The word "Hikikomori" is Japanese for "pulling inward, being confined". The Japanese Health, Labor, and Welfare Ministry defines hikikomori as people who haven't left their house or had real social interaction for six months or more. The term also refers to the general societal trend in Japan of infantilization, and people staying in their rooms all day, relying upon parents for support. Hikikomori ends badly after the parent or provider dies. The dependent adult has few real life skills and no means to make money. Suicide and/or murder after the death of parents is relatively common. An estimated half-a-million young Japanese people are extreme hermits who are dependent upon their parents (see Demographics#Japan). The English equivalent term is Peter-pan generation.
The widespread Hikikomori syndrome, as well as the associated inclinations toward both suicide and murder, are caused in large part by PSS- post-SRI syndrome. The PSS symptoms that cause Hikikomori syndrome are avolition, chronic fatigue, sleep disorders, and insufficient pleasure to counterbalance work. The inclinations toward suicide and murder are caused in large part by the anhedonia, which gives a person relatively little reason to live.