One of the hardest parts of practicing psychiatry is that we still cannot reliably predict which medication will work for which patient.
A patient comes in struggling with depression. We choose a medication based on symptoms, history, side effect profile, family history, clinical experience, and sometimes educated guesswork. Then we wait. Sometimes the medication helps quickly. Sometimes it causes side effects. Sometimes nothing happens at all. Then we adjust, augment, switch, and repeat. For many patients, this process can go on for months or even years.
If this sounds primitive compared with the rest of medicine, honestly, it is. In oncology, treatment is increasingly guided by molecular markers and individualized biology. In infectious disease, we culture organisms and test sensitivities. In cardiology, we have imaging, biomarkers, and physiologic testing. In psychiatry, we still mostly prescribe based on symptom clusters and probability.
That may slowly be starting to change.
The first wave: pharmacogenetic testing
Most clinicians have at least heard of cheek-swab pharmacogenetic testing by now. These tests look at genes involved in medication metabolism, particularly liver enzymes in the CYP450 system such as:
- CYP2D6
- CYP2C19
- CYP3A4
- CYP1A2
These enzymes help metabolize many antidepressants, antipsychotics, and benzodiazepines. Clinically, this can matter quite a bit. Some patients are poor metabolizers and may develop side effects at low doses. Others metabolize medications so rapidly that they may not reach therapeutic levels despite “normal” dosing.
We also sometimes see important gene variants involving pathways such as:
- MTHFR
- COMT
- SLC6A4
- HTR2A
These tests are not perfect, but in the right patient they can provide useful information. It does not necessarily tell us whether that medication will actually work for that patient’s brain. That is a very different question.
The next phase: beyond pharmacogenetics
One emerging precision psychiatry platform I have been following with interest is the BrightKaire test by NeuroKaire. Unlike standard cheek-swab pharmacogenetic testing, NeuroKaire uses a blood sample and induced pluripotent stem cell (iPSC) technology. In simplified terms, a patient’s blood cells are reprogrammed into stem cells and then transformed into neurons in a laboratory setting. Researchers can then study how those patient-derived neurons respond when exposed to different antidepressants. While the concept may sound futuristic, the underlying technology is rooted in legitimate advances in stem cell biology and neuroscience.
That is a major conceptual shift. Instead of asking, “How does this patient metabolize medication?” the question becomes, “How do this patient’s actual neurons respond to medication exposure?”
The platform combines:
- Neuronal response data
- Pharmacogenetics
- Computational modeling
- Clinical information
to try to identify treatments that may be more biologically compatible for a given patient.
Why this matters
Psychiatry has probably oversimplified depression and other mental health disorders for a long time. The old “chemical imbalance” explanation was never the full story. Depression is increasingly understood as involving:
- Altered neuroplasticity
- Inflammatory signaling
- Stress physiology
- Circadian disruption
- Trauma exposure
- Metabolic dysfunction
- Network-level brain changes
- Highly individualized biology
Two patients may both meet criteria for “major depressive disorder” while sharing very little underlying neurobiology. That reality helps explain why treatment response is often so unpredictable.
A necessary dose of skepticism
To be clear, these technologies are still early. Large-scale validation is ongoing. The science is evolving. Cost and accessibility remain barriers for some patients.
Psychiatry is moving toward precision medicine, but the brain remains far more complex than our current models can fully capture. No blood test replaces:
- Careful clinical assessment
- Psychotherapy
- Sleep
- Nutrition
- Movement
- Trauma work
- Social connection
- Therapeutic alliance
Human suffering is more complicated than a lab report. At the same time, I think we should also question how acceptable it is that so many patients still spend years moving through medication after medication with little biologic guidance at all.
Psychiatry is finally catching up
I do not think precision psychiatry will “solve” mental illness. But I do think psychiatry is entering a period where neuroscience, genetics, computational biology, and clinical medicine are beginning to converge in ways that may eventually improve how we match treatments to patients.
That is exciting. And frankly, overdue.
Carrie Friedman is a dual board-certified psychiatric and family nurse practitioner and the founder of Brain Garden Psychiatry in California. She integrates evidence-based psychopharmacology with functional and integrative psychiatry, emphasizing root-cause approaches that connect neuro-nutrition and gut–brain science, metabolic psychiatry, immunology, endocrinology, and mind–body lifestyle medicine. Carrie’s clinical focus bridges conventional psychiatry with holistic strategies to support mental health through nutrition, physiology, and sustainable lifestyle interventions. Her professional writing explores topics such as functional medicine, autism, provider well-being, and medical ethics.
