The effect on the mind comes because the asanas move prana in the body. When prana flows freely, you have everything you need to feel well. Your mind can stop chasing and racing and rests comfortably in the present moment.
Paschimottanasana, or West side facing up pose, is a good practice for moving prana in your body so that your mind can find peace wherever it is. But the key to the flow of prana is in how you practice.