Increased income over time predicts better self-perceived mental health only at a population level but not for individual changes: An analysis of a longitudinal cohort using cross-lagged models

J Affect Disord. 2021 Sep 1:292:487-495. doi: 10.1016/j.jad.2021.05.118. Epub 2021 Jun 5.

Abstract

Background: The literature identifies a strong relationship between mental health and income, but there is little research that clarifies the directional association between household income and self-perceived mental health (SPMH) overtime either at between-perso+n or within-person levels. This study investigates whether higher income predicts better SPMH overtime and poor SPMH predicts lower income overtime both at between-person or within-person levels.

Methods: Data analyzed was from the Montreal Southwest Social and Psychiatric Epidemiology Catchment Area study (ZEPSOM), a longitudinal community-based cohort. The baseline survey was conducted in 2007/8 with follow-up every two years. We traced a total of 3464 participants over a period of 8 years. To examine the associations between income and SPMH at both between-person or within-person levels, cross-lagged panel models (CLPMs) and random intercept cross-lagged panel models (RI-CLPMs) were used. Gender and age effects were examined using multiple group analyses. Complete case analyses evaluated the findings' robustness.

Results: At between-person levels, higher household income predicted higher SPMH, but not vice versa. These associations were stronger among men and older adults. At within-person levels, higher income did not predict higher SPMH. No significant gender- or age- group differences were observed. Complete case analyses supported the findings.

Limitations: Loss to follow-up may affect the generalizability of the research findings.

Conclusions: This study suggests that higher household income predicts higher SPMH at between-person levels. Policy and programs aiming at promoting mental health should focus on low-income individuals, especially men and older adults.

Keywords: Health selection; Income; Population cohort; Self-perceived mental health; Social causation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cohort Studies
  • Humans
  • Income*
  • Male
  • Mental Health*
  • Surveys and Questionnaires

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