The number of asylum seekers, refugees and people driven out of their homes but still living in their own country rose to 20.8 million at the beginning of 2006. In 2005, in the U.K., 29,210 people left detention of whom 59% were deported. Asylum seekers have often experienced traumatic events in their country of origin and while they are detained they can suffer from the extra stress caused by loss of liberty, not knowing whether they will be sent back to their country of origin, social isolation and abuse from staff. A team of researchers from the U.K. reviewed ten studies into the mental health of people detained as asylum seekers. They found that anxiety, depression, post-traumatic stress disorder (PTSD), self-harm and suicidal thoughts were commonly reported. The longer people had been in detention the more likely they were to suffer from a mental-health problem. There was some evidence that people's mental health improved after they were released but there was a long-lasting negative affect from detention.
Robjant, Katy, Hassan, Rita and Katona, Cornelius - Mental health implications of detaining asylum seekers: systematic review British Journal of Psychiatry April 2009, 194(4), 306-312