If we look at the breath from a spiritual point of view it is possible that people who are anxious may have a tenuous connection with their deeper selves. The beauty of the breath is that we can gain control over it even though it is an autonomic response. With that knowledge and a willingness to give attention to the breath people can begin to gain an authentic role in their well being on a physical and spiritual level.
Attention to the breath also increases a mindfulness to the present moment, which helps undo old patterns which may have lead to anxiety. Simply by bringing the attention to the breath which can only happen in the “now” engenders a sense of calm, relaxation and peace.