Hyperbaric Oxygen Treatment (HBOT) During Methadone Tapering

The aims of this study are to 1) explore the efficacy of hyperbaric oxygen therapy (HBOT) compared to sham treatment in relieving signs and symptoms (both physical and psychological) of opioid withdrawal in human subjects associated with methadone dose reductions; and 2): explore whether HBOT can increase the odds of successful methadone dose reduction in patients who are interested in tapering their opioid dose. The investigators aim to explore, through qualitative methods, individual\'s experiences with treatment for opioid use disorder (OUD).