I think the message is clear enough for anyone who think 3 dimensionally. Depression, lack of sleep, fear, nightmares, childhood memories, destiny, various area of the mind such as the analytical, the clever, the inner child...
... all parts of the Id.
The clairvoyant, (if such a thing existed) would be a prisoner of their own mind. A prisoner of the past, present, and future. As such the clairvoyant would be unable to slumber, even though they desperately need it, as their fear of the prison of slumber would force them to feel as though they have to take drastic measures to stay awake... like self-mutilation and excrutiating pain.
As aforementioned... the message is plain to see, to those who can see it. :-)
Depression is a heck of a thing. Perhaps one should see a mental health professional if they are seeing and feeling such a way as this.