Examining relationships between the Danish Composite Deprivation Index and risk of developing schizophrenia: A national multilevel analysis

TY - JOUR

T1 - Examining relationships between the Danish Composite Deprivation Index and risk of developing schizophrenia

T2 - A national multilevel analysis

AU - Horsdal, Henriette T

AU - Jensen, Anja S

AU - Antonsen, Sussie

AU - Pedersen, Marianne G

AU - Trabjerg, Betina B

AU - Thompson, Wesley K

AU - Fan, Chun C

AU - Sabel, Clive E

AU - Agerbo, Esben

AU - Pedersen, Carsten B

AU - Webb, Roger T

N1 - Copyright © 2025 The Author(s). Published by Elsevier B.V. All rights reserved.

PY - 2025/11

Y1 - 2025/11

N2 - BACKGROUND: Few population-based multilevel analyses examining individual- and neighborhood-level risk factors for schizophrenia have been conducted.METHODS: A study cohort of all persons born in Denmark from 1990 to 1999 was followed for diagnosis with schizophrenia. Follow-up was initiated at 10th birthday and terminated at death, emigration, incident diagnosis, or 31st December 2018, whichever came first. A Danish Composite Deprivation Index was derived using 10-year weighted average neighborhood-level indicators in 1990-1999 categorized into five domains: Income; Employment; Education, Skills & Training; Health & Disability; and Crime. By fitting multilevel log-linear Poisson regression models, neighborhood-level deprivation indicators were examined with and without adjustment for individual-level covariates.RESULTS: Four neighborhood-level deprivation domains, Employment, Education, Skills & Training, Health & Disability, and Crime, as well as the Danish Composite Deprivation Index (adjusted IRR 1.14; 95 % credibility interval 1.10-1.17), were associated with elevated risk independent of individual-level deprivation measures. The specific neighborhood-level indicators linked with the highest adjusted elevations in risk were: Proportion of inhabitants aged 18-22 years who did not complete primary school before age 18 (adjusted IRR 1.23; 1.20-1.27); Proportion of inhabitants convicted for any violent crime (adjusted IRR 1.19; 1.16-1.23); and Proportion of inhabitants convicted for any crime resulting in a custodial sentence (adjusted IRR 1.15; 1.12-1.18).CONCLUSION: This novel population-based multilevel analysis has evidenced the independent associations of neighborhood-level deprivation indicators on schizophrenia risk elevation. Replication is needed in other populations to inform the refinement of preventive strategies.

AB - BACKGROUND: Few population-based multilevel analyses examining individual- and neighborhood-level risk factors for schizophrenia have been conducted.METHODS: A study cohort of all persons born in Denmark from 1990 to 1999 was followed for diagnosis with schizophrenia. Follow-up was initiated at 10th birthday and terminated at death, emigration, incident diagnosis, or 31st December 2018, whichever came first. A Danish Composite Deprivation Index was derived using 10-year weighted average neighborhood-level indicators in 1990-1999 categorized into five domains: Income; Employment; Education, Skills & Training; Health & Disability; and Crime. By fitting multilevel log-linear Poisson regression models, neighborhood-level deprivation indicators were examined with and without adjustment for individual-level covariates.RESULTS: Four neighborhood-level deprivation domains, Employment, Education, Skills & Training, Health & Disability, and Crime, as well as the Danish Composite Deprivation Index (adjusted IRR 1.14; 95 % credibility interval 1.10-1.17), were associated with elevated risk independent of individual-level deprivation measures. The specific neighborhood-level indicators linked with the highest adjusted elevations in risk were: Proportion of inhabitants aged 18-22 years who did not complete primary school before age 18 (adjusted IRR 1.23; 1.20-1.27); Proportion of inhabitants convicted for any violent crime (adjusted IRR 1.19; 1.16-1.23); and Proportion of inhabitants convicted for any crime resulting in a custodial sentence (adjusted IRR 1.15; 1.12-1.18).CONCLUSION: This novel population-based multilevel analysis has evidenced the independent associations of neighborhood-level deprivation indicators on schizophrenia risk elevation. Replication is needed in other populations to inform the refinement of preventive strategies.

KW - Deprivation

KW - Epidemiology

KW - Multilevel analysis

KW - Risk factors

KW - Schizophrenia

UR - https://www.scopus.com/pages/publications/105014992635

U2 - 10.1016/j.schres.2025.09.001

DO - 10.1016/j.schres.2025.09.001

M3 - Journal article

C2 - 40915237

SN - 0920-9964

VL - 285

SP - 52

EP - 59

JO - Schizophrenia Research

JF - Schizophrenia Research

ER -