This project explores whether heated yoga, sauna, and a mindfulness app reduce depressive symptoms

This is a parallel group study design. The investigators plan to enroll 120 adults who have at least moderate depression and will be randomized in an equal allocation ratio (i.e., 1:1:1) across three groups: heated yoga vs. sauna vs. a mindfulness app. The interventions will be provided over a 12-week period and assessments will occur at baseline (Week 0), mid-intervention (Weeks 4 & 8), post-intervention (Week 12, primary outcome), and at a 4-week (Week 16). Then participants enter an optional 1-month choice intervention period with a post-assessment (Week 20).

Subject Characteristics

Inclusion Criteria:

1. adults (18-65 years old)
2. Ability to provide informed consent
3. English language proficiency
4. PHQ-9 score > 10, indicating at least moderate depressive symptoms 21
5. Must have filled out the waiver for the community-based partners prior to enrolling in the study*
6. Individuals of childbearing potential must use an acceptable form of birth control
7. (if applicable) willingness to keep psychiatric medications and psychotherapy stable throughout the course of the study
8. Must be able to access mindfulness app on a device (i.e., smartphone, iPad, etc.)
9. Can travel to Breathe in Harvard Square and at least one Restore location (i.e., Hingham, Somerville, Dedham, Newton, Lynnfield)

Exclusion Criteria:

1. Pregnant or planning to become pregnant
2. Breast feeding
3. Active suicidal thinking (i.e., PHQ-9 item 9 ≥1 and a positive response to C-SSRS screener items 3, 4, 5, or 6)
4. Active eating disorders or substance use disorders within the past 12 months, as per the MINI
5. Primary OCD or PTSD, as per the MINI
6. History of bipolar disorder, psychotic disorders, as per the MINI
7. ≥25% drop in PHQ-9 score from screen to baseline
8. Under the influence or withdrawal of drugs or alcohol
9. Positive urine toxicology screen due to illicit drug use or other exclusionary medications. (Potential false positives will be addressed on a case-by-case basis at the discretion of the PI or designee)
10. have had a bone fracture or joint surgery in the past 6 months
11. not able to walk freely or without difficulty
12. any serious, unstable medical condition as determined by the revised Physical Activity Readiness Questionnaire (PAR-Q+) and do not have approval from their treating physician (we will check in with treating physician in the event that participants endorse any item on the PAR-Q+)
13. participants must have a healthcare provider who they could contact if they needed medical care, such as a primary care doctor, a counselor, a psychiatrist, a nurse practitioner, or a clinic that you go to.
14. Significant exposure to heated yoga classes in the past 3 months (i.e., more than 6 classes)
15. Significant exposure to sauna sessions in the past 3 months (i.e., more than 6 sessions)
16. Significant exposure to mindfulness app in the past 3 months (i.e., more than 6 uses of the app)
17. are on medications that make dehydration more likely (e.g., lithium, antipsychotics, insulin-dependent) diuretics, barbiturates, b-blockers, anticholinergics, current ETOH acute intoxication, reduced ability to sweat, hemophilia, pacemaker (magnets used to assemble saunas can interrupt the pacer)
18. antidepressant or psychiatric medications that are initiated less than 8 weeks or a dose change less than 4 weeks prior to screening visit
19. psychotherapy that has been initiated within the past 3 months
20. psychiatric hospitalization within the past year
21. diagnosed with any neurological disorders that would impact participation or make participation unsafe
22. are currently in active ketamine, Electroconvulsive therapy, or Transcranial Magnetic Stimulation treatments
23. are unable to follow the study procedures (e.g., not able to travel to the heated yoga or sauna studios)
24. A subject who in the opinion of the Principal Investigator would not be able to safely complete the study or would jeopardize study integrity