In Japan, hikikomori (Japanese: ひきこもり or 引きこもり, lit. 'pulling inward, being confined', i.e., 'acute social withdrawal'; colloquially/adaptive translation: shut-in) are reclusive adolescents or adults who withdraw from society and seek extreme degrees of isolation and confinement. Hikikomori refers to both the phenomenon in general and the recluses themselves. Hikikomori have been described as loners or 'modern-day hermits'. Estimates suggest that half a million Japanese youths have become social recluses, as well as more than half a million middle-aged individuals. The Japanese Ministry of Health, Labour, and Welfare defines hikikomori as a condition in which the affected individuals refuse to leave their parents' house, do not work or go to school and isolate themselves away from society and family in a single room for a period exceeding six months. The psychiatrist Tamaki Saitō defines hikikomori as 'a state that has become a problem by the late twenties, that involves cooping oneself up in one's own home and not participating in society for six months or longer, but that does not seem to have another psychological problem as its principal source'. More recently, researchers have developed more specific criteria to more accurately identify hikikomori. During a diagnostic interview, trained clinicians evaluate for: The psychiatrist Alan Teo first characterized hikikomori in Japan as modern-day hermits, while the literary and communication scholar Flavio Rizzo similarly described hikikomori as 'post-modern hermits' whose solitude stems from ancestral desires for withdrawal. While the degree of the phenomenon varies on an individual basis, in the most extreme cases, some people remain in isolation for years or even decades. Often hikikomori start out as school refusers, or futōkō (不登校) in Japanese (an older term is tōkōkyohi (登校拒否)). While many people feel the pressures of the outside world, hikikomori react by complete social withdrawal. In some more extreme cases, they isolate themselves in their bedrooms for months or years at a time. They usually have few or no friends. In interviews with current or recovering hikikomori, media reports and documentaries have captured the strong levels of psychological distress and angst felt by these individuals. While hikikomori favour indoor activities, some venture outdoors occasionally. The withdrawal from society usually starts gradually. Affected people may appear unhappy, lose their friends, become insecure and shy, and talk less. According to Japanese government figures released in 2010, there are 700,000 individuals living as hikikomori within Japan, with an average age of 31. Still, the numbers vary widely among experts. These include the hikikomori who are now in their 40s and have spent 20 years in isolation. This group is generally referred to as the 'first-generation hikikomori.” There is concern about their reintegration into society in what is known as 'the 2030 Problem,” when they are in their 60s and their parents begin to die. Additionally, the government estimates that 1.55 million people are on the verge of becoming hikikomori. Tamaki Saitō, who first coined the phrase, originally estimated that there may be over one million hikikomori in Japan, although this was not based on national survey data. Nonetheless, considering that hikikomori adolescents are hidden away and their parents are often reluctant to talk about the problem, it is extremely difficult to gauge the number accurately.