Sleep is a very important part of our lives and is in our very nature. If asked for advice to stay mentally healthy, one must always consider if you are getting enough sleep. And not just enough sleep; good, restful sleep. Sleep can be the very root of disorders such as depression, bi-polar disease. Even anxiety disorders have been linked to to not getting restful sleep. Always take into consideration if not enough restful sleep could be the cause of such disorders, and it is not a bad idea to see a doctor about such problems.