Stress in early childhood

Early childhood is a critical period in a child's life that includes ages from conception to five years old.^[1][2] Psychological stress is an inevitable part of life. Human beings can experience stress from an early age. Although stress is a factor for the average human being, it can be a positive or negative molding aspect in a young child's life.^[3]

A certain amount of stress is normal and necessary for survival. A few stressors can be manageable for young children; stress can be beneficial by helping children develop skills needed to adapt to a new set of circumstances and deal with dangerous and intimidating situations. Some experts have theorized that there is a point where prolonged or excessive stress becomes harmful and can lead to serious health effects.^[4] When stress builds up in early childhood, neurobiological factors are affected.^[1] In turn, levels of the stress hormone cortisol exceed normal ranges.^[1] This theory however is based on animal studies and cross-sectional studies in humans, and the proposed impacts on brain centers have not been found in a landmark twin study^[5] and studies where neurobiological factors were measured in humans prior to stress or trauma exposure.^[6][7]

Researchers have proposed three distinct types of responses to stress in young children: positive, tolerable, and toxic.^[8] These labels are based on theorized differences in lasting physiological changes occurring as a result of the intensity and duration of the stress response.^[9]

Stress is caused by internal or external influences that disrupt an individual's normal state of well-being.^[10] These influences are capable of affecting health by causing emotional distress and leading to a variety of physiological changes.^[4] Internal stressors include physiological conditions such as hunger, pain, illness or fatigue. Other internal sources of stress consist of shyness in a child, emotions, gender, age and intellectual capacity.^[3] Childhood trauma has lifelong impact.

Exposure to adverse childhood experiences can include separation from family, home violence, racial/ethnic disparities, income disparities, neighborhood violence, mental illness or substance use disorder of caregiver, physical/sexual abuse, neglect, divorce, a new home or school, illness and hospitalization, death of a loved one, poverty, natural disasters, and adults’ negative discipline techniques (e.g. spanking).^[3] Additional external stressors include prenatal drug exposure, such as maternal methamphetamine use, other maternal and paternal substance abuse, maternal depression, posttraumatic stress and psychosis.^[3][11][12]