Researchers recently conducted a review on the impact of income inequality on mental health. They report that income inequality has a small but significant effect on the development of mental disorders, particularly depression.
Mental illness is a growing problem in society, with evidence suggesting a prevalence rate of about 18% in adults and just over 13% in young people. With so many affected individuals, a lot of research been aimed at discovering not only the biological factors that facilitate the development of these disorders, but also the social ones. In particular, there is a lot of concern over the role that income inequality has on mental illness. It has been hypothesized that being economically disadvantaged causes additional life stress that can be conducive to the development of certain mental diseases. Others have suggested that income inequality results in status competition between individuals, affecting peoples self esteem, which can further affect mental health. Past studies on the effect of economic status on mental health have demonstrated varying results. The authors of a recent study published in The Lancet Psychiatry conducted a meta-analysis in the hopes of finding some conclusive answers about the impact of income inequality on mental health.
The researchers searched 6 databases for studies using keywords related to income, mental health and resilience. Relevant studies published before July 2016 were included, regardless of the age of the participants. Selected articles were tested for quality based on parameters such as study design and the presence of selection bias, and data from 9 articles underwent meta-analysis. Of these studies, only 1 demonstrated a definitive association between income inequality and mental illness. The remaining 8 found either conflicting results or no association at all. However, after collectively analyzing the results from all 9 papers using the pooled Cohen’s d effect size method, researchers found a small but significant association between income inequality and mental illness in general, as well as a slightly larger association between income inequality and depression. These results clearly indicate that differences in economic status contribute to the presence of mental illness in society.
These results shed some light on the role that class and economic status play in the development of mental disorders, particularly depression. This is important, as depression has become one of the biggest causes of disability. However, these results should be interpreted with caution, as the meta-analysis only looked at 9 past studies, which is not a large enough sample to draw conclusions that are generalizable. Nevertheless, these results do help to create a better understanding of the role that social factors play in mental illness.
Written By: Sonia Parmar, BSc