SMI Research Digest: Diagnosis
SMI Research Digest is a monthly publication from Treatment Advocacy Center (TAC) that summarizes recently published research on topics related to severe mental illness (SMI). This month’s Research Digest is all about diagnosis.
The utility of a schizophrenia diagnosis: In all medical settings, diagnosis is a tool for ensuring patients receive evidence-based treatment for their symptoms and achieve better outcomes. However, diagnosis based on the outward presentation of symptoms, not the underlying biology of a patient, can sometimes lead to incorrect diagnoses and delays in receiving appropriate care for people experiencing psychosis. Accordingly, it is important that diagnostic criteria are clear, understandable, and accurate. A recent review article from British Journal of Hospital Medicine highlights considerations on the utility and accuracy of a schizophrenia diagnosis. While the overlap in symptoms like psychosis and cognitive impairments with other disorders have led some to question the accuracy of a schizophrenia diagnosis, the authors note that, overall, a schizophrenia diagnosis appears to have good clinical utility, good reliability, and enables evidence-based treatment for many patients. Schizoaffective disorder has been shown to have comparatively worse reliability than related diagnoses like schizophrenia, bipolar disorder, and unipolar depression.
Recent developments in using biomarkers to diagnose schizophrenia. A 2025 systematic review article from Behavioural Neurology highlighted several new developments in our understanding of biomarkers for reliably and accurately diagnosing schizophrenia. The authors note several biomarkers including neurotransmitters, genes, neuroinflammatory processes, electroencephalography (EEG) recordings, and anatomical differences in skull height and tongue protrusion that significantly differ between people with schizophrenia and control groups. Some biomarkers may even be able to be collected using non-invasive methods like cheek swabs. However, in order to use these biomarkers to guide clinical decision making, findings must be widely reproducible, reliable, clear to interpret, and generalizable. While more research is still needed to accurately confirm or exclude a schizophrenia diagnosis based on biomarkers alone, biomarkers may still provide useful clinical insights to help providers distinguish between diagnoses. The American Psychological Association (APA) is currently considering the inclusion of biomarkers to guide diagnosis in future editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM) to help clinicians more accurately and reliably diagnose their patients.
Poorer outcomes associated with long durations of untreated psychosis. An accurate diagnosis is a pivotal first step for providing quality care and improving patient outcomes. This may be especially important given the negative outcomes associated with long durations of untreated psychosis, many of which are highlighted in a recent systemic review and meta-analysis from Schizophrenia Bulletin. The meta-analysis found that long durations of untreated psychosis were associated with more severe negative and positive symptoms, a lower rate of remission, and worse cognitive functioning. People with a long duration of untreated psychosis also had twice the odds of attempting suicide than those with a shorter duration of untreated psychosis. While more research is still needed to determine the extent to which untreated psychosis contributes to these poor outcomes, care providers should consider giving special attention to suicide prevention among patients with long durations of untreated psychosis.
SMI Research Digest is a monthly public service by TAC that highlights new, impactful research on topics related to severe mental illness. If you would like to support TAC programs and publications, please consider making a donation today.
