Sunshine has always been associated with bright thoughts, happy feelings, and elevated moods. Meanwhile, a study conducted in Austria has linked sunshine to suicide, not as a preventive factor, but as a risk factor.
To clarify, the researchers from the University of Vienna confirmed that exposure to sunshine over a short period of time can be a risk factor to suicide, yet it can lower the risk over several months if exposure is regular.
According to Dr. Matthaeus Willeit, the study's lead author, there is no reason to avoid the sun's rays simply based on the findings of the study. However, people might want to consider it as a factor that influences suicide risk.
Dr. Willeit added that suicide is complicated and has no one single cause, rather, a bunch of risk factors.
So what brought about the conclusion that sunshine is among these factors? The researchers studied the information of 69,462 recorded suicide cases, which occurred in Austria between January 1970 and May 2010. The data was then put side by side with data gathered from 86 weather stations that recorded the daily hours of sunshine.
Results revealed that there is a correlation between the number of suicides per day and the amount of sunshine. To account for seasonal variations, the researchers adjusted the numbers, only to discover that suicide risk increased along with the amount of sunshine over the first 10 days. However, suicide risk decreased along with continued sun exposure between 14 to 60 days.
With these findings, the researchers speculate that it has a lot to do with serotonin, the feel-good neurotransmitter. Sunlight affects serotonin levels in the body, influencing impulsivity, mood, and aggression. These play a role in suicidal ideation and behavior.
Like an antidepressant, sunlight's short-term effects may be causing impulsivity first, then mood. This may explain why the long-term effect of sunlight may be a lower suicide risk; as mood stabilizes, suicidality decreases, said the researches.