Abundant research in psychology, human development, and other fields has shown that events and circumstances early in peoples’ lives influence future decisions, life events, and life circumstances—or what is called the life course trajectory. People who use drugs typically begin doing so during adolescence or young adulthood, but the ground may be prepared for drug use much earlier, by circumstances and events that affect the child during the first several years of life and even before birth.

Intervening early in childhood can alter the life course trajectory in a positive direction.

The first, overarching principle drawn from research is that intervening early in childhood can alter the life course trajectory of children in a positive direction. Early childhood includes prenatal through age 8, as delineated by the following developmental periods:

• Prenatal Period (conception and birth)
• Infancy and Toddler (birth to 3 years)
• Preschool (ages 3 through 5)
• Transition to School (ages 6 through 8 years)

The “transition to school” period is actually part of the middle childhood and early adolescence period (6 to 13 years), but is addressed separately here because it is a major and significant transition in the child’s development. The middle childhood period is followed by adolescence (ages 13 to 18). The age range for interventions that form the basis for the principles of prevention described in this resource is prenatal through 8 years.

Life course perspectives show risk for drug abuse; How Do We Prevent it?

The period of development discussed above is typically characterized by rapid orderly progressions of normal patterns of physical, cognitive, emotional, and social development. Such development is marked by important transitions between developmental periods and the achievement of successive developmental milestones. How successfully or unsuccessfully a child meets the demands and challenges arising from a given transition, and whether the child meets milestones on an appropriate schedule, most certainly has an affect on his or her future course of development, including an elevated risk for drug abuse or other mental, emotional, or behavioral problems during adolescence.

A number of risk factors can interrupt or interfere with unfolding developmental patterns in all of these periods and, especially, in the transitions between them. Prevention interventions designed specifically for early developmental periods can address these risk factors by building on existing strengths of the child and his or her parents (or other caregivers) and by providing skills (e.g., general parenting skills and specific skills like managing aggressive behavior), problem-solving strategies, and support in areas of the child’s life that are underdeveloped or lacking.

The child’s stages of life, aspects of his social and physical environments, and life events he experiences over time all contribute to his physical, psychological, emotional, and cognitive development.

Life events or transitions represent points during which the individual is in a period of fluidity, sometimes referred to as sensitive, critical, or vulnerable periods. Although vulnerability can occur at various stages throughout the life course, it tends to peak at critical life transitions, which present risks for substance abuse as well as opportunities for intervention. Thus transitions such as pregnancy, birth, or entering preschool or elementary school are prime opportunities to introduce skills, knowledge, and competencies to facilitate development during those transitions. Therefore, interventions are often designed to be implemented around periods of transition.

What are the major influences on a child’s early development?

The changes unfolding throughout a child’s development are influenced by a complex combination of factors. One of them is the genes the child inherits from his or her biological parents. Genetic factors play a substantial role in an individual’s development through the course of life, influencing a person’s abilities, personality, physical health, and vulnerability to risk factors for behavioral problems like substance abuse. But genes are only part of the story.

Another very important factor is the environment, or the contexts into which the child is born and in which the child grows up. The family/home environment is the context that most directly influences the young child’s early development and socialization. This includes quality of parenting and other parenting influences such as genetic factors and family functioning. Also, siblings, if present, can influence a child’s development and adjustment (e.g., internalizing and externalizing behaviors and substance use, as well as positive behaviors). These influences may result from shared environmental experiences and interactions with parenting and other family factors. But conditions at home are also influenced by wider physical, social, economic, and historical realities—such as the family’s socioeconomic status and the affluence and safety of the community in which the family lives. As the child grows older and enters school, these wider environmental contexts influence him or her more directly.

Throughout early childhood, even when the child enters preschool or attends day care, the family remains the most important context for development. Parents play a number of roles in the development of a young child’s social, emotional, and cognitive competence, including establishing the structure and routines for parent-child interactions; maintaining a sensitive, warm, and responsive relationship style; and providing instructional practices and experiences that help the child acquire necessary developmental skills.

When a nurturing, responsive relationship does not exist, elevated levels of stress hormones can impede a child’s healthy brain development. Moreover, when a caregiver cannot provide attention and nurturing because of a history of trauma, chronic stress, and/or mental health problems, the child is more likely to develop behavioral, social, emotional, or cognitive problems. Likewise, impaired judgment related to substance use can reduce a parent’s ability to create a warm, supportive environment for the child. Child abuse and neglect, social isolation due to illness or disability, and lack of constancy in the primary caregiver (as in the case of a child in institutionalized care) are also linked to growth (including brain growth and neuronal connectivity), cognitive, motor, social, and emotional problems. Many of the prevention interventions discussed in this guide are aimed at facilitating constant, nurturing, responsive caregiving to reduce risk and prevent child behavior problems.

Transition to School.

