At the base of the mental health is the idea that we have to think of our whole life as one unit of body, mind and spirit.
Whatever we do for the body or mind, must do good to the whole person as one.
If we keep entertaining the thoughts of different diseases, their nature and how dangerously they can ruin our lives, we will invite those symptoms of the disease in our body.
Let us think about health and healthy activities all the time. Our thoughts, words and actions should be in harmony with one another. When we think of doing something good, we should say it at least to ourselves and we should follow it up with action. So never give an opportunity for the mind to develop weeds. Be engaged in some creative activity when not resting. Make meditation a daily practice.
These will help cultivate a healthy mind.