Figure 1
Methodological framework to explore the economic relationships between the prevalence and costs of mental health and selected environmental factors.
Table 1
Definitions and sources of data used in the country level analysis.
| VARIABLE | DEFINITION | SOURCE | MEAN | S.D. |
|---|---|---|---|---|
| DALY rate | Number of mental health DALYs per 100,000 people 2019 | Global Burden of Disease | 1,689.59 | 328.27 |
| GDP per capita | Gross Domestic Product per capita 2019 (USD; thousands) | World Bank | 17.34 | 24.04 |
| Inequality | Index of inequality (0–10) | INFORM Risk | 4.04 | 1.95 |
| Healthcare inaccessibility | Index of inaccessibility to healthcare (0–10) | INFORM Risk | 4.13 | 2.45 |
| Hazard exposure | Composite index comprising data on hazards, exposure, vulnerability and coping capacity (0–10) | INFORM Risk | 3.75 | 1.77 |
| Air pollution | PM2.5 mean annual exposure (micrograms per cubic meter) | World Bank | 27.08 | 18.83 |
| Access to green space | Proportion of population living in urban areas (%) | World Bank | 60.56 | 23.41 |
[i] See Appendix 1, Table A1.1 for further information.
Table 2
Statistically significant relationships from regression model of rates of mental disorders as a function of environmental, economic and socio-economic factors.
| REGRESSION COEFFICIENT | |
|---|---|
| GDP per capita | 3.57 |
| Income inequality | 38.07 |
| Healthcare inaccessibility | –94.06 |
| Hazard exposure to extreme natural disasters | 42.68 |
| Air pollution | 2.12 |
| Access to open (green) space | 3.53 |
[i] Note: Dependent variable is the number of DALYs per 100,000 people.
Full regression model is given in Appendix 1, Table A1.2.
Figure 2
Categorisation of mental illness used to quantify the relationship between the costs of mental illness and a set of explanatory variables, including environmental factors.
Table 3
Definitions and sources of data used in the cost of illness analysis.
| VARIABLE | DEFINITION | SOURCE | MEAN | S.D. |
|---|---|---|---|---|
| Cost/DALY (ln) | Cost of illness per DALY (USD; PPP adjusted; 2020 price level; natural log) | Adapted from Christensen et al. (2020) | 6.50 | 2.61 |
| Severe disorders | Binary variable indicating severe disorder (1 = severe; 0 = common) | Christensen et al. (2020) | 0.21 | 0.41 |
| Productivity costs | Binary variable indicating measure of productivity loss (1 = productivity loss; 0 = other costs) | Christensen et al. (2020) | 0.09 | 0.29 |
| Societal costs | Binary variable indicating measure of societal costs (1 = societal costs; 0 = other costs) | Christensen et al. (2020) | 0.46 | 0.50 |
| GDP per capita (ln) | GDP per capita (USD; PPP adjusted; 2020 price level; natural log) | World Bank | 10.80 | 0.55 |
| Hazard exposure | Composite index natural hazards (0–10) | INFORM Risk | 3.36 | 1.79 |
| Air pollution | Proportion of population exposed to PM2.5 air pollution levels exceeding WHO guideline value | World Bank | 11.58 | 6.28 |
| Access to green space | Proportion of population living in urban areas | World Bank | 78.46 | 10.40 |
[i] PPP = Purchasing Power Parity.
Table 4
Cost of mental illness and development disorders, categorised by type of disorder.
| MEAN COST (US$/DALY) | |
|---|---|
| Common disorders | 4,849 |
| Severe disorders | 11,399 |
| Childhood disorders | 62,071 |
| Childhood + development disorders | 1,120 |
| Total | 13,940 |
[i] Note: Data taken from 48 countries in Christensen et al. [30].
See Appendix 1, Table A1.3 for further statistical results.
Table 5
Cost of mental illness and development disorders, categorised by type of cost.
| MEAN COST (US$/DALY) | |
|---|---|
| Healthcare costs | 2,072 |
| Productivity losses | 9,210 |
| Total societal costs | 25,862 |
| Other costs | 7,036 |
| Total | 13,940 |
[i] Note: Data taken from 48 countries in Christensen et al. [30].
See Appendix 1, Table A1.4 for further statistical results.
Table 6
Relationships from regression model of costs of mental illness as a function of environmental, economic and socio-economic factors.
| REGRESSION COEFFICIENT | |
|---|---|
| Severe disorders | 1.86 |
| Productivity costs | 1.76 |
| Societal costs | 2.56 |
| GDP per capita (ln) | 0.57 |
| Hazard exposure | 0.16 |
| Air pollution | –0.01 |
| Accessibility to green space | 0.00 |
[i] Note: Dependent variable is US$ per DALY at 2020 price level.
Statistically significant relationships are given in bold.
Full regression model is given in Appendix 1, Table A1.5.
Table 7
Estimated additional annual total cost of mental illness attributable to climate change, air pollution and access to green space, by World Bank region.
| WORLD BANK REGION | COST(US$ MILLIONS, 2020 PRICE LEVEL) | |||||||
|---|---|---|---|---|---|---|---|---|
| 2030 | 2050 | |||||||
| CLIMATE CHANGE COST | AIR POLLUTION COST | GREEN SPACE COST | TOTAL COST | CLIMATE CHANGE COST | AIR POLLUTION COST | GREEN SPACE COST | TOTAL COST | |
| East Asia & Pacific | 9,739 | 1,666 | 2,490 | 13,896 | 79,128 | 10,919 | 15,318 | 105,366 |
| Europe & Central Asia | 1,679 | 54 | 217 | 1,950 | 15,524 | 476 | 1,851 | 17,851 |
| Latin America & Caribbean | 1,187 | 18 | 163 | 1,368 | 9,460 | 101 | 1,114 | 10,674 |
| Middle East & North Africa | 1,494 | 312 | 189 | 1,995 | 21,229 | 3,370 | 2,545 | 27,143 |
| North America | 2,422 | 11 | 190 | 2,622 | 22,612 | 85 | 1,598 | 24,295 |
| South Asia | 4,928 | 17,110 | 798 | 22,836 | 63,411 | 236,464 | 11,133 | 311,008 |
| Sub-Saharan Africa | 1,799 | 85 | 333 | 2,217 | 33,918 | 858 | 5,471 | 40,247 |
| Global | 23,248 | 19,255 | 4,380 | 46,884 | 245,282 | 252,273 | 39,029 | 536,584 |
Figure 3
Estimated additional total annual cost of mental illness attributable to climate change, air pollution and access to green space.
Notes: Groupings are following World Bank regional classifications.
Figure 4
Percentage change in annual societal costs of mental illness attributable to changes in climate hazards, air pollution and access to green space in 2050 relative to 2020.