How, when, and why is social class linked to mental health and wellbeing? A systematic meta-review

Meta-reviews synthesising research on social class and mental health and wellbeing are currently limited and focused on specific facets of social class (e.g., social capital) or mental health and wellbeing (e.g., mental health disorders), and none sought to identify mechanisms in this relationship.

The present meta-review sought to (1) assess the overall relationship between social class and mental health and wellbeing, (2) determine the mechanisms that act in this relationship, and (3) evaluate the strength of evidence available.

The protocol was prospectively registered on PROSPERO (CRD42021214731). We systematically searched twelve databases in September 2022 and identified 149 eligible reviews from 38,257 records screened. Quality of evidence was assessed with the JBI levels of evidence and risk of bias with the ROBIS tool.

A large but low-quality evidence base points to class-based inequalities in mental health and wellbeing, with the strongest available evidence linking lower social positions to an increased risk of depression. In terms of different facets of stratification, the best available evidence suggests that deprivation (e.g., poverty), socioeconomic status, income, and subjective social status are consequential for individuals' mental health and wellbeing. However, high-quality evidence for the roles of education, occupation, other economic resources (e.g., wealth), and social capital is currently limited. Most reviews employed individual-level measures (e.g., income), as opposed to interpersonal- (e.g., social capital) or community-level (e.g., neighbourhood deprivation) measures. Considering mechanisms, we found some evidence for mediation via subjective social status, sense of control, and experiences of stress and trauma. There was also some evidence that higher socioeconomic status can provide a buffer for neighbourhood deprivation, lower social capital, and lower subjective social status.

Future research employing experimental or quasi-experimental methods, and systematic reviews with a low risk of bias, are necessary to advance this area of research.