Why does stress so often precede a first psychotic episode, or a relapse? A study published in August 2026 in the American Journal of Psychiatry gives part of the answer at the level of DNA. In the brains of people who lived with schizophrenia, the gene that decides how long a stress response lasts had lost some of the chemical brakes that normally keep it quiet. The researchers' image: a speaker with the volume stuck on high.
A Gene That Sets the Length of Stress
When you face a threat, cortisol rises, does its job and should fall again. FKBP5 is the gene that regulates that shutdown: the more active it is, the less sensitive cells are to cortisol, and the longer the stress response drags on. Epigenetics, here DNA methylation, works like a dimmer on the gene: chemical tags on the DNA keep FKBP5 restrained. Since 2013 we have known that childhood trauma can strip those tags in people who carry a particular variant of the gene, and that this is linked to PTSD and depression later in life. The new study asks whether the same mechanism is at work in schizophrenia.
The Study
Katrina Edmond and Natalie Matosin at the University of Sydney, with Elisabeth Binder at the Max Planck Institute of Psychiatry, examined donated post-mortem brain tissue from two independent cohorts: 378 people who had lived with schizophrenia, major depression or bipolar disorder, and 209 controls. They looked at two regions of the frontal cortex, the dorsolateral prefrontal cortex and the orbitofrontal cortex, and combined methylation arrays, genotyping, and RNA sequencing down to the level of single cell nuclei.
The result: at several sites of the enhancer that switches FKBP5 on, methylation was lower in schizophrenia than in controls, and the lower the methylation, the higher the gene's activity. The effect was strongest in schizophrenia, weaker in depression and bipolar disorder. It depended on the person's genotype at the known risk variant, and it grew with age: the older the donor, the wider the gap.
Why It Fits
Stress is one of the best documented triggers of psychosis. Childhood adversity roughly doubles to triples the risk of later psychotic disorders, and daily stress predicts relapses. A stress response that switches off too slowly, and less and less well with age, is a plausible way for that history to become biology. It also links schizophrenia to conditions where the same gene was already implicated, PTSD and depression, without making them the same illness.
What It Does Not Show
Post-mortem tissue is a snapshot at the end of life. It cannot say whether the lost methylation came first and contributed to the illness, or appeared over years of illness, stress and treatment. Antipsychotic medication and lifestyle differences cannot be fully separated in this kind of study. And it is an association across groups, not a test: nobody can measure your FKBP5 methylation in a blood draw and tell you your risk. What the study does establish is a precise molecular target. Compounds that dampen FKBP5 exist in the lab, and the authors argue this is a lead worth pursuing, possibly for a subgroup of patients identified by genotype and age.
What It Changes For You
It gives one more reason to take early stress seriously. If you grew up with adversity, our free ACE questionnaire puts a number on it in five minutes, and our article on chronic stress and the brain covers what actually lowers a stress load. If you or someone close to you has unusual perceptions or thoughts that worry you, the free PQ-16 screening test is the questionnaire early-psychosis services use, and the SPQ test maps schizotypal traits. Both are screening tools, not diagnoses. For another recent lead on the biology of schizophrenia, see our article on the CACNA2D1 biomarker.
Sources: Edmond KZ, et al. (2026). Association Between Age-Dependent DNA Methylation Changes at FKBP5 Enhancer Sites and Increased Cortical Gene Expression in Schizophrenia. American Journal of Psychiatry; bioRxiv preprint (2025); University of Sydney via Medical Xpress (Aug 2026); Klengel T, et al. (2013). Allele-specific FKBP5 DNA demethylation mediates gene-childhood trauma interactions. Nature Neuroscience.