·  Poverty, Depression and Anxiety: The Role of Debt.
(1 March 2021) 
The recent review by Ridley and colleagues (1) discusses many possible mechanisms linking poverty to depression and anxiety such as employment, income, insurance, environmental factors, poor physical health and exposure to violence. However, their review omits all mention of debt, a key economic variable. 
A meta-analysis (2) found that unsecured debt such as credit card debt was linked to a more than 3-fold increased risk of mental health problems, with an unadjusted odds ratio for depression specifically of 2.77. The impact of debt on mental health holds after controlling for demographic variables, measures of social class and income (3). Debt appears to be more strongly linked to depression and anxiety than income (4) and partially moderates the link between low income and mental disorder (3). There is also a dose-response relationship with more debts increasing the risk of a mental health problem further (5), and subjective stress about debt more strongly predicts depression than actual objective amount of debt (6).
The impact of debt specifically on depression and anxiety has been found in a range of populations such as farmers (7), older adults (8) and new mothers (9). Whilst the majority of these studies are from developed countries, in particular the UK and USA (2), an impact of debt on depression has been shown in developing countries such as Uganda (9), and a number of countries in Asia (10). Whilst most research is cross-sectional and more longitudinal research in this area is needed (2), there is strong evidence for debt as a significant and independent economic variable which links poverty to poor mental health. Further research to understand the mechanisms of this relationship will inform practice and policy which may ultimately reduce the burden of debt on mental health.
Thomas Richardson, Solent NHS Trust and University of Southampton, UK.
Rachel Jenkins, Kings College London, UK.
Nick Maguire, University of Southampton, UK.
Sharon Collard, University of Bristol, UK.
Jamie Evans, University of Bristol, UK.
Chris Fitch, University of Bristol, UK.
Maria Barnes, University of Bristol, UK.
Sally McManus, City, University of London.
Charlotte Franhkam, West London NHS Trust, UK.
References
1. M. W. Ridley, G. Rao, F. Schilbach, V. H. Patel, Poverty, Depression, and Anxiety: Causal Evidence and Mechanisms. Science. 370, eaay0214 (2020).
2. T. Richardson, P. Elliott, R. Roberts, The relationship between personal unsecured debt and mental and physical health: A systematic review and meta-analysis. Clinical psychology review 33, 1148-1162 (2013).
3. R. Jenkins et al., Debt, income and mental disorder in the general population. Psychological Medicine 38, 1485-1493 (2008).
4. P. Drentea, J. R. Reynolds, Neither a Borrower Nor a Lender Be The Relative Importance of Debt and SES for Mental Health Among Older Adults. Journal of Aging and Health 24, 673-695 (2012).
5. H. Meltzer, P. Bebbington, T. Brugha, M. Farrell, R. Jenkins, The relationship between personal debt and specific common mental disorders. Eur J Public Health 23, 108-113 (2013).
6. S. Bridges, R. Disney, Debt and depression. Journal of health economics 29, 388-403 (2010).
7. C. L. Beseler, L. Stallones, A cohort study of pesticide poisoning and depression in Colorado farm residents. Annals of Epidemiology 18, 768-774 (2008).
8. A. Hiilamo, E. Grundy, Household debt and depressive symptoms among older adults in three continental European countries. Ageing & Society 40, 412-438 (2020).
9. C. Abbo et al., Psychological distress and associated factors among the attendees of traditional healing practices in Jinja and Iganga districts, Eastern Uganda: a cross-sectional study. Int J Ment Health Syst 2, 16 (2008).
10. N. Amit et al., Relationship between debt and depression, anxiety, stress, or suicide ideation in Asia: a systematic review. Frontiers in psychology 11, (2020).

Competing Interests: TR has received consultancy fees, royalties and shares for his work with two software companies for helping developing interventions around financial difficulties and mental health problems. CF has undertaken a programme of research, training and intervention with financial services organisations and essential services such as gas companies on mental health. The remaining authors have no conflicts of interest to declare.