Why is it that some people get angry at the littlest thing while others have the patience of Job?
New research from the University of Cambridge finds that low levels of serotonin in your brain have a major impact upon how you react to that jerk who cut you off in traffic this morning.
Building upon previous serotonin/aggression research, this study is the first to show how serotonin helps regulate behavior in your brain as well as why some people are more prone to aggression.
In this study, healthy volunteers’ serotonin levels were altered by manipulating their diet.
- On the serotonin depletion day, they were given a mixture of amino acids that lacked tryptophan, the building block for serotonin.
- On the placebo day, they were given the same mixture but with a normal amount of tryptophan.
The researchers then scanned the volunteers’ brains using functional magnetic resonance imaging (fMRI) as they viewed faces with angry, sad, and neutral expressions. Using the fMRI, they were able to measure how different brain regions reacted and communicated with one another when the volunteers viewed angry faces, as opposed to sad or neutral faces.
The research revealed that low brain serotonin made communications between specific brain regions of the emotional limbic system of the brain (a structure called the amygdala) and the frontal lobes weaker compared to those present under normal levels of serotonin.
The findings suggest that when serotonin levels are low, it may be more difficult for the prefrontal cortex to control emotional responses to anger that are generated within the amygdala.
Using a personality questionnaire, they also determined which individuals have a natural tendency to behave aggressively.
In these individuals, the communications between the amygdala and the prefrontal cortex was even weaker following serotonin depletion. ‘Weak’ communications means that it is more difficult for the prefrontal cortex to control the feelings of anger that are generated within the amygdala when the levels of serotonin are low.
As a result, those individuals who might be predisposed to aggression were the most sensitive to changes in serotonin depletion.
What Does This Mean to You?
It means that if you don’t want to live your life being Mr. or Ms. Grumpy, you may want to take steps to avoid low serotonin.
- Actively thinking positive thoughts (mind over matter)
- Develop techniques to handle stressful situations (more mind over matter stuff)
- Exposure to bright light
- Dietary changes – Whey protein with alpha-lactalbumin has a strong effect