Higher genetic risk for schizophrenia is associated with living in more densely populated areas

Social stress in urban life has been proposed as an environmental risk factor associated with the increased prevalence of schizophrenia in urban compared to rural areas. However, the potential genetic contributions to this... [ view full abstract ]

Social stress in urban life has been proposed as an environmental risk factor associated with the increased prevalence of schizophrenia in urban compared to rural areas. However, the potential genetic contributions to this relationship have been largely ignored.

We used data of genotyped adults from four independent non clinical cohorts. Analyses performed in the discovery cohort (QIMR, Australia, N=15,544) were replicated in participants from the UKB (United Kingdom, N = 456,426), the NTR (The Netherlands, N = 16,434) and QSKIN (Australia, N = 15,726).

We found higher genetic loading for schizophrenia inparticipants living in more densely populated areas. Mendelian Randomizationsuggested that high schizophrenia genetic risk is a causal factor in choosingto live in denser areas; these results were only significant in the UKB, ourlargest cohort.

Our study investigates the association between genetic risk for schizophrenia and characteristics of where people live using data from 504,130 participants from three different countries. Our results support the hypothesis of selective migration to more urban environments by people at higher genetic risk for schizophrenia and suggest a need to refine the social stress model for schizophrenia by including genetic influences on where people choose to live.