How does stress affect the brain?

Stress is a normal process we use to cope with physical and emotional threats and challenges. The way we perceive stress factors determines whether stress is experienced as a panic or a challenge. While normal stress protects the body in times of threat, prolonged stress may potentially damage the body, including the brain.

As science gains greater insight into the consequences of stress on the brain, the picture that emerges is not a pretty one. A chronic overreaction to stress overloads the brain with powerful hormones that are intended only for short-term duty in emergency situations. Their cumulative effect damages and kills brain cells.

When a stressful situation occurs, the body reacts with an outpouring of the hormones that increase heart rate and respiration, send more blood to skeletal muscles, stimulate the immune system, and turn sugar and fat into energy. This is done to prepare the body for either a fight or flight. And, you have plenty of energy to do either, because adrenaline causes a rapid release of glucose and fatty acids into your bloodstream. Also, your senses become keener, your memory becomes sharper, and you are less sensitive to pain.

Other hormones shut down functions unnecessary during the emergency. Growth, reproduction, and the immune system all go on hold. Blood flow to the skin is reduced. That's why chronic stress leads to sexual dysfunction, increases your chances of getting sick, and often manifests as skin ailments.

In most cases, the response occurs for a limited time to aid the individual in dealing with a specific stress situation. Then the body returns to a normal, non-stressed state.

Sometimes, however, the presence of sustained stress--abuse, combat, perceived unrealistic pressures, illness, anger-producing situations--can have markedly damaging effects on the body and the brain. Robert Sapolsky at Stanford University, and others, have investigated stress and health and report that a prolonged flood of stress hormones can actually cause shrinking in certain brain areas, particularly in the hippocampus.

A major role of the hippocampus has to do with memory. It is not unusual for people undergoing prolonged stress to report forgetfulness and difficulty learning. A hopeful discovery is that certain portions of the hippocampus can recover once the stress response is reversed.

Since catastrophes, life changes, conflicts, and the myriad things that produce a stress reaction are a part of most people's lives, it is how we learn to interpret and control these stressful situations that is crucial.