As the child grows older, new transitions and associated challenges occur. A major transition for young children is beginning elementary school. Even children who attended preschool or had been in day care can find the rules for behavior and academic requirements associated with elementary school difficult to adapt to and achieve. Readiness for school is something that occurs over time with experience and practice. Early intervention can help parents and schools assist children through this transition. Once in elementary school, teachers can help children to adjust by providing positive classroom management.

Intervene early in childhood.

Research over the past three decades has identified many factors that can help differentiate individuals who are more likely to abuse drugs from those who are less likely to do so. Risk factors are qualities of a child or his or her environment that can adversely affect the child’s developmental trajectory and put the child at risk for later substance abuse or other behavioral problems. Protective factors are qualities of children and their environments that promote successful coping and adaptation to life situations and change. Protective factors are not simply the absence of risk factors; rather, they may reduce or lessen the negative impact of risk factors.

All children will have some mix of risk and protective factors. An important goal of prevention is to change the balance between these so that the effects of protective factors outweigh those of risk factors. Both risk and protective factors may be internal to the child (such as genetic or personality traits or specific behaviors) or external (that is, arising from the child’s environment or context), or they may come from the interaction between internal and external influences.

Some important early childhood risk factors for later drug use.

Some factors that powerfully influence a child’s risk for later substance abuse and other problems have their strongest effects during specific periods of development. Important examples include:

Prenatal Period

• Maternal smoking and drinking can affect a developing fetus and may result in altered growth and physical development and cognitive impairments in the child.

Infancy and Toddlerhood

• Having a difficult temperament in infancy may set the stage for the child having trouble with self-regulation later, as well as create challenges for the parent-child relationship.
• Insecure attachment during the child’s first year of life can cause a child to be aggressive or withdrawn, fail to master school.
• Uncontrolled aggression when a child is a toddler (2 to 3 years) can lead to problems when he or she enters preschool, such as being rejected by peers, being punished by teachers, and failing academically.

Preschool

• Lack of school readiness skills such as failure to have learned colors, numbers, and counting will put a child at a disadvantage in a classroom environment, setting the stage for poor academic achievement.

Transition to School

• Poor self-regulation can lead to frustration and constant negative attention on the child by peers and teachers at school.
• Lack of classroom structure in the school environment can lead to additional social and behavioral problems in children who have trouble switching from one activity to another.

Other risk factors can affect a child in any developmental period. Some important ones are:

• Stress: All children experience stress at some point, and in fact a certain amount of stress helps young children develop skills for meeting challenges and coping with setbacks that inevitably occur in life. But chronic stressors like family poverty and stress that is intense or prolonged—such as a parent’s mental health problems or a lingering illness—can diminish a child’s ability to cope. These types of stress can even interfere with proper development, including brain development, and aspects of physical health like proper functioning of the immune system. This is particularly true of children who have experienced the extreme stress of maltreatment, such as abuse or neglect, by parents or caregivers. Some children who experience a lot of stress early in life, even during the prenatal period, are more susceptible to the effects of later stressful life circumstances than other people.
• Parental substance use: Parental substance use—including smoking, drinking, illicit drug use, and prescription drug abuse—can affect children both directly and indirectly. Substances used by a mother during pregnancy can cross the placenta and directly expose the fetus to drugs, and substances can pass to a nursing infant through breast milk. When parents smoke in the home, it can also expose children to secondhand smoke, putting them at risk for health and behavioral problems, as well as increasing children’s likelihood of smoking when they grow older. Parental substance use can also impact the family environment by giving rise to family conflict and poor parenting, which could increase risk for child abuse and neglect and involvement with the child welfare system. Poor family functioning can increase the risk for multiple problem behaviors in children and adolescents, including risk for substance use and abuse. Children with a family history of drug abuse also may have increased genetic risk for substance use, often manifested in combination with family or other environmental risk factors. Children can learn about substance use from a very young age, especially if exposed to parental substance use and abuse. However, children are less likely to smoke, drink alcohol, or use other drugs when parents are clear that they do not want their children to do so, even if they use substances themselves.
• Emergent mental illness. Many mental illnesses have symptoms that can emerge during childhood and can increase risk for later drug abuse and related problems. For example, anxiety disorders and impulse-control disorders (such as ADHD) begin their onset prior to 11 years of age, on average, but frequently symptoms may appear in early childhood. Symptoms associated with impulse-control disorders, such as aggressive disruptive behavior, as well as those associated with affective and psychotic disorders all increase the risk of substance use disorders and related problems in adolescence.
  

If not successfully addressed when they initially present themselves, early risk factors and associated negative behaviors can lead to greater risks later in childhood and in adolescence, such as academic failure and social and emotional difficulties, all of which put an individual at increased risk for substance abuse.

https://www.drugabuse.gov/publications/principles-substance-abuse-prevention-early-childhood