Heat and mood: what a small clinical trial tested
Researchers tested a controlled whole-body heating treatment in adults with major depression. It was a clinical treatment, not an ordinary sauna session.
The short version
In a small trial, 34 adults with major depression were randomly assigned to one session of a controlled whole-body heating treatment or to a sham treatment, and followed for six weeks. The heated group had lower depression scores than the sham group during follow-up. The result is interesting, but the trial was small: 29 people were included in the analysis. And the treatment used a device to raise body temperature, which is not the same as a sauna session.
Keep in mind
A small trial of a clinical heating treatment, not an ordinary sauna session. It is not evidence that sauna treats depression.
What they found
One week after treatment, the heated group had lower scores on a standard depression rating scale than the sham group, and the difference was still there at the six-week follow-up.
The difference held when the researchers took into account what participants expected from the treatment.
What this means for your practice
This was a clinical treatment for diagnosed depression, tested in a research trial. It is not a sauna routine, and KUUME’s rituals are not a treatment for depression.
If you are living with depression, a health professional is the right person to talk to about treatment.
Methods and limitations
What the researchers did
The researchers randomly assigned 34 adults with major depressive disorder to one of two treatments: a single session of whole-body hyperthermia, or a sham (placebo) treatment. The trial was double-blind, and symptoms were followed for six weeks.
Whole-body hyperthermia used a device to heat the whole body and raise core body temperature in a controlled way. It is a clinical procedure, not a sauna session.
Of the 34 people randomized, 30 received the treatment they were assigned and 29 were included in the analysis.
How much can this tell us?
A randomized, sham-controlled trial is a good way to test a treatment. But with 29 people in the analysis, a single small trial can easily overstate or understate an effect. Larger trials are needed before anyone can draw clinical conclusions.
At the start, the groups differed in how much they expected the treatment to help.
The trial tested one session of a controlled heating treatment. It tells us nothing about repeated sessions, other kinds of heat or ordinary sauna bathing.
What makes it useful
- Randomized, double-blind and sham-controlled
- Symptoms followed for six weeks after one session
- The result held after accounting for expectations
What limits it
- Small: 34 randomized, 29 in the analysis
- One session of a clinical heating treatment, not a sauna
- The groups expected different things at the start
Where this study fits
Where this study fits
We score claims, not single studies. This one is part of the evidence for:
Heat can ease depression. Early signal
Very low certaintyLarge effectHow you feel or perform
Read the original
Janssen CW, Lowry CA, Mehl MR, Allen JJB, Kelly KL, Gartner DE, et al. Whole-Body Hyperthermia for the Treatment of Major Depressive Disorder: A Randomized Clinical Trial. JAMA Psychiatry. 2016;73(8):789-795.
DOI 10.1001/jamapsychiatry.2016.1031 · PubMed 27172277