Effects of Stress on Brain Development
Prolonged stress in young children can slow brain development. Prolonged exposure to cortisol released during the stress response can cause long-term damage to the developing brain. When children regularly experience chaos or stress, their brains become wired to react quickly to threatening, stressful experiences. Even after the threat is removed, the brain may continue to respond as if the stress is still present. Children whose brains have been wired by prolonged stress may overreact in some situations. Prolonged stress may lead to learning difficulties, delays in brain development, and later difficulties coping with life’s demands.
The stress response begins in the brain. When a person confronts a stressor, the eyes or ears (or both) send the information to the amygdala, an area of the brain that contributes to emotional processing. The amygdala interprets images and sounds. When danger is perceived, it sends a distress signal to the hypothalamus. The hypothalamus can be compared to a command center. After the amygdala sends a distress signal, the hypothalamus activates the sympathetic nervous system by sending signals through the autonomic nerves to the adrenal glands. These glands respond by pumping the hormone epinephrine (also known as adrenaline) into the bloodstream.
Young children whose frontal lobes are not fully developed are unable to respond rationally to stress. In order to handle stress and return to calm, young children need caregivers to comfort and reassure them that they are safe. If their environment is constantly threatening, or children do not have a reliable caregiver, they will rely on the brain stem and limbic system to handle stress. The brain stem will become over-developed, and areas responsible for emotional control and rational decision-making may not develop fully. Warning signs of an imbalance in brain development due to prolonged stress may include anxiety, impulsiveness, hyperactivity, poor impulse control, lack of empathy, and poor problem-solving skills.