Study finds two-way causal links between poverty, mental illnesses

Living in poverty could be causing mental illnesses and vice-versa, according to a study. While previous studies have shown a strong correlation between poverty and mental illness, researchers said that they have not been able to discern the cause-and-effect relationship between the two.

While certain mental conditions are known to impact financial stability, the authors found that poverty “can lead to mental health problems”. They analysed data from the UK Biobank and the international Psychiatric Genomic Consortium.

“We discovered that schizophrenia and attention deficit hyperactivity disorder (ADHD) causally contribute to poverty. Conversely, poverty contributes to major depressive disorder and schizophrenia,” said
Marco Boks, a psychiatrist at Amsterdam University Medical Center in The Netherlands.

People with ADHD have short attention spans, along with restlessness and impulsivity, while those with schizophrenia harbour a distorted perception of reality, affecting how they think, feel and behave.
For the study, published in the journal Nature Human Behaviour, the researchers determined a measure of poverty, using household income, occupational income and social deprivation.

They then used the genetic information of the participants to distinguish the effects of poverty on mental health and vice-versa. They used the Mendelian randomisation method, which helps understand how a
certain exposure (such as poverty) caused a certain outcome (developing a mental illness).

“We were able to capture aspects of poverty shared between the individual, the household, and the area in which one lives. This enabled us to better identify the causal effects of poverty on mental
illness,” said author David Hill, a statistical geneticist at the University of Edinburgh, UK.

The researchers said using genetic data, they were able to identify poverty as something that can be targeted in order to improve mental health. They said that by recognising the two-way influence between poverty and mental health, policymakers can develop more effective interventions aimed at breaking the cycle.

“The research provides robust evidence for the need to also look at social factors such as poverty, when you delve into the development of mental illness,” said Boks.