publication date. When it appears, it will describe biology; it will not hand clinicians a laboratory menu. Treatment decisions will still rest on the conversation in the consulting room.
More from the Awareness Series
Your questions
Frequently Asked Questions
Is there a blood test for depression?
No. Research has identified inflammatory and genetic factors associated with depression, but none has been validated as a diagnostic test. Any such test offered commercially today is not evidence-based.
What is the DSM, and why does it matter in India?
The DSM is the American Psychiatric Association's diagnostic manual, used worldwide in research and widely in clinical practice alongside the WHO's ICD system. Indian psychiatry uses both; changes to the DSM shape training, research and, over time, practice here too.
Will the DSM-6 require genetic testing?
No. According to Dr Kumar, genetics will be described as a contributing factor, not introduced as a test. Diagnosis will remain clinical.
Can a brain scan diagnose schizophrenia or bipolar disorder?
Not at present. Imaging studies find average differences between groups and, increasingly, subtypes, but no scan can confirm or exclude a diagnosis in an individual.
Does the Alzheimer's blood test work for all memory problems?
It detects amyloid pathology in people over 55 who already have cognitive symptoms. It does not screen healthy people and does not diagnose other dementias or depression-related memory complaints.
If psychiatric illness is biological, is psychotherapy still useful?
Entirely. Biology and environment interact; therapy changes brain function measurably. A biological basis for a condition does not imply a purely biological treatment, any more than it does for heart disease, where diet and exercise remain central.
References
Prompted by Kenna Hughes-Castleberry, "'Now you actually have a blood test': Psychiatry's bible, the DSM, is getting upgraded to include biological markers", Live Science, 2 November 2026 (interview with Dr Anand Kumar). This article is written in my own words; the interview is paraphrased with attribution. Study details were checked against the publisher records.
- Hughes-Castleberry K. 'Now you actually have a blood test': Psychiatry's bible, the DSM, is getting upgraded to include biological markers. A psychiatrist explains what that means for mental health. Live Science, 2 November 2026. Interview with Dr Anand Kumar, University of Illinois Chicago. livescience.com. Used for: DSM-6 plans, biomarker vs biological factor, comorbidity figures and the immune share of depression.
- US Food and Drug Administration. FDA clears first blood test used in diagnosing Alzheimer's disease. Press release, 16 May 2025 (Lumipulse G pTau217/β-Amyloid 1-42 Plasma Ratio). Used for: the Alzheimer's blood test, its accuracy figures and intended use.
- Trubetskoy V, Pardiñas AF, Qi T, et al. Mapping genomic loci implicates genes and synaptic biology in schizophrenia. Nature. 2022;604(7906):502-508. doi:10.1038/s41586-022-04434-5. Used for: 287 schizophrenia loci.
- Singh T, Poterba T, Curtis D, et al. Rare coding variants in ten genes confer substantial risk for schizophrenia. Nature. 2022;604(7906):509-516. doi:10.1038/s41586-022-04556-w. Used for: rare high-impact variants.
- Tozzi L, Zhang X, Pines A, et al. Personalized brain circuit scores identify clinically distinct biotypes in depression and anxiety. Nature Medicine. 2024;30(7):2076-2087. doi:10.1038/s41591-024-03057-9. Used for: imaging-defined depression biotypes.
- Adams MJ, Streit F, Meng X, et al. Trans-ancestry genome-wide study of depression identifies 697 associations implicating cell types and pharmacotherapies. Cell. 2025;188(3):640-652. doi:10.1016/j.cell.2024.12.002. Used for: depression genetics across ancestries.
- Wei HT, Boutet D, Dou R, et al. Neurophysiological dynamics related to perception, action, and language in schizophrenia. Science Advances. 2026;12(43):eaeh5819. doi:10.1126/sciadv.aeh5819. Covered in this series as Awareness No. 07. Used for: the beta-band signal in schizophrenia.
- Osimo EF, Baxter LJ, Lewis G, et al. Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels. Psychological Medicine. 2019;49(12):1958-1970. doi:10.1017/S0033291719001454. Used for: the inflammatory subgroup of depression.
- Miller AH, Raison CL. The role of inflammation in depression: from evolutionary imperative to modern treatment target. Nature Reviews Immunology. 2016;16(1):22-34. doi:10.1038/nri.2015.5. Used for: inflammation and treatment response in depression.
About this article
Written and medically reviewed by
- MD (Psychiatry) AIIMS New Delhi
- Associate Professor & HOD, Dept. of Psychiatry, RDJM Medical College, Muzaffarpur
- Ex-Assistant Professor, PMCH Patna
- Consultant, Healthy Minds India, Patna
- Written
- November 2026
- Format
- Research explained
- Evidence
- Published interview with a former DSM committee member, an FDA clearance and large peer-reviewed genetic and imaging studies; statements about the DSM-6 may change before publication
- Sources
- 9 references
- Statements about the DSM-6 reflect a published interview with a former committee member and may change before the manual is published.
- Dr. Saurabh Kumar's research focuses on brain stimulation treatments in psychiatry. He is the author of The Indian Mind.
© 2026 Healthy Minds India, Patna · Research explained, October 2026
Disclaimer
This article is for general awareness. Statements about the DSM-6 reflect a published interview with a former committee member and may change before publication of the manual. No blood test, gene panel or brain scan for a psychiatric condition is offered at Healthy Minds India. Nothing here replaces assessment by a qualified psychiatrist. Healthy Minds India is not an emergency service.
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Medically reviewed by Dr. Saurabh Kumar, Consultant Neuropsychiatrist, Healthy Minds India, Patna. This article is for general education and is not a substitute for a personal consultation. To discuss your situation, book an appointment or contact the clinic.
