Meditation and Mental Disease

What is the position of knowledge from meditation?
The basic tool of meditation is to focus. Anything, as you are interested and focus on continuously, you will discover something about it. The common example is scientific research. Meditation uses the same basic tool, but the logic process may not as rigorous as science.
What is the difference between the state of meditation and mental disease?
In state of meditation, the inner sensors in brain are awake and can speak and hear, sometimes very meaningfully, and sometimes very disturbingly. For my self was a physician, I reason the mechanism of the phenomena is very similar to some mental disease.