The Mind Parasites by Colin Wilson

Wilson has blended H.P. Lovecraft's dark vision with his own revolutionary philosophy and unique narrative powers to produce a stunning, high-tension story of vaulting imagination. A professor makes a horrifying discovery while excavating a sinister archaeological site. For over 200 years, mind parasites have been lurking in the deepest layers of human consciousness, feeding on human life force and steadily gaining a foothold on the planet. Now they threaten humanity's extinction. They can be fought with one weapon only: the mind, pushed to--and beyond--its limits. Pushed so far that humans can read each other's thoughts, that the moon can be shifted from its orbit by thought alone. Pushed so that man can at last join battle with the loathsome parasites on equal terms.