Longitudinal effects of neighbourhoods' material and social deprivation on psychological distress of adults in Canada.

Objectives: This nationwide longitudinal study investigates the impact of neighbourhood deprivation on psychological well-being of Canadian adults.

Methods: Utilizing data from the Longitudinal and International Study of Adults (LISA) spanning 2016, 2018, and 2020, we included individuals aged 15 and above across Canada. The 2016 and 2020 samples comprised approximately 17,700 and 12,700 respondents, respectively. LISA data were paired to Neighbourhood Material and Social Deprivation data derived from Canada's 2016 Census. Psychological distress was assessed using the Kessler Scale (K-10), both dimensionally (score) and categorically (above the cut-point prevalence). Multi-level mixed-effects regressions were conducted, adjusting for individual-level variables.

Results: At baseline, participants' mean age was 47.7 years (50.6% female), and higher social and material deprivation were associated with greater psychological distress. Longitudinally, psychological distress showed distinct temporal patterns based on the type of deprivation. Adjusted models revealed that residing in the most socially deprived neighbourhoods was linked to a greater increase in psychological distress scores over time as compared with the least socially deprived areas. Conversely, the highest degree of material deprivation showed a negative association with increasing distress, contrasting with the lowest material deprivation. A similar trend emerged regarding the prevalence of high psychological distress: in the most socially deprived neighbourhoods, there was an elevated prevalence over time, whereas the highest material deprivation was negatively associated with increasing prevalence.

Conclusion: This study supports the link between mental health and neighbourhood social deprivation, but differs from previous research regarding material deprivation. While material support remains crucial for disadvantaged communities, public health interventions should also address social deprivation.