Comparing the Efficacy of Heated Yoga and Sauna as a Treatment for Depression

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

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

Exclusion criteria

• Pregnant or planning to become pregnant
• Breast feeding
• Active suicidal thinking (i.e., PHQ-9 item 9 ≥1 and a positive response to C-SSRS screener items 3, 4, 5, or 6)
• Active eating disorders or substance use disorders within the past 12 months, as per the MINI
• Primary OCD or PTSD, as per the MINI
• History of bipolar disorder, psychotic disorders, as per the MINI
• ≥25% drop in PHQ-9 score from screen to baseline
• Under the influence or withdrawal of drugs or alcohol
• 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)
• have had a bone fracture or joint surgery in the past 6 months
• not able to walk freely or without difficulty
• 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+)
• 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.
• Significant exposure to heated yoga classes in the past 3 months (i.e., more than 6 classes)
• Significant exposure to sauna sessions in the past 3 months (i.e., more than 6 sessions)
• Significant exposure to mindfulness app in the past 3 months (i.e., more than 6 uses of the app)
• 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)
• antidepressant or psychiatric medications that are initiated less than 8 weeks or a dose change less than 4 weeks prior to screening visit
• psychotherapy that has been initiated within the past 3 months
• psychiatric hospitalization within the past year
• diagnosed with any neurological disorders that would impact participation or make participation unsafe
• are currently in active ketamine, Electroconvulsive therapy, or Transcranial Magnetic Stimulation treatments
• are unable to follow the study procedures (e.g., not able to travel to the heated yoga or sauna studios)
• A subject who in the opinion of the Principal Investigator would not be able to safely complete the study or would jeopardize study integrity