One of the most frustrating and overlooked problems in psychiatry is the way diagnostic labels are too often mistaken for causes. It’s a subtle but profound error that shapes the entire field.
Take these common examples:
“She has hallucinations because she’s schizophrenic.”
“He can’t sit still because he has ADHD.”
It sounds reasonable — even scientific. But it’s backward. In reality, a person is diagnosed with schizophrenia because they have hallucinations (and often other symptoms) of unknown cause. A person is diagnosed with ADHD because they can’t sit still. If we knew the cause — say, a viral infection, autoimmune condition, vitamin deficiency, or substance exposure — we’d call it something else. Something treatable.
The tragedy is that once the label is applied, the search for the cause often stops. The diagnosis becomes the explanation. Treatments focus on symptom management, often through medication, and we quietly accept that the person may never fully recover. Many mental health conditions are considered life-long conditions. But this assumption robs people of hope — and the possibility of healing.
The truth is that symptoms always have causes. The question is whether we’re willing to look for them.
This is where the field of functional medicine has made a meaningful contribution. Functional medicine takes a systems-based, root-cause approach to understanding illness. Instead of asking “What category does this person fit into?”, it asks, “What’s going wrong in this person’s biology, psychology, and environment that might explain their symptoms?”
This framework offers enormous promise — especially for those with treatment-resistant mental illness. I’ve seen firsthand how investigating things like mitochondrial function, metabolic health, nutrient status, gut health, and toxin exposures can lead to powerful, life-changing
interventions.
But functional medicine also has its pitfalls. In practice, many functional medicine clinicians take an overly lab-heavy approach: ordering dozens of tests that can cost thousands of dollars, and then prescribing equally extensive regimens of supplements — sometimes proprietary products that must be purchased from the clinician themselves. While some patients improve, many don’t. In those cases, they’re left not only without answers, but with lighter wallets and a growing sense of despair.
The truth is that not all root causes show up on a lab test. Often, they show up in the basics of a person’s life — in the things we’ve come to ignore or minimize because they seem too simple.
A person with insomnia, eating fast food every day, drinking a bottle of wine at night, and working 80 hours a week under chronic stress doesn’t need a $3,000 panel of specialty labs. They need help addressing the core aspects of their lifestyle — things that are absolutely biological in their effects, even if they don’t show up as a biomarker.
We must resist the temptation to make the same mistake in reverse: replacing diagnostic labels with excessive testing and supplement regimens. Instead, we need a middle path. One that values curiosity, individualization, and common sense.
The brain is part of the body. Mental symptoms are real, and they stem from real causes — whether they are metabolic, psychological, social, environmental, or some combination of all of these.
The future of psychiatry must involve rejoining the rest of medicine and reclaiming the spirit of investigation. It’s not about rejecting diagnoses or medications — but about refusing to let them be the end of the conversation.
When we stop asking why, we stop helping.
When we stay curious, healing becomes possible.
Dr. Christopher Palmer is a Harvard psychiatrist and researcher working at the interface of metabolism and mental health. He is the Founder and Director of the Metabolic and Mental Health Program and the Director of the Department of Postgraduate and Continuing Education at McLean Hospital and an Assistant Professor of Psychiatry at Harvard Medical School. For almost 30 years, he has held administrative, educational, research, and clinical roles in psychiatry at McLean and Harvard. He has been pioneering the use of the medical ketogenic diet in the treatment of psychiatric disorders—conducting research in this area, treating patients, writing, and speaking around the world on this topic. Most recently, he has proposed that mental disorders can be understood as metabolic disorders affecting the brain, which has received widespread recognition in both national and international media outlets.
