Landmark Study Identifies Brain-Based Biomarker for Depression Using SPECT Imaging

In a major breakthrough for mental health diagnostics, a new international study published in JAMA Psychiatry this week has uncovered a compelling brain-based biomarker for Major Depressive Disorder (MDD). The discovery could transform how depression is diagnosed and treated in the future.

The research, which included substantial data from Amen Clinics, used regional cerebral blood flow (RCBF) measurements obtained through SPECT (single-photon emission computed tomography) brain scans. These scans revealed a consistent pattern of low blood flow—known as hypoperfusion—in specific regions of the brain among individuals diagnosed with depression. This pattern was reproducible and regionally distinct, setting it apart from older approaches that relied on structural brain changes like cortical thinning, which have proven inconsistent and less clinically relevant.

"This is the strongest evidence to date that depression is not just a chemical imbalance—it's a brain imbalance you can see and measure," said Dr. Daniel Amen, founder of Amen Clinics and a co-author of the study. He emphasized that the clinic has long advocated the role of healthy cerebral blood flow in maintaining mental health, and now scientific evidence is catching up to that insight.

The study evaluated more than 15,000 participants using data from four major sources: the UK Biobank, the ENIGMA Consortium, the Amish Connectome Project, and Amen Clinics Inc. Significantly, the SPECT scan data provided by Amen Clinics closely matched newer MRI-based brain function metrics—specifically, Regional Homogeneity (ReHo) analyses. These congruent findings confirmed that reduced activity in areas like the cingulate cortex, prefrontal cortex, and temporal lobes are characteristic features of depression.

Crucially, the extent of blood flow reduction was shown to correlate directly with the severity of depressive symptoms. This suggests a promising pathway toward precision diagnostics and customized treatment plans for patients based on their unique brain function profiles.

“This validates what we've seen in over 260,000 scans: depression often involves poor brain perfusion, and when we improve blood flow, people feel and function better,” said Dr. Amen.

The findings bolster Amen Clinics’ long-standing approach, which integrates SPECT imaging into psychiatric assessment and treatment planning. This method moves beyond symptom-based diagnosis toward more objective, biological insights into mental health conditions.

The study's implications are far-reaching. By identifying a reproducible, brain-based marker for depression, the research supports the move toward imaging-informed psychiatry, where personalized care is guided by measurable brain function rather than general symptoms alone.

Amen Clinics continues to lead in the application of functional neuroimaging for mental health. Their focus remains on using brain scans not only for accurate diagnosis but also for tailoring interventions—ranging from lifestyle changes to clinical treatments—that target the root causes of psychiatric disorders.

With this study, the potential for brain imaging to inform, refine, and personalize mental health care takes a substantial step forward, offering hope for millions who suffer from depression worldwide.