Heat and Mental Health in Cities

Abstract

AbstractExtreme heat wave events (EHE) are one of the most unprecedented threats posed by climate change. The escalation of global temperature is expected to cause more frequent and prolong heat waves which may have a disastrous impact on the human population and the ecosystem. Currently, more than 50% of the world population lives in urban areas and is expected to increase to 6.4 billion by 2050. Global climate change with the local urban heating phenomenon in cities is expected to impose immense threat in terms of increased surface temperature affecting the urban well-being and livability status. While the different aspects of climate change may affect urban health through direct and indirect pathways, the implications of heat toward mental health are less studied. High ambient temperatures have a range of mental health effects. A study conducted in 19 different countries suggested a significant relationship between heat and psychological conditions where heat stress and consistent exposure to high temperature were found to cause depression and anxiety. Other scholarly studies found an increase in mental and behavioral disorder reports during heat wave period. The strongest evidence was found for increased suicide risk. Six broad mental health outcome categories were identified: suicide and heat; bipolar disorder, mania and depression, and heat; schizophrenia and heat; organic mental health outcomes and heat including dementia; alcohol and substance misuse and heat; and multiple mental health outcomes/mental health service usage and heat. A review from fifteen studies showed an increased suicide risk with heat (relative risk (RR) 1.014–1.37 per 1 °C, P < 0.05; r = 0.10–0.64, P < 0.05). Increased risks of mental health-related admissions and emergency department visits at higher temperatures were also found. Despite mounting evidence that mental health treatments are essential, especially during EHE, mental health services are found to be scarce in most developing and low-income nations. Raising public awareness of the consequences of EHE on mental health is critical to educate people on how to reduce risks and safeguard mental health. However, understanding the people's attitudes and behaviors on EHE is the first step in developing a more targeted public awareness program. As a result, individual-level research is required to identify vulnerable populations and assist in the development of adaption strategies, such as heat action plans. In summary, evidence for the impact of heat on other mental health outcomes was mixed. Knowledge gaps exist on the impact of high temperatures on many common mental health disorders. Mental health impacts should be incorporated into plans for the public health response to high temperatures.KeywordExtreme heat eventMental healthSustainable citiesUrban healthUrban heat island