Guides
Antidepressants Not Working? Check Your Body Temperature
August 24, 2026 · Wilson's T3 Editorial
The idea that thyroid function and depression are connected is not Dr. Wilson’s; psychiatrists have used T3 to augment antidepressants for decades. His claim is narrower and more contested: that many people with “normal” thyroid tests and stubborn depression have a low body temperature, and that correcting it can lift the depression. This guide collects what he has written, including the case he describes in his book and the limit of what the record supports.
The accepted link, and the one he adds
If you’ve been taking an antidepressant for six weeks or more and don’t feel like you are getting much better, there’s an important link with thyroid function you should know about. A surprisingly high percentage of people with chronic or treatment-resistant depression are found to have low thyroid function, research shows. In one study, 22 % of people with treatment-resistant depression were found to have sub-par thyroid function (based on TSH levels), compared to only 2 % of people whose depression was helped by antidepressants.
I believe an even higher number of people with depression have another kind of thyroid problem that doesn’t show up on TSH tests. It’s low metabolism due to low thyroid hormone activity, and it does show up when you take your body temperature.
— When Antidepressants Don’t Work
Why he thinks temperature and mood travel together
Almost all the chemical reactions in the body are catalyzed by enzymes and enzymes depend on their shape for their activity. And, their shape depends on their temperature! Thus, when people feel bad, their temperatures can drop, and when their temperatures drop they can feel bad. This can result in people getting stuck in a vicious cycle of despair. When people get overwhelmed and feel that they are at the end of their ropes their temperatures can drop. Ironically, a low temperature itself can leave people feeling overwhelmed and at the end of their ropes.
It appears that the body has coping mechanisms that help it respond to stress. When people go through severe physical, mental, or emotional stress their bodies can slow down to conserve energy and their temperatures can drop. Apparently, this “conservation mode” helps people make it through difficult circumstances and when the difficult circumstances pass, body temperatures and body functions are supposed to come back up to normal, but sometimes they don’t.
What he says about antidepressants and T3
From the book’s page on the symptom:
The depression associated with Wilson’s Temperature Syndrome will frequently respond to antidepressants, sometimes for only two or three months, sometimes longer, and, at times, not at all. Interestingly, there have been many studies about T3 being used to enhance the effects of antidepressants – sometimes converting non-responders to a particular antidepressant into responders. It is my feeling that many of these patients’ depression would have responded to the WT3 protocol alone.
— Depression, the book
And his framing of what correcting the temperature would be doing:
Correcting low body temperature is important for depression because it actually helps to restore normal neurotransmitter production in your brain. Instead of treating symptoms, as drugs do, it is correcting the cause. Low body temperature can be corrected with proper thyroid support, which often includes a trial of T3.
— When Antidepressants Don’t Work
That “correcting the cause” sentence is the claim the critics reject, and it is presented here as his.
The case in the book
One such patient that I have treated developed significant depression approximately 25 years ago. Since then it has plagued, shaped, and colored her entire life. It contributed to her getting a divorce and it became so severe and debilitating at one point almost 20 years ago, that it caused her to feel constrained to give up custody of her children, thinking that they might be better cared for by someone else. The various antidepressants with which she has been treated over the years did help some, but did not provide her with satisfactory improvement. The complete resolution that came within two weeks of weaning her antidepressant medication and beginning the WT3 protocol, was bittersweet.
— Depression, the book
A single case, told by the treating physician. It is the kind of account the book is made of, and it is not a trial.
Which symptoms he finds most responsive
The doctor’s manual ranks depression among the symptoms he finds most gratifying to treat — and explains why:
Some of the most gratifying symptoms to treat include migraines, PMS, panic attacks, and depression. These symptoms have two things in common. First, they are among the most debilitating of complaints, and secondly, they are among the most typically responsive to T3 therapy.
— Caveats for T3 Therapy, the doctor’s manual
The step he asks for
People whose body temperature is consistently below 97.8 F. (36.56 C.) are likely to have this problem, called Wilson’s Temperature Syndrome (WTS). They may have trouble converting T4, the inactive form of thyroid hormone, to T3, the active form. Many doctors are not aware that this syndrome exists; or they discount its widespread prevalence. Most certainly do not check for it.
— When Antidepressants Don’t Work
Take it properly — three daytime oral readings, averaged, several days (how) — and bring the log to the doctor who prescribes your antidepressant. Do not stop an antidepressant on your own; the case above involved a physician weaning one drug while starting another, under supervision. He also recommends the ordinary things: “Regular aerobic exercise is also a good way to lift your mood, and works well with T3 therapy.”
Where this sits in the evidence
The published record on the protocol is an eleven-patient report and a clinical-experience paper, neither of them a trial of depression outcomes (the record, as described on the author page). Wilson’s Temperature Syndrome is not accepted by every medical body. If depression is severe, or there is any thought of self-harm, that is an emergency and none of this applies — get help now.
More on the site: Depression, Anxiety, Panic Attacks, Mood, energy and sleep — the hub, and Find a practitioner.
This is a reader’s guide compiled from Dr. Wilson’s published writing; every quotation is his and links to its source. It is not medical advice.