The Effects of Stress
September 27, 2011 in depression
In the 1960′s a famous psychologist conducted a series of tests that defined the term learned helplessness. A German Shepherd was placed in a metal cage and received shocks every day and night (this was before animal testing was looked down upon). After the reoccurring shocks the dog began to understand that he could not control them. Eventually the cage was opened but the dog failed to understand his options and learning had closed down. This demonstrates the profound effects stress plays on us.
Stress is a natural response that has allowed us to survive and evolve over the years. If we didn’t feel any stress when encountering a sabertooth tiger, you can bet we would probably end up as dinner. We are in a time where we don’t have to worry about encountering a sabertooth tiger, but the modern equivilent could be a taxi speeding towards us as we are crossing a crosswalk. Stress and adrenaline kicks in, which is a natural response that allows us to survive and make smart choices to life-threatening situations. With heightened pulse and adrenaline a chemical called cortisol comes into play which works to calm us down.
Too much stress can be damaging to our brains. When too much adrenaline is released blood pressure isn’t able to maintain regular surges. Rough spots on blood vessels results, following by scars. Sticky substances build up on these scars which can lead to clogging arteries, strokes, or heart attacks. I know I never thought chronic stress could do that. It makes sense that those who are under chronic stress have an elevated risk of strokes and heart attacks.
Chronic stress also decreases our number of heroic white-blood-cell soldiers which damages our immune system. It also reduces the amount of antibodies your body creates, which fight viruses. This supports the study that people who were stressed were three times more likely to get a common cold.
While light stress can help our brain to perform better, chronic stress has very negative effects. The hippocampus has cortisol receptions which respond to stress. Our brain is effected negatively in almost every way when under chronic stress. Our ability to process information is decreased, memory is poorer, and we cannot connect ideas. An adult with high stress scored 50% less on cognitive tests than one with low stress in one study.
Stress hormones called glucocorticoids are created by the adrenal glands near our kidneys. When too much of these stress hormones are introduced to the brain, the negative effects I mentioned occur. These stress hormones also limit new neurons in our brain from forming. The brain’s natural defense to these hormones are the same hormone produced by exercise, BDNF, as I explained in The Psychological Benefits of Exercise.
Chronic stress often leads to depression, especially in a learned helplessness case. Depression results in 800,000 attempted suicides a year.
When children are exposed to parents fighting they are more likely to develop chronic stress. Children don’t feel like they have any control over the situation, which means they feel helpless. Difficulty in regulating emotions, soothing oneself, and lack of focusing attention is developed in these kids. Because of the negative effects of stress, homes with lower stress rates have been linked to kids getting better grades in many studies. The same applies to the workplace and performance from employees.
Medina, John. Brain Rules. 1st ed. Seattle: Pear, 2008. Print.