IMPORTANCE Residential mobility (changing residence) during childhood and early
adolescence is a possible risk factor for several adverse health outcomes, including psychotic
disorders. However, it is unclear whether sensitive periods to residential mobility exist over
the life course, including in adulthood, or if greater moving distances, which might disrupt
social networks, are associated with a greater psychosis risk.
OBJECTIVE To examine the association between residential mobility over the life course and
the risk of nonaffective psychosis.
DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study included all people born
in Sweden between January 1, 1982, and December 31, 1995, who were alive and resided in
Sweden on their 16th birthday who were followed up until up to age 29 years (ending
December 2011). Participants were followed until receiving a first diagnosis of an International
Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10)
nonaffective psychotic disorder (F20-29), emigration, death, or the end of 2011, whichever
was sooner. National register linkage provided exposure, outcome, and covariate data
(complete data were available for 1 440 383 participants [97.8%]).
EXPOSURES The exposures to distance moved and the number of residential moves were
examined for participants at the following periods over the life course: 0 to 6 years, 7 to 15
years, 16 to 19 years, and 20 years and older.
RESULTS This study included 1 440 383 participants, of whom 4537 (0.31%) had nonaffective
psychotic disorder (median age, 20.9 [interquartile range, 19.0-23.3]). More frequent moves
during childhood and adolescence were associated with an increased risk of nonaffective
psychosis that showed dose-response associations independent of covariates. The most
sensitive period of risk occurred during late adolescence; those who moved during each year
between age 16 to 19 years had an increased adjusted hazard ratio (HR) of 1.99 (95% CI,
1.30-3.05) compared with those who never moved. One move during adulthood was not
associated with psychosis risk (adjusted HR, 1.04; 95% CI, 0.94-1.14), but moving 4 or more
times during adulthood was associated with increased risk (adjusted hazard ratio, 1.82; 95%
CI, 1.51-2.23). Independently, moving greater distances before age 16 years was associated
with an increased risk (adjusted HR, 1.11; 95% CI, 1.05-1.19), with evidence of a nonlinear
threshold effect for moves longer than 30 km. The distance moved after age 20 years was
associated with a decreased risk (adjusted HR, 0.67; 95% CI, 0.63-0.71).
CONCLUSIONS AND RELEVANCE Children and adolescents with less disruption in their
residential environments are less likely to experience psychotic disorders in early adulthood.
Moves that may necessitate changes in school and social networks were most strongly
associated with future risk