Summary: Science has long known that emotional distress causes many physical signs. It fires up the sympathetic nervous system, the body’s alarm system. That raises body temperature, pulse and blood pressure. In the short run, these responses can help by starting a fight-or-flight response. But in the long run they do a lot of harm, especially in people with chronic problems like PTSD and panic disorders. In a new study, researchers found the brain circuit behind these physical stress responses. That may one day help find better treatments.
Mental health problems are on the rise, especially ones like PTSD and panic disorders. These cause body signs too: a fast heart, high blood pressure, a stronger stress response and shifts in body heat.
If these physical responses go unchecked, they may change how the body works and raise the risk of many chronic disorders. And it is no secret that emotional disorders like anxiety, PTSD and panic disorders tend to last. Even when drugs treat them, they often come back. Doctors treat both the mental and physical signs of emotional disorders in many ways. For example, they prescribe drugs that calm the brain and steady emotions. But doctors also need to manage the physical signs of emotional disorders and stress.
But most of these treatments fall far short. For example, a drug for a fast heart rate or high blood pressure helps. But it does not treat the root cause. So we need to understand better how emotional disorders cause physical signs. Emotional responses start deep inside the brain. From there, circuits connect them to the brain centers that control body functions.
Which brain circuit causes physical responses to stress?
In the study from Nagoya University in Japan, researchers found that stress responses start deep in the limbic system (the area of the brain that controls emotions). From there, the signal moves to the dorsal peduncular cortex and the dorsal tenia tecta (DP/DTT). Then it goes on to the hypothalamus, which sets off the body’s responses. The hypothalamus is like a junction box, linking deep brain centers to the areas that run the sympathetic nervous system (the body’s alarm system) and the motor system.
Emotional responses seem to mainly fire up the sympathetic nervous system. That speeds up body functions, raising blood pressure, body temperature and heart rate. The short-term physical responses are the same each time, but the long-term ones are not. In the short run, these responses help mammals deal with threats by starting the fight-or-flight response.
The trouble is that many people now live with long-term anxiety. So the circuit that drives the body’s stress response stays on for days or even months. This nonstop firing is why stress problems, anxiety and panic attacks are rising around the world.
But as the researchers noted, we can only treat or prevent these conditions if we understand how they work. The researchers ran this experiment in lab mice to map the whole circuit. To confirm that this pathway plays a role in physical responses, they impaired the links from the DP/DTT to the hypothalamus. The physical stress responses became much weaker.
So the study showed that the DP/DTT sends the signal on to the hypothalamus. It also showed that this path plays a key role in how the body reacts to stress and anxiety. This is one of the first studies to show what this path does in stress.
Researchers from Nagoya University say each find like this is a step toward the “mind-body connection.” In the end, it could help doctors treat PTSD and panic disorders. It could also help stop the long-term illness that years of stress can cause.
Frequently asked questions
How does emotional stress cause physical symptoms?
Emotional stress turns on the sympathetic nervous system, the body’s alarm system. The signal starts deep in the limbic system, the brain’s feeling center. It moves to an area called the DP/DTT and then to the hypothalamus. The hypothalamus works like a junction box. It drives the body’s response: a faster heart, higher blood pressure and a rise in body heat.
What are the physical effects of emotional stress?
The classic signs are a faster heart rate, higher blood pressure, a stronger stress response and changes in body temperature. PTSD, anxiety and panic disorder all produce them. In the short run these signs power the fight-or-flight response. Left unchecked, they can change how the body works and raise the risk of chronic disorders.
Why is long-term stress harmful to the body?
The fight-or-flight response is built for short bursts. In chronic anxiety, the brain circuit that controls physical stress responses stays switched on for days or even months. That nonstop firing is why stress-related disorders, anxiety and panic attacks are rising worldwide. It also pushes the body toward chronic disease.
Can PTSD and panic disorder be treated at the physical level?
Current treatments help but fall short. Doctors prescribe drugs that calm the brain and steady emotions, plus drugs that lower heart rate and blood pressure. But those do not fix the root cause. The DP/DTT-to-hypothalamus pathway, found in lab animals, gives researchers a new target for treating PTSD and panic disorder.
Dr. Gurpreet Singh Padda, MD, MBA, MHP
