Chronic Stress is Harmful, But Short-Term Stress Can Help

Did you ever embark on a frenzied all-nighter to cram for a test, then enjoy a rush of accomplishment after acing it the next day? At the end of the day, all of that overnight stress seemed to be worth it, and it may have even helped spur you on to get the work done.

On the other hand, stress over a longer period of time, say, if a loved one falls ill or if financial hardship sets in, is an entirely different beast. Long-term stress can cause you to suffer from insomnia, have trouble focusing, or become depressed or even seriously ill.

The more researchers learn about stress, the more it seems there are two distinct ways we experience it: acute, or short-lived stress, and chronic, or long-term stress.

Most recently, new research published in the journal eLife found that acute stress may actually cause new cells to develop in our brains, improving our future mental performance. This would mean that periods of short-lived stress help us adapt to, and better negotiate, our environments.

To arrive at these findings, researchers at the University of California, Berkeley focused on the effects of stress on the brain’s hippocampus, which plays a critical role in memory. Past research has shown that chronic stress suppresses development of new neurons in this area of the brain, taking a toll on memory. But how acute stress affects this process has not previously been as clear.

To find out, the researchers subjected rats to acute stress by immobilizing them for a few hours. The rats’ stress hormones shot up. After the experiment, the researchers found that the stress seemed to double the amount of new brain cells in the hippocampus compared to control animals. The rats that were stressed out also performed better on a memory test two weeks after their stressful experiment, but not two days after. Using cell labeling, the researchers confirmed that the nerve cells involved in learning the new tricks two weeks later were the same new ones that developed following the stressful event.

While rats and humans are very different animals, the findings do hint at the possibility that acute stress may in fact make us stronger. Other studies confirm the benefits of acute stress, too. For example, NBC News writes:

Moderate amounts of stress — the kind of short-term buzz we get from a sudden burst of hormones — can help people perform tasks more efficiently and can improve memory. Good stress is the type of emotional challenge where a person feels in control and provides some sense of accomplishment. It can improve heart function and make the body resistant to infection, experts say. Far from being something we need to eliminate from our lives, good stress stimulates us.

Some believe short-term boosts of it can strengthen the immune system and protect against some diseases of aging like Alzheimer’s by keeping the brain cells working at peak capacity. People who experience moderate levels of stress before surgery have a better recovery than those with high or low levels, another study showed. Recently, a study suggested that stress could help prevent breast cancer because it suppresses the production of estrogen. And earlier this year, research out of Johns Hopkins found that children of mothers who had higher levels of the stress hormone cortisol during pregnancy were developmentally ahead of those of women with lower levels.

 On the other hand, chronic stress is indeed a scary thing. Huffpo breaks down some of the most serious implications of long-term stress: 

• Causes cancer in animals
• Shrinks the brain
• Prematurely ages kids
• Could impact your future children’s genes
• Raises the risk of stroke
• Increases risk of chronic diseases like heart problems and arthritis 

How we handle stress, however, largely seems to be out of our control. We can do yoga, go to therapy and workout, but external factors will probably get the best of us now and then. The Daily Beast sums this problem up:

Psychologists have known for years that one of the biggest factors in how we process stressful events is how much control we have over our lives. As a rule, if we feel we’re in control, we cope. If we don’t, we collapse. And no amount of meditation or reframing our thinking can change certain facts of our lives. With the market languishing and jobs hemorrhaging and the world going to hell, too many of us probably feel like that rat in the second wheel: it’s hard to convince ourselves we’re in control of anything.

More from Smithsonian.com:

Simply Smiling Can Actually Reduce Stress
New Gene Provides Link Between Stress and Depression  

Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.