I dont need to. The relaxation inherent in deep breathing has nothing to do with increased oxygen levels, which if anything, would make you euphoric and impar judgement further.

Regulated breathing tells the autonomic emergency systems that it is ok to shutdown- it is the domino you push that sends all other fight or flight responses toppling.

Like I said, you are free to believe what you wish.
Don't let the door hit ya' where the good lord split ya'