Mental Health Impacts of Climate Change: A Transdiagnostic Approach – Part II

As discussed in Part I (link), mental health can be significantly impacted by climate change. Part II will describe how various mental health disorders intersect with climate change

Symptoms of Depression, Major Depressive Disorder, and Climate Change

Climate change can have both direct and indirect effects on symptoms of clinical depression (Ellis & Albrecht, 2017; Ginexi et al., 2000; Ruskin et al., 2018; Shultz et al., 2019; Speldewinde et al., 2011). In some cases, climate-related events or consequences can result in a diagnosis of major depressive disorder (MDD; Chen et al., 2019; Ellis & Albrecht, 2017; Hansen et al., 2008; Shultz et al., 2019; Silveira et al., 2021; Speldewinde et al., 2011; To et al., 2021). Exposure to acute extreme weather events (EWE), such as floods (Ginexi et al., 2000), hurricanes (Ruskin et al., 2018), and wildfires (Silveira et al., 2021; To et al., 2021) are all linked to depressive symptoms. Additionally, there are documented associations between long-term heat exposure and incidence of mood disorders, including MDD (Chen et al., 2019; Hansen et al., 2008). 

Especially for those whose home environment is a major part of their income, social network, or self-identity (e.g., farmers, Indigenous peoples), the risk of developing symptoms of depression is particularly high when faced with the threat of climate change or place-based distress (Burke et al., 2018; Ellis & Albrecht, 2017; Ginexi et al., 2000; Speldewinde et al., 2011). Australian environmentalist Glenn Albrecht coined the term “solastalgia” to conceptualize the pain or distress caused by the loss or change of someone’s home environment due to physical degradation (Albrecht et al., 2007, p. S96).

Financial plight seems to be an indirect pathway that climate change can affect depressive symptoms, like lack of access to medical care after a disaster (Ruskin et al., 2018). Even after controlling for pre-disaster depressive symptomology, participants with the lowest incomes affected by the 1993 Midwest floods had sharper increases in their depressive symptoms compared to those with higher incomes, indicating that the floods and their consequential impact disproportionately affect those in lower income brackets (Ginexi et al., 2000). 

Although there have been many studies associating singular-event natural disasters with mood disorders like depression (Ginexi et al., 2000; Goenjian et al., 2001; Trombley et al., 2017), cumulative environmental changes due to the climate crisis seem to be more of a threat. In a 2016 study, researchers found that compared to the less severe mental health impacts (i.e., short-term PTSD symptoms) of rapid-onset and short-duration EWEs, the progression of climatic changes, like rising sea-levels and severe droughts, are associated with more serious and persistent mental health issues, such as suicidality and depression (Garcia & Sheehan, 2016). For instance, someone who experiences property damage due to a rapid-onset natural disaster, such as an earthquake, may only experience stress related to rebuilding property. In contrast, someone who experiences lasting climatic changes, such as a severe drought causing land to become inhabitable, may experience more chronic stressors, including navigating permanent displacement and rebuilding a social support network.

Suicidality and Climate Change

There is a well-documented relationship between increased ambient temperature and suicide risk (Basu et al., 2018; Burke et al., 2018; Carleton, 2017; Dixon et al., 2014; Fountoulakis et al., 2016; Gao et al., 2019; Hanigan et al., 2012; Helama et al., 2013; Kalkstein et al., 2019; Kim et al., 2016, 2019; Ngu et al., 2021; Palinkas & Wong, 2020; Thompson et al., 2018). Many studies have found that suicide risk has seasonal associations with an increase in suicide risk during the spring and summer (Fountoulakis et al., 2016; Hanigan et al., 2012; Marion et al., 1999; Partonen, 2004; Preti et al., 2007; Rocchi et al., 2007; Yang et al., 2011). In one study with a sample size of more than 95,000 individuals, a significant positive association between suicides and temperature was found with a clear peak in the spring season (Preti & Miotto, 1998). In another study that analyzed over 1.3 million suicides, researchers found that the risk of suicide increased alongside the increasing ambient temperature in many countries (Kim et al., 2019).  Weather and climate anomalies, such as abnormally warm days in the winter, are also positively associated with suicide risk (Basu et al., 2018; Dixon et al., 2014; Preti et al., 2007), especially for those who have strong connections to the land. In fact, for the Inuit peoples of subarctic North America, fall freeze-ups and early spring thaw are the most vulnerable time of the year for people’s mental health as this causes disruptions in Inuit land-based activities, land productivity, and ultimately threatens the culture and lifestyle of this resource-dependent community (Willox et al., 2013). Similarly, crop-damaging climate phenomena like drought affect resource-dependent communities, like farmers and their families (Hanigan et al., 2012). In addition to abnormal weather, heatwaves and natural disasters (especially continued exposure to natural disasters) are both associated with increased suicidal behavior (Ngu et al., 2021; Page et al., 2007; Reifels et al., 2018; Thompson et al., 2018). 

