Hyperbaric Oxygen Therapy for Depression: What the Research Shows (Investigational)

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Important: Hyperbaric oxygen therapy is not FDA-approved for depression, and it is not a UHMS-listed indication. This is an investigational use. The evidence is preliminary and indirect. Insurance will not cover HBOT for this condition. All costs are out-of-pocket. Nothing on this page is a reason to stop or delay established depression care.

Search interest in HBOT for depression has grown, much of it spilling over from the longevity and brain-injury communities that already use hyperbaric chambers. The honest starting point is that no one has run a trial of HBOT on people whose main diagnosis is depression. What exists is a handful of studies built for other conditions that happened to also measure depressive symptoms along the way. Those numbers are interesting. They are not the same thing as evidence that HBOT treats depression, and the difference matters before anyone spends thousands of dollars on it.

Why People Are Asking About It

Depression is common and often stubborn. First-line treatment, meaning therapy and antidepressant medication, helps a large share of people, but a meaningful group does not respond well to it. Treatment-resistant depression is a real clinical problem, and people living with it understandably look for options beyond the standard menu. That search is where a lot of the HBOT interest comes from.

The biological rationale offered for HBOT is the same one used for brain injury and PTSD. Hyperbaric oxygen increases the amount of dissolved oxygen reaching tissue, and researchers studying it for neurological conditions point to effects on cerebral blood flow and inflammation. Depression involves changes in brain function too, so the leap to depression is easy to make on paper. A plausible mechanism is the reason to study something. It is not a result. A mechanism that shows up in a brain-injury study does not automatically carry over to a different diagnosis with a different biology.

What the Evidence Actually Is

There is no trial of HBOT for primary depression. The depression-related findings that get cited come from trials run for other conditions, where depression scores were collected as a secondary measure.

The most relevant is Doenyas-Barak et al. (2022), a prospective randomized controlled trial published in PLoS One. The study enrolled 35 veterans with treatment-resistant PTSD and compared HBOT against a control arm. Alongside its PTSD outcomes, it tracked depression using the Beck Depression Inventory, and it reported a statistically significant improvement in those depression scores in the HBOT group (PMID: 35192645). That is a depression signal, but it came from a PTSD population, not from people whose primary problem was depression, and the trial was not designed to answer the depression question.

The other often-cited source is Curtis et al. (2021), a small randomized controlled trial of HBOT for fibromyalgia published in Pain Medicine. With 18 patients and a delayed-treatment comparison group, it reported reduced symptoms of anxiety and depression that held at a three-month follow-up (PMID: 33594439). Again, depression was a secondary outcome inside a study about a pain condition, and the sample was very small.

So the picture is narrow and indirect. Two small controlled trials, neither about depression, each reported improved depression scores as a side finding. That is preliminary and hypothesis-generating at best. It is not evidence that HBOT is an effective treatment for clinical depression, and it does not support the confident claims that some clinics attach to it. The Undersea and Hyperbaric Medical Society does not list depression among its accepted indications, and the FDA has not cleared HBOT for it.

What Established Depression Care Looks Like

For context, depression has well-studied treatments with far stronger evidence behind them. Psychotherapy, particularly cognitive behavioral therapy, and antidepressant medications are first-line and are supported by large bodies of controlled-trial data. For treatment-resistant cases, there are recognized next steps your care team can discuss, including medication changes, combination approaches, and procedures used in specialist settings. These are decisions for a licensed clinician who knows your history.

None of that is medical advice for your situation. The point is that anyone weighing HBOT for depression is weighing it against treatments with decades of evidence, and that comparison belongs in the conversation with a doctor. HBOT does not have that track record for this use, and there is no basis for treating it as a substitute for established care.

Cost and the Marketing Around It

Because depression is not an FDA-approved or UHMS-listed indication, no insurer will cover HBOT for it. The cost falls entirely on the patient. At roughly $250-450 per session, and with the protocols used in the PTSD and fibromyalgia research running to dozens of sessions, an out-of-pocket course can reach well into five figures. Rates change and vary by facility, so confirm any figure with the clinic’s billing team before committing.

This is a heavily marketed space, and the secondary depression findings from those few trials sometimes get presented as if HBOT were a depression treatment. It has not been tested as one. Be skeptical of any clinic that cites the PTSD or fibromyalgia numbers without saying that depression was only a side outcome, that quotes improvement percentages without mentioning the small sample sizes, or that implies results are typical or assured. The same caution that applies to any off-label HBOT use worth weighing carefully applies here, with extra weight because depression can be dangerous if it goes undertreated. If a provider is making confident claims about treating depression, the evidence does not back that confidence.

A Word on Safety and Getting Help

Depression is a serious medical condition, and untreated depression carries real risk. If your mood is getting worse, if you are having thoughts of harming yourself, or if you are in crisis, do not wait on an unproven therapy. Call or text 988 to reach the 988 Suicide and Crisis Lifeline, free and confidential, 24/7. For treatment referrals and information about mental health and substance use services, the Substance Abuse and Mental Health Services Administration runs a National Helpline, reachable through samhsa.gov. These are not treatments and not endorsements of any therapy. They are how you reach trained help quickly.

Frequently Asked Questions

Is HBOT a proven treatment for depression? No. No published trial has tested it on people whose main diagnosis is depression. The available depression data are secondary findings from small trials run for PTSD and fibromyalgia. That is preliminary, indirect research, not proof. HBOT has no FDA approval, UHMS listing, or insurance coverage for this use.

What do the studies actually show? Doenyas-Barak et al. (2022) reported improved Beck Depression Inventory scores in veterans with treatment-resistant PTSD (PMID: 35192645). Curtis et al. (2021) reported reduced depression symptoms in a small fibromyalgia trial (PMID: 33594439). In both, depression was a secondary outcome inside a study about a different condition.

Will insurance pay for HBOT for depression? No. Depression is not an FDA-approved HBOT indication, so insurance will not cover it. Expect to pay out-of-pocket, roughly $250-450 per session, across a multi-week protocol.

Should I stop my antidepressant or therapy to try HBOT? No. There is no evidence to support that, and stopping established treatment can be dangerous. Any change to your depression care belongs with your prescriber and care team. If you are in crisis, call or text 988.

References

Doenyas-Barak, K. et al. (2022). Hyperbaric oxygen therapy improves symptoms, brain’s microstructure and functionality in veterans with treatment resistant post-traumatic stress disorder: a prospective, randomized, controlled trial. PLoS One. PMID: 35192645. https://pubmed.ncbi.nlm.nih.gov/35192645/

Curtis, K. et al. (2021). Evaluation of a Hyperbaric Oxygen Therapy Intervention in Individuals with Fibromyalgia. Pain Medicine. PMID: 33594439. https://pubmed.ncbi.nlm.nih.gov/33594439/

The Undersea and Hyperbaric Medical Society (UHMS) lists the accepted indications for hyperbaric oxygen therapy. Depression is not among them. https://www.uhms.org/

988 Suicide and Crisis Lifeline. Call or text 988, available 24/7. https://988lifeline.org/

Browse all conditions on the conditions hub. For related investigational uses where depressive symptoms were measured, see HBOT for PTSD, HBOT for traumatic brain injury and concussion, and HBOT for fibromyalgia.

Medical Disclaimer: This page is for informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Hyperbaric oxygen therapy for depression is investigational and not FDA-approved. Depression is a serious medical condition. Always consult a qualified healthcare provider before making any treatment decisions, and never stop established care on your own. This site does not establish a doctor-patient relationship.