Extreme heat linked to increases in mental health ER visits: study

[Excerpt] Waves of extreme heat, which are on the rise due to climate change, are linked to an uptick in emergency room visits for mental health conditions, a new study has determined.

On such hotter-than-normal days over the past decade, emergency department check-ins for any mental health condition surged by 8 percent in comparison to days of optimal temperature, according to the scientists, who shared their results on Wednesday in the journal JAMA Psychiatry.

The authors also identified robust connections between such temperatures and emergency room (ER) visits for specific mental health conditions, including substance use disorders; anxiety- and stress-related disorders; mood disorders; self-harm; childhood-onset behavioral disorders and schizophrenia, schizotypal and delusional disorders.

While the implications of extreme heat for physical ailments have been well documented, the potential connection between elevated temperatures and mental health issues remains poorly understood, according to the authors.

To draw their conclusions, the scientists analyzed a pool of 3.4 million emergency department visits among 2.2 million adults in the contiguous U.S. during warm season months — May to September — from 2010 in 2019. About 57 percent of these individuals were women, with a median age of 51 years old.

Looking at links between extreme heat and emergency department visits for any type of mental health condition, the authors calculated an “incidence rate ratio” of 1.08 in comparison to a baseline of 1.0. This meant that mental health visits to the ER of any type experienced an 8-percent increase on such days.

For substance use disorders specifically, the ratio was also 1.08, while for anxiety and stress-related disorders it was 1.07; mood disorders were 1.07; self-harm was 1.06; childhood-onset behavioral disorders it was 1.11 and for schizophrenia, schizotypal and delusional disorders it was 1.05.

While associations were higher in men than in women, the authors found no evidence of differential links according to age groups, which they said contrasted previous findings.

The connection between heat and ER visits across a variety of mental health outcomes demonstrates that this external stressor is not likely specific to any one condition, Nori-Sarma explained.

“Rather, we think of it as exacerbating existing mental health conditions,” she said.

While the authors described their study as “filling an important gap in existing literature,” they also acknowledged its limitations.

For example, the scientists said that they did not consider meteorological conditions aside from heat, such as precipitation or cloud cover, which could also alter mental health. Data providing individual-level characteristics like race and ethnicity, socioeconomic means and occupation was not available, while the focus on ER visits meant focusing on severe mental health presentations only, the authors added.

In addition, the scientists said they could only access data on individuals who have commercial health insurance or Medicare Advantage, meaning that many lower-income patients could not be included. This absence may have led to a “skewing of the sample toward wealthier socioeconomic status” and could limit the generalizability of the study, according to the authors. 

“We do think that our study is an underestimate of the actual burden of high temperature on mental health since we rely on data among insured individuals, and we are missing the potentially very vulnerable population of uninsured individuals,” Nori-Sarma told The Hill.

“Our findings indicate that the needs for mental health services may be especially high during times when extreme heat is being predicted, giving us a leg up on preparing the healthcare system to address those needs,” Nori-Sarma added.

Extreme heat linked to increases in mental health ER visits: study