Generalized Anxiety Disorder and Climate Change

Although there is a clear distinction between climate change anxiety (CCA) and generalized anxiety disorder (GAD), many studies have indicated a positive correlation between CCA, GAD, and other anxiety symptoms (Cosh et al., 2024; Gebhardt et al., 2023; Hajek & König, 2023; Hepp et al., 2023; Hogg et al., 2021; Parmentier et al., 2024; Pihkala, 2020; Plohl et al., 2023; Schwartz et al., 2023; Searle & Gow, 2010; Stanley et al., 2021; Wu et al., 2023). Interestingly, a 2023 study found that symptoms of GAD were the most important predictors of CCA, indicating that those who tend to be more anxious are more likely to experience CCA (Asgarizadeh et al., 2023). Multiple factors may contribute to this connection, such as having an intolerance of uncertainty, having prior experience with climate-related events, pro-environmental orientation, being a student studying the environment, worry and risk perception, media exposure, future orientation, and identifying with a younger generation (Asgarizadeh et al., 2023; Bourban, 2023; Cosh et al., 2024; Parmentier et al., 2024; Pihkala, 2020; Searle & Gow, 2010). Trauma from environmental-related displacement is also associated with GAD (Shultz et al., 2019), along with people who have experienced natural disasters (Ruskin et al., 2018; To et al., 2021). Additionally, researchers found an increase in hospitalizations for adolescents with existing anxiety disorders on days with high temperatures (Niu et al., 2023).

Obsessive-Compulsive Disorder and Climate Change

As the climate warms, the planet becomes a more suitable environment for the transmission of diseases such as dengue, West Nile virus, malaria, and vibrio (Romanello et al., 2024). Data from 2021 studies indicate that the COVID-19 pandemic exacerbated symptoms of obsessive-compulsive disorder (OCD) for individuals who are clinically diagnosed and the general public (Cunning & Hodes, 2022; Guzick et al., 2021). There was a worsening of contamination-OCD symptoms, such as excessive hand-washing, as well as other manifestations of OCD, like restocking supplies and checking the news (Subramaney et al., 2022). Another study with a large sample size of 742 respondents found a relationship between hot weather and worsening OCD symptoms, indicating that higher ambient temperatures may exacerbate OCD even without the threat of disease or contamination (Brierley et al., 2021).

Interestingly, one study found an association between OCD symptoms and obsessions about one’s contribution to the climate crisis. In fact, over a quarter of participants with a checking subtype of OCD had climate change-related checking concerns such as obsessively checking light switches and stoves to conserve energy, obsessively checking the tap to make sure they are not wasting water, and even checking pet water bowls to ensure the water had not evaporated in hotter temperatures (Jones et al., 2012).

Substance Use Disorders and Climate Change

There are many well-documented studies regarding the association between natural disasters and substance abuse among both adults and adolescents (Agyapong et al., 2018; Bandla et al., 2019; Brown et al., 2019; Flory et al., 2009; Kane et al., 2018; Rohrbach et al., 2009; Temple et al., 2011; Wagner et al., 2009). Following an Australian wildfire, researchers found a significant association between exposure to the natural disaster and increased tobacco use in a large sample of young adults (N = 2063), regardless of whether or not they experienced symptoms of PTSD (Parslow & Jorm, 2006). However, climate change and the consequential increased frequency and severity of natural disasters can also have an indirect influence on the development of substance use disorders (SUD). For example, post-disaster financial and psychosocial stress seem to be predictive of SUD in people affected by natural disasters, suggesting that people experiencing low socioeconomic status are more at-risk for developing SUD (Flory et al., 2009; Rohrbach et al., 2009). Further, in their article on opioid use and heatwaves, Ryus and Bernstein (2022) describe how the climate crisis can exacerbate existing inequalities and put people with SUD more at risk.

The opioid crisis and climate change have the potential to interact synergistically to contribute to excess burden of death and disease. Socioeconomic marginalization places people with opioid use disorder at greater risk for death and injury due to inadequate access to air conditioning. (p. 1671)

There are a multitude of studies that document the strong association between SUD-related risks in hotter temperatures. Some studies have noted a significant increase in emergency department admissions for people with SUD in higher temperatures (Chang et al., 2023; Nori-Sarma et al., 2022; Parks et al., 2023), and other studies have documented SUD-related deaths in higher temperatures (Liu et al., 2021; Marzuk et al., 1998; Page et al., 2007; Ryus & Bernstein, 2022). Cusack et al. (2011) note that substances such as MDMA, methamphetamine, and cocaine all contribute to an increase in body heat, and alcohol and opioids can directly cause hyperthermia, putting people with SUD at greater risk during heat waves. Vergunst et al. (2023) note that young people are disproportionately vulnerable to climate change because of their susceptibility to mental illness, including substance misuse, as well as their prolonged exposure to climate change compared with older populations.

