Stress is a normal part of growing and learning for children. Stress is an interaction between a person and the environment that the person perceives as threatening and can impact the balance of the normal equilibrium in the body.

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.

Types of Stress Responses

There are three types of stress responses that have different effects on the developing brain:

1. A positive stress response is a short-term, everyday stress experience that can actually help enhance brain development. A positive stress response happens when the child encounters simple everyday stressors, such as not getting a cookie right before dinner or having to share a favorite toy. It is characterized by brief increases in heart rate and mild elevations in hormone levels.

2. A tolerable stress response results from a more challenging or longer-term stressor, such as moving to a new home, changing childcare providers, divorce or remarriage, or the birth of a sibling. The stress response is made tolerable because of the presence of at least one supporting, nurturing adult who helps the child manage the stress.

3. A toxic stress response occurs 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 body is constantly flooded with cortisol. This 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.