Hyperbaric oxygen therapy as a potential treatment for MDD: a narrative review

This narrative review explores the therapeutic potential of hyperbaric oxygen therapy (HBO₂) in treating major depressive disorder (MDD). We highlight the common pathophysiological hypotheses for MDD, the strengths and limitations of current MDD treatments, and the potential for HBO₂ to be a novel MDD therapeutic through anti-inflammatory and neuroprotective mechanisms. The current review discusses the monoamine, neuronal atrophy, and inflammation hypotheses of MDD pathophysiology origin, as well as how present MDD therapeutics target these MDD pathophysiological traits. While there are a multitude of existing treatments for MDD, including those pharmacological, psychotherapeutic, and neuromoduatory in nature, many treatments possess limitations. The management of difficult-to-treat depression is particularly challenging, highlighting the need for innovative, effective treatments to be developed. HBO₂ is a potential novel therapy for MDD, exerting antidepressant effects through its ability to promote neurogenesis and anti-inflammatory processes in the central nervous system. Moreover, HBO₂ has been indirectly correlated with an improvement in depressive symptoms in studies done in the context of treatment for post-traumatic stress disorder (PTSD), traumatic brain injury (TBI), post-stroke recovery, and post-coronavirus disease condition (post-COVID-19). However, there is currently a dearth of direct evidence supporting the indication of HBO₂ for MDD, and clinical trials that investigate HBO₂ as a primary treatment for MDD are needed. The current review provides a rationale for further exploration of the potential of HBO₂ as a novel therapy for MDD.