The only possibility of each individual consists of the removal of every darkening obstacle between one's perception and one's consciousness. So this is a matter of developing self-awareness. It is the most obvious conclusion that the material condition of the human body would be the cause of an imperfect psychical functioning. If one suffers from a severe illness the psyche easily can be disturbed, but this isn't inevitable. Actually it regularly proves to be a matter of character whether or not such an illness ruins someone's psychical condition.
Many serious patients show an admirable cheerfulness and human warmth.
So it isn't necessary that one's physical condition is indicative for an eventual psychical disturbance. Mostly someone is able to take no notice of her or his physical condition, actually by the strength of mind. But absolutely disturbing are the cultural and intellectual views which people have about themselves, both concerning their physical as their mental existence. It is absolutely essential how they think about right and wrong and how they are indoctrinated by the morals of the society in which they have to live. Nearly in every civilization a lot of limitations and prohibitions form an insurmountable obstacle for the psyche to manifest herself freely.