Psychiatry, like retail, has busy seasons. Unlike retail, psychiatry’s hectic periods occur secondary to fluctuations in seasonal light exposure, rather than during major holidays. For years, I treated patients for worsening, or new onset depression, around Halloween, October 31. Some of this was Seasonal Affective Disorder, some simply the effects of diminishing light exposure on pre-existing depression. This Halloween effect began shifting forward about 15 years ago. Instead of an influx of depressed patients November 1, they began showing up December 1. What could account for this? Depression is driven, partly, by circadian rhythms, specifically light exposure. As the planet warmed, more people stayed outside in the fall, increasing their light. By December 1, it was cold enough that outdoor light exposure diminished, and patients again showed up at my office, depressed.
It was this Halloween phenomenon, which first sparked my interest in the intersection of mental health and climate change.
Looking out my window as I write, the wisteria wrapping around my porch is blooming, the yard is lush. There is a cool breeze. It is a lovely spring. Climate change seems a future problem. But it is not.
There is a growing body of research on the effects of climate change on health. Less is known about the effects of a warmer planet on mental health. What follows is a summary of some of the research on climate change and mental health.
Climate change events are acute (hurricanes, flooding) sub-acute (drought) and chronic (rising sea levels, increasing temperatures) These climate hazards lead to a variety of consequences which are occurring now-regardless of the lavender wisteria in my backyard- and are disproportionally affecting those populations least able to cope.
Mental health consequences of exposure to weather disasters
Instinctively we understand the impact of weather on well-being. Days of gray, rainy weather are depressing. Extreme heat makes us cranky. Strong thunderstorms with high winds are scary. It isn’t much of a stretch, then, to understand the impacts of extreme weather events on mental health. Specifically, exposure to weather disasters results in increases in new-onset psychiatric diagnoses. Hurricanes, floods and wildfires have been studied most extensively. All increase PTSD, depression and anxiety for those affected. Grief/bereavement, increased substance abuse, aggression and suicidal thoughts also increase in the wake of extreme and catastrophic weather.
Following Katrina, veterans with pre-existing mental illness developed a 6.8 times greater risk for developing any mental illness.
Increased rates of interpersonal violence and domestic abuse are observed following climate related disasters.
In Miami, following Hurricane Andrew, the murder-suicide rate in Dade County doubled in the 6 months following the hurricane.
Extreme heat causes an increase in aggressive behavior and suicide with an increase in ed and hospital admissions.
Long term drought doesn’t result in PTSD, but…
Drought has far-reaching and long-term impacts on rural populations, particularly farmers. While it is not possible to draw a direct causal link between climate change and stressed and depressed farmers, a 2015 review found that “the most prominent causal pathway linking drought and mental health is via the economic effects from land degradation.”
Australia is in the midst of a mental health crisis among its farmers, who are experiencing alarming increases in depression.
Long-term drought is also linked to conflict and forced migration. The Syrian civil war and subsequent implosion is linked to agricultural failures and drought. The United Nations estimates that an increasingly uninhabitable planet will create between 25 million to 1 billion new climate migrants.
The existential impact of climate change
The idea of climate change, and media reports about climate, which may dramatize the risk, also causes a heightened risk perception leading to anxiety and despair. I’ve had melancholy conversations with middle-schoolers to millennials frightened for their futures. My cohort won’t live long enough to see the coastlines under water, but that’s not true for our grandchildren, perhaps our children.
Fortunately, 80% of persons affected by PTSD/depression/anxiety secondary to extreme weather events will recover. We have no idea what living under the threat, the prospect, of a wildly inhospitable planet will do to our children.
Which groups are most at risk?
Populations most at risk from climate change include children, women (especially pregnant and post-partum mothers), and the poor, elderly and first responders.
Children have significantly more persistent PTSD symptoms than adults two years post disaster.
There were 56,100 pregnant women exposed to Hurricane Katrina. Those women with a high exposure to the hurricane had a significantly increased risk for PTSD and depression. Consequences of catastrophic weather include lack of access to clean drinking water, poor hygiene, compromised food sources, all of which contribute to severe stress in pregnant women and mothers. Increases in vector borne disease affect both pregnant women and young children.
The elderly, with higher rates of physical infirmity and depression, can be expected to have more difficulty responding to weather catastrophes. Extreme heat is also an issue, as older persons are more vulnerable to heat stress.
The economically disadvantaged have a higher risk of finding themselves in crosshairs of extreme weather events due to sub-standard housing (it’s always trailer parks, not gated communities which are demolished by tornados) and less ability to respond to these events.
First responders involved in rescue, recovery and cleanup following extreme weather events are at heightened risk of PTSD. “In a study of Coast Guard responders to Hurricanes Katrina and Rita, local responders were three times more likely to report depression than those who were not local.”
Finally, the mentally ill take it on the chin following extreme weather events, for several reasons. Having a pre-existing mental illness, by definition, means the sufferer lacks boundless resilience. Exacerbations of previously stable mental illnesses are likely.
Extreme heat targets the mentally ill
Individuals with mental illness have triple the risk of death, compared with non-mentally ill, during heat waves. This is a result of multiple factors: lack of cooling resources, innate poor thermoregulation secondary to schizophrenia, and psychiatric meds, some of which impair heat regulation.
“After the 2012 heat wave in Wisconsin, nearly 52% of the heat-related deaths studied occurred among people with at least one mental illness, and half of those were taking a psychiatric medication.”
This is a grim post, and as I was writing it, I became less and less enthusiastic about the subject, which seemed like an interesting issue to blog about when I signed on. I’ll leave you with the few antidotes to climate despair I learned about while doing the research.
Do what you can for the planet-any action is better than hopelessness.
Get out in nature as often as possible.
Media plays an outsize roll in creating climate hopelessness/helplessness. Stay informed but be aware that media may not always present a balanced picture.
The research for this blog came from two sources, both of which I encourage you to read.
Climate Change an mental health: risks, impacts and priority actions. Int J Mental Health Syst 2018; 12:26
The Impacts of Climate Change on Human Health In the United States, health2016.globalchange.gov Chapter 8