physiological effects of isolation
One of the negative effects of isolation is the removal of familiar objects and routines, which may evoke fear, anxiety, depression, and rapid mood changes (Kennedy and Hamilton, 1997; Knowles, 1993). The stigma of isolation.
Research in rhesus monkeys and humans has shown that social isolation during childhood has an array of nasty and lifelong effects, from cognitive and social problems in neglected children to working memory troubles in isolated monkeys.