I woke up to the devastating news that noted Chef and journalist Anthony Bourdain was found dead. The Wall Street Journal reports of an apparent suicide. This shocking news comes on the heels of another high profile suicide by designer Kate Spade. There are many people struggling with mental health, depression and suicidal thoughts will not make the headlines or be featured on the TV entertainment shows. The Centers for Disease Control (CDC) finds that suicide rates have climbed dramatically since 1999. You might wonder why an atmospheric scientist that contributes to Forbes on weather and climate is talking about suicide in this space. During difficult circumstances, writing is often a way for me to express my thoughts and help others. While more significant factors are associated with suicide, there is scientific evidence that that weather and late Spring-Summer are among them.
To be crystal clear, this article in no way intended to suggest that weather or seasonality is a dominant risk factor for suicide. The CDC website notes that “a combination of individual, relationship, community, and societal factors contribute to the risk of suicide.” The factors listed by the CDC include: family history of suicide or mistreatment, previous suicide attempts, mental illness, alcohol or substance abuse, aggressive or impulsive tendencies, religious or cultural beliefs, feeling isolated, loss, illness, barriers to mental health treatment, and the stigma associated with perceptions of mental health. Researchers have noted that race, discrimination and other social disparities may also amplify the risk of suicide.
In 2014, a paper was published in the International Journal of Environmental Research and Public Health entitled “Association of Weekly Suicide Rates with Temperature Anomalies in Two Different Climate Types.” In the study, scientists examined weekly suicide death totals and anomalies from Toronto, Ontario, Canada (1986–2009) and Jackson, Mississippi, USA (1980–2006). They found, for both cities, that cooler weeks showed a lower probability of experiencing high-end suicide totals. Warmer weeks had an increased likelihood of being associated with high-end suicide totals. The study, led by Dr. Grady Dixon at Ft. Hayes State University, says in the abstract,
Weekly suicide totals demonstrate a sufficient association with temperature anomalies to allow some prediction of weeks with or without increased suicide frequency. While this finding alone is unlikely to have immediate clinical implications, these results are an important step toward clarifying the biopsychosocial mechanisms of suicidal behavior through a more nuanced understanding of the relationship between temperature and suicide.
Such linkages have long been debated in the academic literature. A 2007 study in The American Journal of Epidemiology conceded a minor association between weather and suicide but challenged the notion of its significance. More recent studies, however, continue to find relationships with temperature. A 2017 paper in the Proceedings of the National Academy of Sciences highlighted increased suicide rates in India due to crop-damaging temperatures. A 2016 study published in Environmental Health Perspectives found consistent positive associations between warmer temperatures and suicide in 3 East Asian countries, regardless of country, age and gender. Dixon and his colleague Adam Kalkstein recently followed up their 2014 study with a 2018 study in The International Journal of Biometeorology. In that study they examined 9 major cities: Cook (Chicago), Fulton (Atlanta), King (Seattle), Los Angeles (Los Angeles), Maricopa (Phoenix), Miami-Dade (Miami), Philadelphia (Philadelphia), Salt Lake (Salt Lake City), and St. Louis (St. Louis). They found that above average temperatures were associated with increased suicide risk in all counties and that there was a tendency towards late spring/summer peaks.
While temperature has been the primary meteorological factor associated with suicide, several studies have also looked at duration of sunlight and seasonality. A 2017 study published in Progress in Neuro-Psychopharmacology and Biological Psychiatry supports the hypothesis that sunshine has an increasing effect on the risk of suicide, but authors noted that it was “prompt” and “weak.” A 2016 study in The Journal of Affective Disorders entitled, “Do suicide attempts occur more frequently in the spring too? A systematic review and rhythmic analysis.” reviewed 29 science articles from 16 countries. A variety of seasonal patters were observed, but suicide attempts were found to be most frequent in spring and summer. This result is consistent with findings dating back to the 1800s as well as Dixon and Kalkstein’s study of 9 U.S. cities. This may seem counterintuitive because of the perceptions associated with the cold, winter months with less sunlight. Annie Hauser, writing in Weather.com, talked with Professor Grady Dixon in 2014 and writes,
Spring is when severely depressed people are able to be motivated enough to take action and do something. In most people, depression creates overwhelming feelings of listlessness and disinterest, so the idea of putting together a plan to commit suicide is too difficult during the winter, when depression symptoms may be worse in some people, he (Dixon) said. “Another hypothesis: [Patients] know how they’re affected by seasonal winter depression. They anticipate they’ll feel better when spring and summer roll around,” Dixon said. “When they don’t, that’s a catalyst for suicide.” One of the oldest theories holds that people who are depressed and withdrawn during the winter don’t bounce back in spring, like many of other people do.
Another more speculative theory about spring and suicides is inflammation. Inflammation is related to heart disease and an array of potential fatal diseases. Dr. Adam Kaplin is a psychiatrist at Johns Hopkins University. He told the New York Times a few years ago that speculative research has linked inflammation with exacerbation of depression. Spring colds and allergy can lead to inflammation.
At the end of the day, all of these relationships are complex. More research and awareness is required. I will end with this:
National Suicide Prevention Lifeline, Call 1-800-273-8255, Available 24 hours everyday