Therese J. Borchard writes this article acknowledging the importance of deep breathing in her personal recovery from problems such as anxiety and depression. She writes that shallow breathing contributes to feelings of panic and that she has personally been reduced to breathing out of a paper bag to maintain physical control of her breathing on more than one occasion. Deep breathing is so helpful in times of anxiety and stress because it stimulates the parasympathetic nervous system (PNS), which is responsible for our body activity when we are rest. It works opposite of the sympathetic nervous system which controls fight-or-flight responses.
Read the full article here: 3 Deep Breathing Exercises to Reduce Anxiety