Okay, I have to confess. I’ve definitely not been my, shall we say, “best self” this week.  I’ve been cranky, lazy, and short tempered.  We don’t have air conditioning in my house and we’ve been under a prolonged “heat dome”  here in Northern California.  Usually I can make it through a day or two of 100 degrees maintaining my dignity, but as this heat wave has stretched on for a week, it’s definitely getting to me.  I’m thinking I’m not alone  as I’ve watched the temperatures soar in other parts of the country and all around the world this summer.  So to ease my conscience, I did a little poking around on the effect of heat on mental health.

Yup,  no surprise, heat effects it!  According to the American Psychiatric Association, the combination of the effects on our physical health and mental health is actually profound during a heat wave.  Emergency rooms quickly fill up with patients experiencing dehydration, delirium, and fainting.  Heat waves are also linked to a rise in depressive symptoms and anxiety.  There is also a link between daily high temperatures and suicide and suicide attempts.  For every 1 degree Celsius increase in monthly average temperature, mental health related deaths increase by 2.2%!  Spikes in relative humidity also result in a higher occurrence of suicide.  People who have bi-polar disorder or schizophrenia also are more prone to manic or psychotic episodes during times of increased heat, leading to more psychiatric hospitalizations.  Interestingly, the effectiveness of psychiatric drugs can be reduced when people are dehydrated, leading to changes in mood and functioning, as well.

Even those without a mental health disorder can have their mental health affected, including the ability to think and reason (hah, don’t I know it).  Research shows the areas of the brain responsible for framing and solving complex cognitive tasks are impaired by heat stress.  When people are not thinking clearly due to heat, it’s more likely they will become frustrated, which in turn, leads to a higher likelihood of aggression.  There is strong evidence linking extreme heat to violent crime.  Even just a one or two degree celsius increase in temperature can lead to a 3- 5% spike in assaults.  Episodes of domestic violence jump during heat waves.  

There are several things that may be underlying these changes.  Research shows that there is a complex interaction of psychological, social, and biological factors.  For instance, a brain chemical called serotonin, which regulates mood and is involved in keeping levels of aggression in check, is affected by high temperatures.  When it is hot, people tend to increase their use of alcohol and this can contribute to poor judgment or impulsive behavior.  Most people can’t sleep well when it’s hot, which also has a strong effect on people’s mood and judgment.  Over a period of days the lack of sleep can compound, making people prone to accidents and cloudy thinking.  And of course, certain people are more vulnerable to heat than others, due to occupations, living circumstances, stress levels, and hormones.  In a study by Obradovich and Paulus, the authors found that those with lower incomes were more effected by heat and women experienced worse effects than men.  Combined, they found that the effect of heat on mental health was twice as bad for low-income women as it was for high income men.  

Obviously it’s so important to protect yourself as best as possible during a heat wave, including staying hydrated and avoiding the heat exposure as much as possible.  But some good news?  Research shows a powerful protective effect when people are looking out for other people.  Neighbors checking in on neighbors and community care opportunities, like gathering at libraries or cooling centers, had a significant positive impact on reducing mental and physical health crises in both children and adults.  One piece of advice, though, from my own experience?  I welcome the caring, but just don’t get too close!