This study will examine how doing heated yoga or non-heated yoga affects depression.

The purpose of this study is to investigate the effects of heated and non-heated yoga on depressive symptoms. Previous research trials using heated and non-heated yoga interventions have shown promising results for reducing depression and its related outcomes. However, no studies have directly compared the effects of heated vs. non-heated yoga for depression. The researchers aim to address this gap by conducting a non-inferiority trial comparing heated yoga and non-heated yoga interventions to improve depressive symptoms. Both the heated and non-heated yoga interventions will be conducted in-person by certified yoga instructors. Eligible participants will be adults who do not regularly practice yoga or meditation and are experiencing moderate levels of depression. Assessments will be conducted at baseline, mid-treatment, post-treatment, and follow-up using a secure data capture system.

Inclusion Criteria:

1. adults (18-65 years old)
2. able to provide consent
3. are able to read and understand English
4. PHQ-9 score between 10-20, indicating moderate but not severe depressive symptom severity (27)
5. Must have filled out the waiver for the community-based yoga studio prior to enrolling in the study.

Exclusion Criteria:

1. have had a bone fracture or joint surgery in the past 6 months
2. not able to walk freely or without difficulty
3. have severe heart failure or lung disease
4. participants endorse an item on 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+)
5. participants must have a physician responsible for their medical care
6. are pregnant or planning to become pregnant
7. no more than 6 yoga classes in the past 6 months
8. have active suicidal thinking (i.e., PHQ-9 item 9 ≥1 and a positive response to C-SSRS screener items 3, 4, 5, or 6)
9. report manic symptoms (Altman Self-Rating Mania Scale score ≥ 6 (28))
10. are on medications that make dehydration more likely (e.g., lithium, antipsychotics, insulin-dependent)
11. active eating disorders or substance use disorders within the past 12 months
12. antidepressant or psychiatric medications that are initiated less than 8 weeks or a dose change less than 4 weeks prior to screening visit
13. psychotherapy that has been initiated within the past 3 months
14. willingness to keep psychiatric medications and psychotherapy stable throughout the course of the study
15. psychiatric hospitalization within the past year
16. diagnosed with any neurological disorders that would impact participation or make participation unsafe
17. are currently in any active ketamine, ECT, or TMS
18. are unable to follow the study procedures (e.g., not able to travel to the heated or non-heated yoga studios)