Trajectories of housing affordability and mental health problems: a population-based cohort study.

Purpose: With housing costs increasing faster than incomes and a limited supply of social housing options, many households face unaffordable housing. Housing affordability problems may negatively impact mental health; however, longitudinal evidence is limited. This study investigates the association between trajectories of housing affordability problems and mental health.

Methods: We used data from 30,025 households from Understanding Society, a longitudinal household survey from the UK. Participants spending 30% or more of household income on housing were categorised as facing housing affordability problems. We estimated group-based trajectories of housing affordability problems from 9 waves of data (2009-2019). We used linear regression to calculate the association between the trajectories and mental health problems, as measured by General Health Questionnaire (GHQ) score in Wave 10 (2018-2020).

Results: We found six distinct trajectories of housing affordability problems. Those in the 'stable low' group had a consistently low probability of affordability problems, whilst those in 'high falling' group had a sustained high probability in the earlier waves of the study, subsequently decreasing over time. The adjusted analysis showed that trajectory group membership over the first nine waves of data predicted GHQ score in 2018-2020 (Wave 10). Compared to the 'stable low' group, those in the 'high falling' group had a GHQ score that was 1.06 (95% CI 0.53-1.58) points higher.

Conclusion: This study provides evidence that sustained exposure to housing affordability problems is associated with long-term worse mental health, even in the absence of more recent problems.