What William Trubridge is describing in the article is something called the 'death wish', which is a well known phenomenon that I first experienced in 2001.
The vast majority of freedivers have not experienced it, and someone who hasn't experienced it will read the article and think it is exaggeration or sensational.
Your unconscious mind seems to set a depth limit for you without your knowledge. If you try a very deep dive on a line, with safety in place, you can gradually get deeper and deeper. As your skill improves, and as your tolerance for pain & discomfort on the ascent improve, you get deeper and deeper.
Eventually, you seem to hit a wall, a depth beyond which your unconscious mind will not allow you to pass. You know that each time you hit that wall, the ascent is unbearably painful, and you barely make it back to the surface. To go beyond it is asking for it. In order to go beyond it, you need the 'death wish,' or the acceptance that going beyond that magic depth could put your safety in serious peril. Generally, the diver needs some sort of tremendous motivation to be able to break over the barrier. And it never changes, each time the diver goes beyond that depth, the death wish is required.
I know of several divers who never were able to conjure the death wish, and thus were never able to go beyond a certain depth. Women in particular seem to have 'more common sense' and thus are less likely to acquire the death wish.
I myself have only conjured the death wish on perhaps six or seven occasions.
