Children experience stress as a normal part of growing and learning. Stress is any external stimulus that threatens the balance of the normal equilibrium in the body. It can result from positive as well as negative experiences. The events or experiences that cause stress are known as stressors.

Stress is a normal part of life that can help us learn and grow. When we experience stressors, the body responds by releasing hormones, including adrenaline and cortisol. Cortisol activates the body’s survival instincts, and helps us survive immediate threats. The heart beats faster, the attention span shortens, and judgment may be impaired. More primitive parts of the brain take over as the brain focuses on how to remove the threat. This set of physiological responses is known as the stress response.
There are three different levels of stress that have different effects on the developing brain:
For young children, small amounts of positive stress can teach the developing brain how to manage stress in a supportive environment. But prolonged exposure to toxic stress can have lasting negative effects on brain development.

Levels of Stress

  • Positive stress is a short-term, everyday stress experience which can actually help enhance brain development. These use normal circumstances that help the brain learn how to manage everyday stressors.
  • Tolerable stress results from a more challenging or longer-term stressor, such as moving to a new home, changing child care providers, divorce or remarriage, or the birth of a sibling. The stress is made tolerable because of the presence of at least one supporting, nurturing adult who helps the child manage the stress.
  • Toxic stress results when a person is exposed to severe, chronic stress without the support of a nurturing adult who helps to make the stress tolerable. Toxic stress can do long-term damage to the developing brain.

When the stress response is constantly activated with no way to relieve the stress, the excess cortisol affects the wiring of the limbic system, and the stressful experience is stored as emotional memories. The brain stem, cerebellum and limbic system become overdeveloped and the cerebral cortex may become underdeveloped. Processes such as synapse formation, myelination and pruning may be delayed. The synapses that do develop focus on surviving the stress. A child whose brain is highly aroused is likely to have more difficulty learning and adapting to normal circumstances.