Sauna for psychotic disorders (schizophrenia spectrum)
Evidence review
Overview
In the Kuopio (KIHD) cohort of middle-aged Finnish men, frequent sauna bathing was associated with a markedly lower risk of later hospital-diagnosed psychotic disorders, independent of fitness and other measured factors. Both reports come from the same cohort, involve men only, and address prevention of new illness rather than treatment of established illness. No interventional study of sauna or heat therapy in people with schizophrenia or other psychotic disorders was found.
Key findings
- 4-7 vs 1 session/week: psychosis HR 0.21 (95% CI 0.08-0.52), multivariable (Laukkanen 2018, n=2,138)
- 3-7 vs <=2 sessions/week: psychosis HR 0.49 (0.32-0.74), 0.50 (0.33-0.75) after fitness adjustment (Kunutsor 2024, n=2,221, same cohort)
Every study we reviewed
2 found benefit
Each study was checked on PubMed. The colored edge shows the direction of the result. The research library lists 3 studies on psychotic disorders, across all heat and cold therapies, including case reports and older work not graded here.
Sauna Bathing and Risk of Psychotic Disorders: A Prospective Cohort Study.
Laukkanen T et al. Med Princ Pract. 2018. PubMed 30173212 · DOI · Free full text
- Who
- Finnish men aged 42-61 without psychotic disorder (KIHD)
- What
- self-reported sauna frequency, 2-3 or 4-7 vs 1 session/week
- Protocol
- 1 vs 2-3 vs 4-7/wk
- Measured
- incident psychotic disorders
- Result
- 4-7 vs 1 session/week: HR 0.23 (95% CI 0.09-0.58) age-adjusted; 0.21 (0.08-0.52) multivariable; 0.23 (0.09-0.57) after adjustment for session duration and temperature. 203 cases over median 24.9 years.
- Limitations
- observational; men only; only 184 men in the 4-7/week group; incidence, not treatment; residual confounding possible
Frequent sauna bathing and psychosis: Interrelationship with cardiorespiratory fitness.
Kunutsor SK et al. J Psychiatr Res. 2024. PubMed 38718442 · DOI · Free full text
- Who
- Finnish men aged 42-61 without psychosis (KIHD)
- What
- self-reported sauna frequency, 3-7 vs <=2 sessions/week, with measured cardiorespiratory fitness
- Protocol
- <=2 vs 3-7/wk
- Measured
- incident psychotic disorders
- Result
- High vs low sauna frequency: HR 0.49 (95% CI 0.32-0.74); 0.50 (0.33-0.75) after adjustment for cardiorespiratory fitness. 215 cases over median 25.2 years.
- Limitations
- same cohort as Laukkanen 2018 (not independent replication); observational; men only
Protocols used in the studies
Cohort exposure was ordinary Finnish sauna use, classified by sessions per week. There are no interventional protocols in this population.
What is still unknown
Whether any effect exists in people with established psychotic disorders; safety with antipsychotic and anticholinergic medication; replication outside one male Finnish cohort.
Safety
Cautions for sauna in this condition
- Antipsychotics can impair thermoregulation; heatstroke complicated by olanzapine use has been reported (case report, PMID 31157624).
- In people with severe mental illness, heatwaves were associated with more heat-related illness whether or not antipsychotics were prescribed (IRR 1.48 vs 1.45) (PMID 39648665).
- Clinical stability, supervision and hydration should be considered; see general-safety.
For clinicians
Suggested rationale
In a prospective Finnish cohort (Laukkanen 2018), men who used the sauna 4-7 times per week had a lower risk of developing a psychotic disorder (HR 0.21 vs once weekly), but this is observational data on new-onset illness and does not establish benefit for a patient who already has a psychotic disorder.
Suggested wording only. The treating clinician decides whether it reflects their clinical judgment for this patient.
Typical ICD-10 codes: F20.9, F29. Examples only; the clinician assigns the code.
What a letter of medical necessity should containWho can write it: physicians, NPs, PAs and others