Children and adolescents who moved longer distances or more frequently before 16 years of age were significantly more likely to develop psychosis in early adulthood than were those with less residential mobility, according to data from about 1.4 million children and adolescents in Sweden.
Data from previous studies have supported a link between childhood residential mobility and subsequent nonaffective psychoses, but no research has addressed the effects in later adolescence and young adulthood until now, wrote Ceri Price of Cardiff (Wales) University and colleagues.
In a study published in JAMA Psychiatry, the researchers reviewed data from a population-based cohort of individuals who were born in Sweden between Jan. 1, 1982, and Dec. 31, 1995, and lived in Sweden at age 16 years. The participants were followed from their 16th birthdays until a diagnosis of a nonaffective psychotic disorder, death, censorship because of emigration, or Dec. 31, 2011 – whichever came first.
Overall, the most sensitive range for an association between moving and psychosis was ages 16-19 years; the adjusted hazard ratio for a nonaffective psychotic disorder was 1.99 for participants who moved each year between ages 16 and 19 years, compared with those who never moved. In addition, moving greater distances before 16 years of age was independently associated with an increased risk of nonaffective psychosis (HR, 1.11) and the data suggested a nonlinear threshold effect when the distance moved exceeded 30 km.
A total of 4,537 individuals had a nonaffective psychotic disorder at a median 21 years of age, and a dose-response relationship emerged between more frequent moves and increased risk of nonaffective psychosis after controlling for confounding variables.
By contrast, a single move in young adulthood was not associated with increased psychosis risk, but moving at least four times during young adulthood was associated with an increased risk (adjusted HR, 1.82).
The study findings were strengthened by the longitudinal design and large population, but they were limited by several factors, including an absence of data on other adverse childhood experiences, such as family discord; peer relationships, such as friendships and bullying; and information on school changes and the disruption of peer relationships, the researchers wrote.
However, the results support the theory that psychosis risk can be affected by the disruption of social networks, peer support, and identity formation that occurs when children and adolescents move, and these results have potential implications for child health services and social policy, they noted.
“It is important that health, social, and educational practitioners ensure that children and adolescents who are newly resident to their neighborhoods receive adequate support to minimize the risks of adverse outcomes during adulthood, and every effort should be made to ensure the effective transfer of care for highly mobile children who are already in contact with health and social services,” they said.
The researchers had no financial conflicts to disclose. The study was supported in part by the Wellcome Trust and the Royal Society.
SOURCE: Price C et al. JAMA Psychiatry. 2018 Aug 22. doi: 10.1001/jamapsychiatry.2018.2233.