hikikomori - The Japanese have a word for it for their own reasons.  In America it is just called depression.

People have a natural tendency to withdraw for self-protection.  If you can keep yourself entertained dispensing with toxic people is a good idea.  Withdrawing regarding specific situations and people is good, but withdrawing as a lifestyle is mentally ill.  In America it is best to keep an opinion like mine to yourself.  Labeling any lifestyle as mentally ill is an attack on FREEDOM here.  Japan can admit that they have a social problem because Japanese are comfortable with a need to conform.  In America we have the same thing going on, but there is more denial so this depression is not seen for what it is.  In America conformity attacks self-expression and is not tolerated as a virtue.

Parents who set no limits, and who expect their special flowers to bloom by the natural process of life unfolding without providing any direction are a huge problem.  Some people have a propensity to figure out how their own life works.  These people can direct their own path.  Other people are without any clue at all without any ability to sail their own ship.  When permissive parents parent the clueless the environment becomes toxic in the family and beyond.

Economics provided the environment where this sort of depression is became possible.  Material conditions to support this sickness were once available only to the rich.  In the seventies middle class American men knew they were expected to get a job and move out of the parents house at age 18 because, parents had paid their bills long enough.  That expectation vanished when decent jobs became scarce and the American economy became wonky.  Necessity forced families together at the same time avoidance of shitty jobs became a virtue.  With basic needs met self-expression became more important than being part of the social fabric.

The definition of shitty is rarely objective.