Stressed and depressed: Climate change and mental health in Bangladesh

Climate change poses a number of mental health consequences such as heat stress and infectious and vector-borne diseases among a host of other issues. While these have been documented to a certain extent, the effects of climate change on common mental health conditions, such as depression and anxiety, have not been studied as extensively. One of the major reasons is due to mental health being stigmatized in many parts of the developing world, including Bangladesh. Additionally, studies that do exist tend to focus on post-disaster scenarios and do not represent the overall population.

The World Bank and Georgetown University recently conducted a study which was published in The Lancet Planetary Health. The study assesses, for the first time, the prevalence of mental health issues such as depression, generalized anxiety disorder, or the simultaneous presence of both conditions in a representative population in Bangladesh. The findings also show the relationship between weather variables and exposure to extreme natural events to these events.

Key findings

1. Prevalence: Our study suggests that on average, 16 percent of the overall population (over the age of 15 years) experience depression, 6 percent have an anxiety disorder and 5 percent suffer from the co-presence of both conditions. There is a positive relationship between the presence of depression and anxiety and age.
    
2. Gender and Geography: While women report a marginally higher prevalence of depression, men are more prone to anxiety. In terms of the prevalence of depression and anxiety disorders across geography, individuals in urban hubs, are considerably more likely to report both conditions than elsewhere in the country.
    
3. Seasonality: Lastly, in terms of seasonality, while depression is more prevalent during the winter (18 percent) than during the summer (14 percent), marginally higher rates of anxiety disorders are reported during the monsoon (7 percent) than during the dry season (6 percent).

Climate Change and Mental Health

We find that while seasonality (summer vs. winter) does not appear to play a significant role: An individual experiencing a 1°C higher temperature during the two months preceding the survey rounds has a 21% higher probability of reporting an anxiety disorder and a 24% higher likelihood of experiencing both depression and an anxiety disorder at the same time. Similarly, a 1 g/m³ increase in humidity over the same duration is associated with a 6% higher probability of reporting co-presence of both conditions. Lastly, exposure to natural disasters brought on by climate change, such as flooding, is associated with increased odds of all conditions – depression by 31%, anxiety by 69%, and co-presence of both conditions by 87%.

As a country that is particularly vulnerable to the impacts of climate change, Bangladesh is already experiencing the effects. The average temperature has increased by an average of 0.5°C between 1976 and 2010 in the country, accompanied by changing rainfall patterns, and higher incidences of extreme weather events such as heat waves, cyclones, floods, convective storms, tidal surges, and river erosion.

As climate change accelerates, so will its deteriorative effects on mental health, and is likely to have significant and wide-ranging implications, both for individuals and at a national level. For individuals, mental health conditions can have physiological manifestations, increasing out-of-pocket expenses, and negatively impacting the quality of life, and productivity. At a national level, these effects can lead to an increased financial burden of healthcare, hinder economic growth, and raise levels of poverty. The brunt of these effects will likely be felt more by lower-middle-income countries such as Bangladesh. Therefore, the need to address this issue is urgent and requires immediate action.

Read the publication in Lancet Planetary Health.