We May Be More Vulnerable to Stress in the Evening

A new Japanese study finds that the body’s central nervous system reacts weakly and releases fewer stress hormones in response to stress in the evening compared to the morning.

The findings, published in the journal Neuropsychopharmacology Reports, suggest people may be more vulnerable to stressful events in the evening.
To test this hypothesis, medical physiologist Dr. Yujiro Yamanaka and his colleagues from Hokkaido University recruited 27 young, healthy volunteers with normal work hours and sleep habits to investigate whether the “hypothalamic -pituitary-adrenal” (HPA) axis — which connects the central nervous and endocrine systems of the body — responds differently to acute psychological stress according to the time of day.

Cortisol, the primary stress hormone in humans, is released for several hours when the HPA axis is activated by a stressful event. This provides the body with energy in the face of danger. Cortisol levels are also regulated by a circadian clock in the brain, and are normally high in the morning and low in the evening.
In the study, the researchers first measured the participants’ cortisol levels  to determine a baseline. The volunteers were then divided into two groups: one that was exposed to a stress test in the morning two hours after their normal waking time, and another group that was exposed to a stress test in the evening, ten hours after their normal waking time.
The 15-minute test involved preparing and giving a presentation in front of three trained interviewers and a camera, as well as conducting mental arithmetic. Saliva samples were taken half an hour before the test, immediately after, and at ten-minute intervals for another half hour.
The results show that salivary cortisol levels increased significantly in the volunteers that took the stress test in the morning while no such response was observed in those that took the test in the evening. However, the participants’ heart rates, an indicator of the sympathetic nervous system which immediately responds to stress, did not differ according to when the test was taken.
“The body can respond to the morning stress event by activating the HPA axis and sympathetic nervous system, but it needs to respond to evening stress event by activating the sympathetic nervous system only,” said Yamanaka.
“Our study suggests a possible vulnerability to stress in the evening. However, it is important to take into account each individual’s unique biological clock and the time of day when assessing the response to stressors and preventing them.”

If you experience high levels of stress, we can help. Call us today or make an appointment online. 

Source: Hokkaido University

If not now, when?

You don’t have to go through this alone. Seriously. Let’s get started.

Recent Posts

Featured Testimonials

Chris B.5.0
Read More
Kids are always hard and as a parent it's not always easy to see objectively what is really going on. Jennifer helped me talk through challenges/issues with my oldest son that were running through my head. In the end she provided me a solid perspective to build on and because of that I have been able to manage the situation much better. Easy conversation and very helpful.
Ravenna S.5.0
Read More
Jennifer is such a wonderful and genuine therapist. She is extremely kind and understanding. She comprehends couple and mental health problems precisely. I would definitely recommend her to anyone that is seeking help.
Read More
Jennifer is such a wonderful and genuine therapist. She is extremely kind and understanding. She comprehends couple and mental health problems precisely. I would definitely recommend her to anyone that is seeking help.
Timothy 5.0
Read More
I have been seeing Jennifer De Francisco for about a year, and she has helped me so much with the unhappiness I thought would never go away. Jennifer’s compassion and empathy made me feel safe enough to open up and talk about the uncomfortable feelings I didn’t even know were causing my sadness. With Jennifer’s help, I am now aware of my negative thoughts. Instead of avoiding them, I can work through them. She has helped change my life.
Read More
It was tough when we first started with Jennifer , but through difficult conversations and understanding some of the causes of how closed off we were to each other, we worked through it and are in a good place. The idea that we could break up is the furthest thing from my mind now, and going in to work on our relationship was the best thing to do. One of the things that really helped was that I felt Jennifer really cared that our relationship worked and that we improved things between us. I think that is rare, and always helped me not give up hope.
George S.5.0
Read More
I know people hate to hear this, but relationships take work, especially with kids and stress. I would suggest relationship counseling for any married couple, even if it were just monthly or when things get tough. We continue to see Jennifer after our initial problem because it keeps us on track. Best of luck to all couples looking for help- Jennifer is a wonderful resource.