Psychosis and Climate Change

There are multiple identified pathways that climate change can impact the onset and/or experience of someone diagnosed with a psychotic disorder (Broome et al., 2005; Fekih-Romdhane et al., 2024; Gupta & Murray, 1992). Twin studies suggest that one’s environment may be more influential to someone’s risk of having a psychotic experience compared to genetic factors (Taylor et al., 2022). There are a few studies documenting greater instances of psychosis in migrants/refugees, suggesting that those who have been displaced by climate change-related factors (e.g., rising sea levels, resource conflict, natural disasters, etc.) are at a higher risk for developing psychosis (Brandt et al., 2019; Broome et al., 2005). Another study demonstrated a significant correlation between climate change anxiety and psychotic experiences, with death anxiety as a partial mediator (Fekih-Romdhane et al., 2024). The results of this study are particularly concerning because they suggest that the onset of psychosis is not only influenced by changes in the climate but even by the thought of climate change.

What seems to be the most common connection between psychosis/psychotic experiences and climate change has to do with increasing temperatures. Multiple studies have found an association between psychosis-related emergency hospital admissions and heat (Gao et al., 2019; Jahan et al., 2020; Martin et al., 2024; Shiloh et al., 2007; Thomas & Parameswaran, 2022). There have also been studies documenting a disproportionate amount of heat-related deaths for people with psychosis compared to the general population (Hansen et al., 2008; Page et al., 2012). Shiloh et al. (2005) found that mean hospital admission rates for schizophrenia are significantly higher in the summer. Researchers hypothesize that this is likely due to the role of antipsychotic medication and its inhibitory effects on thermoregulation. 

Eating Disorders and Climate Change

Rodgers et al. (2023) identified a few pathways that climate change can have an impact on eating disorders, such as food insecurity, warmer climates and bodily exposure, and eco-anxiety. Food insecurity has been linked to eating disorders, specifically bulimia nervosa, and potentially due to a population weight reduction influencing one’s preoccupation with weight and size (Hazzard et al., 2020). It has also been documented that warmer climates are associated with eating disorders likely due to bodily exposure and a preoccupation with one’s weight compared to others (Sloan, 2002). A study conducted by Hazzard et al. (2020) discovered in their analyses that there is an association between ambient temperature and anorexia, and another study found a peak in dieting and bodily dissatisfaction in the spring and summer time (Griffiths et al., 2022).

In her book on climate change and psychological resilience, Dr. Britt Wray identified behaviors termed “climate anorexia” and “climate orthorexia,” which are restrictive compulsions related to one’s carbon footprint and impact on the environment (Wray, 2022, p. 56). A few studies have also documented this association and some have found that vegetarianism and veganism are possible pathways that people restrict food intake to decrease their impact on the environment (Heiss et al., 2017; Runfola & Safer, 2024; Sergentanis et al., 2020).

There are similarities between vegetarians, vegans, and people with restrictive eating disorders (e.g., checking food labels, dietary exclusions). Consequently, individuals who do ascribe to these diets may be at a higher risk of developing an eating disorder (Dunn & Bratman, 2016). Additionally, individuals with restrictive eating disorders may use a lifestyle diet choice, such as veganism or vegetarianism, as a way to mask their behaviors under the cloak of a socially accepted decision (Zuromski et al., 2015). This makes assessment for pathology difficult for clinicians. 

Practice Recommendations and Next Steps

Addressing climate distress in a therapeutic setting is becoming increasingly normal, yet many mental health professionals do not feel equipped to address these clinical concerns (Trost et al., 2024). Additionally, many people – particularly those who are already disproportionately impacted by the climate crisis – do not have sufficient funding or resources to see mental health professionals (White et al., 2023). Luckily, there are other pathways people can take to address their eco-emotions, or emotional responses to climate change. One study found that internet-delivered cognitive-behavioral therapy (iCBT) can be effective in addressing climate distress. iCBT is promising as it increases accessibility to low-cost resources and can be tailored to individual concerns, characteristics, and comorbidities (Lindhe et al., 2023). People can also alleviate climate distress by spending time with and in nature, including in urban green spaces (Cuijpers et al., 2023; Willis et al., 2024). Additionally, Thomson and Roach (2023) found that connectedness to nature is associated with an increase in both individual and collective pro-environmental action. 

Now more than ever, it is important to implement safeguards to protect against disabling levels of climate distress and to develop practices that will encourage adaptability to the shifting climactic environment and encourage meaningful change, both individually and as a greater community. Explore the resources below for toolkits, guides, worksheets, books, and videos to remain up-to-date on the mental health impacts of climate change.

Mental Health and Climate Change Resources

Our Climate has toolkits and guides on how individuals can get involved. 

Climatementalhealth.net offers films, worksheets, and book recommendations as needed. 

The American Academy of Child and Adolescent Psychiatry  provides informational videos to get educated.