Risk factors for substance use and substance use disorders can include a person’s genes, other individual characteristics, and aspects of their social environment, and the impact of these factors can change at different stages of a person’s life. 1 Generally, the more risk factors a person has—such as early-life trauma, chronic stress, a family history of addiction, or peers who use drugs—the greater the chances that they will use substances and develop a substance use disorder. 2,3
But even in the presence of multiple risk factors, substance use and substance use disorders are not inevitable. Other factors can help protect someone from using substances and developing a substance use disorder. Protective factors include individual traits like optimism and environmental influences like healthy family and peer relationships and financial stability.4
It is important to note that many risk and protective factors are not a result of choices an individual person makes, but rather are a facet of their inherited genetics, family, life circ*mstances, and other aspects of their biology and environment. Better understanding these factors is critical to developing prevention strategies that lessen the impact of risk factors and bolster or introduce new protective factors. NIDA funds research to identify risk and protective factors and seek ways to prevent substance misuse and substance use disorders even when multiple risk factors are present. This includes the Adolescent Brain Cognitive Development℠ Study (ABCD Study®) and the HEALthy Brain and Child Development (HBCD) Study, which will inform our understanding of healthy development—including brain and cognitive development, and how drugs and other exposures affect it—and the HEAL Prevention Cooperative, which is supporting research to prevent opioid misuse and opioid use disorder among vulnerable adolescents and young adults.
Examples of factors that may influence a person’s likelihood of drug use, misuse, or of developing a substance use disorder include:
Individual Factors
- Age at substance use initiation: Drug use at a young age can influence brain development and behavior in ways that increase the likelihood of going on to use other drugs and developing a substance use disorder.5 Consequently, people who start to use substances as children and young adolescents are more likely to develop a substance use disorder than are those who first use substances in late adolescence or young adulthood.6,7,8 For this reason, most prevention programs focus on preventing or delaying substance use in youth. Read more about prevention for young people.
- Genetics: Inherited biological factors can play a significant role in a person’s likelihood of using substances and of developing a substance use disorder.2,10
- Other mental health problems: People with other mental illnesses like depression, anxiety, PTSD, and many other psychiatric conditions are also more likely to use substances and to develop substance use disorders.4,11,12
- Biological sex: Factors related to biological sex—such as different brain structure and function, tissue composition, endocrine, and metabolic functions in males and females—can influence how a person responds to drugs.13 For example, women use drugs less frequently and in smaller amounts than men, but they can experience the effects more strongly, and substance use in women tends to develop into addiction more quickly than in men.14,15
- Personality: Individual characteristics such as risk-taking, sensation-seeking, aggression, or heightened responses to chronic stress can influence the likelihood of using substances and developing a substance use disorder.16,17,18
- Specific types and patterns of drug use: Use of certain drugs such as opioids, nicotine, and methamphetamine is associated with a higher likelihood of developing a substance use disorder than is use of other drugs like psychedelics.19,20 Similarly, injection drug use is more strongly associated with developing a substance use disorder, as more drug is delivered more rapidly to the brain than via other routes of administration. 21
Family Factors
- Family relationships: Research shows that growing up in a supportive, stable family environment versus one associated with adverse childhood experiences (ACEs) like trauma, abuse and neglect can impact a person’s likelihood of problem drug use and of developing substance use disorders later in life.22,23 A higher level of parental involvement and young people’s perceptions that parents are aware of their activities have also been found to be protective.24,25
- Parental substance use and attitudes: Whether parents use drugs or alcohol and their level of permissiveness or acceptance of substance use influence whether a child or adolescent is likely to use substances.26,26
Community Factors
- School: Studies show certain aspects of a school environment—such as how often other students use drugs and how connected students feel to their classmates—can influence whether students use or avoid substances. 4 ,27
- Peers: Whether an individual’s peers use drugs or disapprove of substance use is a major influence on whether that individual will use substances, particularly during youth. 4 ,27
- Neighborhood: Research shows that living in a neighborhood with high levels of poverty or violence is associated with a higher likelihood of using substances.25,27,28 Positive community relationships and environments have been associated with less substance use and less progression from substance use to substance use disorders. 29
Structural Factors
- Social: Stigma and discrimination on the basis of race, ethnicity, gender, or other factors can cause chronic stress that makes someone more vulnerable to substance use and to developing substance use disorders.30
- Economic: Growing up in a household or neighborhood with lower resources can affect children’s brain development in ways that may make them more vulnerable to future substance use disorders.31 Housing insecurity and limited access to education and employment are also associated with substance use disorders.32
- Laws and culture: Access to substances,27as well as the laws, policies, culture, norms, and attitudes surrounding their use in a society, can influence whether an individual uses substances and experiences related health problems including substance use disorders.4
