There are some Tibetan monks who meditate on dissolving chunks of their being slowly as they meditate so that all is left is nothing of them or their consciousness. They merge into nothingness. Other practices focus on merging into the global consciousness. Maybe the article is about someone who wandered off into parts he didn't have any business wandering in?
Note that my "reality" here is lack of circumstantial evidence for the harmful effects of meditation, which would just help identify there was a problem to begin with. In theory, this could be put to the scientific method to prove or disprove, given you could measure someone's mental state using something other than "he seems unstable today", which you can't, without speaking for someone else.
While it might be unsurprising that meditation did not provide direct benefits to mind or body, it also failed to insulate or deflect these people away from new misery.
It's interesting to learn that the people described in the article had uncovered unsettling realities about themselves while meditating.
Knowing what I know about many people, uncompromising introspection is not something everyone would be comfortable with. Some people are jerks. Some people have their head in the clouds.
Grinding one's life to a halt, and taking a hard look in the mirror, is bound to derail an unrealistic world view now and again. But if, on the other side of an unceremonious introduction to cold reality, awaits absolutely no way to fix profound disappointment...
What then?