Important: A lower ACE measurement is not an established way to diagnose schizophrenia, predict treatment response, or choose a medication. Nothing here justifies changing blood-pressure drugs or psychiatric treatment.
What is new?
Johns Hopkins Medicine announced the results on October 12, 2026; the underlying peer-reviewed study appeared in JAMA Psychiatry on September 9. Researchers investigated angiotensin-converting enzyme (ACE), a protein best known for its role in blood-pressure regulation, in the context of early-stage psychosis.
The study involved 200 people: 78 controls and 122 participants with early-stage psychosis. Of those 122, 31 were classified as having treatment-resistant psychosis and 91 were not. Researchers measured ACE protein in blood and cerebrospinal fluid, examined enzyme activity and analyzed genetic information.
Observed association
ACE protein levels were lower in people with psychosis than controls and lower in the treatment-resistant subgroup than other psychosis participants. This is a group-level research finding.
Interesting biological distinction
Researchers did not find a corresponding group difference in ACE enzyme activity between treatment-resistant and non–treatment-resistant participants. They hypothesize ACE may have functions beyond blood-pressure regulation.
Why the study is preliminary
A small subgroup and a single cross-sectional measurement cannot establish diagnostic accuracy, a reliable threshold, whether ACE predicts a later response to medication, or whether ACE is causing treatment resistance. Independent, prospective studies would be required before considering any clinical assay.
ACE inhibitors are commonly prescribed for cardiovascular conditions, but the psychosis results provide no evidence to start, stop, or alter those drugs. They also do not replace clinical assessment for medication response, adverse effects, and existing specialist care pathways.
Useful questions for a care team
- How is treatment resistance currently being assessed in this individual's situation?
- Have medication effectiveness, side effects, adherence and co-occurring needs been systematically reviewed?
- Which evidence-based options and specialist supports are suitable now, separate from experimental biomarkers?
Primary sources and review notes
- Yang K, et al. Angiotensin-Converting Enzyme in Patients With Early-Stage Psychosis. JAMA Psychiatry, September 9, 2026.
- Johns Hopkins Medicine — research announcement (October 12, 2026)
Sources reviewed October 13, 2026. Exploratory research, not a diagnostic service or medical advice. Independent clinical editorial review pending.