Meditation

Meditation is medication for the mind. Being still and taking time each day helps in centering our minds, giving our brains a rest, and strengthening our minds to aid in the control of our automatic emotional response.

Taking the time to get in between our thoughts helps calm and clear the mind. Along with breath work.
Regular practice helps to keep your mind healthy, and lower blood pressure as well.
I learned when I asked Deepak Chopra what is the difference between prayer and meditation.

Prayer is talking with God and meditation is listening.

Many different ways and types of meditation.
Guided meditation is a great place to start and easier for everyone and anyone to do as you don't have to stress about clearing and it gives you something to concentrate on. 

Meditation is concentration.