Causes of Addiction
There are many theories about the causes of addiction, the use and abuse of legal and illegal psychoactive substances. Biology, psychology, and social and cultural elements all play a role in the enormously complex causal bouquet that results in addiction, and different theories weight the elements differently. Together they reflect the fact that there is no one path to addiction, and no one factor makes addiction an inevitable outcome. Addiction can’t happen without exposure to agents, but that is hardly the determining factor. Addiction is not a property of the substance ingested or activity engaged in.
Instead, research indicates that it is more related to what else is, or isn’t, going on in a person’s life that makes the sensation a substance induces so attractive. Among the many factors that have been shown to influence the development of an addiction are feelings about oneself, emotional state, quality of family relationships, social ties, community attributes, employment status, stress reactivity and coping skills, physical or emotional pain, personality traits, educational opportunities, compelling goals and progress toward them, opportunities for and access to rewards in life, as well as physiological responses. While no factor predominates, each exerts some degree of influence.
On This Page
- What are the most common causes of addiction?
- What are the most common substances of abuse?
- Are some substances more addictive than others?
- Are there risk factors for addiction?
- Do genes play a role in addiction?
- What biological factors influence addiction?
- What environmental factors influence addiction?
- Does stress play a role in addiction?
- What role does childhood trauma play in addiction?
- Is there a brain malfunction that causes addiction?
- If a family member was addicted, will I become addicted?
- Is there an addictive personality?
- Why do some people become addicted while others do not?
- Can someone get addicted by using a substance once?
- Can drug addiction be prevented?
There are no substances (or activities) that universally or uniformly cause people to become addicted. And the vast majority of people exposed to most substances (or activities) considered addictive do not in fact develop addiction to them. Rather, a very complex array of cultural factors, social factors, and situational factors mingle with psychological factors, biological factors, and even personal values to influence the possibility of addiction.
Many different theories of addiction exist because they weight the role of contributing factors differently. Some current models of addiction emphasize the causative role of individual variations in biology or genes that make a substance or experience feel more or less pleasurable. Many models of addiction highlight the causative role of individual psychological factors, whether personality factors such as impulsiveness or sensation-seeking, or psychopathology such as the negative effects of early trauma. Other models of addiction emphasize the role that social and economic factors play in shaping behavior, such as the strength of family and peer relationships and the presence of absence of educational and employment opportunities.
Around the world and in the U.S., nicotine is the most widely used addictive substance; tobacco causes a reported 40 million deaths worldwide. According to the National Institute of Drug Abuse, smoking kills more than 1,000 Americans every day, and although tobacco use is generally declining in the U.S. its use is increasing among some groups of young people, especially in the form of vaping, or inhaling nicotine vapors.
Alcohol in some form is widely used for pleasurable purposes and is an important part of the social fabric worldwide, today as in ancient times. Nevertheless, according to the National Institute on Alcohol Abuse and Alcoholism, 14.6 million U.S. adults over the age of 18 have alcohol use disorder, marked by uncontrolled drinking. Around the world, 240 million people are reportedly dependent on alcohol; alcohol abuse is most prevalent in Eastern Europe and least prevalent among Asians.
Painkillers including prescription opiates such as oxycodone and fentanyl and the illegal drug heroin account for more than 10 percent of all addictions in the U.S, affecting more than 2.5 million people, according to the American Society of Addiction Medicine.
Cocaine is a stimulant that is often taken intranasally (snorted) or injected intravenously but is considered to have the most potential for addiction because of the fast, intense high when smoked in the form of “crack.” Other stimulants that are subject to abuse are amphetamines, widely prescribed to combat attention deficit hyperactivity disorder and to foster alertness and energy.
Depressive agents such as sedatives and tranquilizers are widely used medically to combat stress, anxiety, and sleep disorders, but NIDA reports that 3.5 to 5 percent of the population uses tranquilizers and sleeping pills nonmedically.
The synthetic stimulant methamphetamine is widely considered one of the most addictive agents. Often inhaled, it directly affects the dopamine and other neurotransmitter systems system to produce an extremely fast and intense—but short-lived—high, with an altered sense of energy and power. Further, by changing the responsiveness of dopamine receptors, methamphetamine blunts the experience of reward from normal sources of pleasure.
Crack cocaine is also considered highly addictive. Cocaine processed so that it can be smoked, it enters the blood stream rapidly and produces a rapid “rush” of a high; the immediate response becomes powerfully reinforcing, driving the motivation to repeat the experience.
There are many risk factors for addiction, from individual factors such as stress tolerance and personality makeup to social factors such as friendships and educational and job opportunities. They interact in dynamic ways unique to each person. But what addiction may come down to for everyone is the emotional and physical appeal of a substance at a particular moment in a person’s life. The effects of drugs are pleasurable and rewarding only in relation to how a person feels emotionally and physically in the context of his or her relationships and social life and other opportunities for development and reward.
Some studies show that genes can account for as much as 50 percent of a person’s risk for addiction, although the degree of genetic influence shifts in importance over time. For example, environmental factors such as family and social relationships are more strongly tied to use of alcohol and nicotine in adolescence than later in life. Nevertheless, there is no single gene for addiction nor even a group of genes.
However, there are a number of personality traits, each of which is partly genetically influenced, that contribute to the risk of addiction. These include impulsiveness, frustration tolerance, and sensitivity to rejection. Impulsivity is thought to play its strongest role in the early stages of addiction, driving the motivation for seeking drugs.
Biology contributes to addiction in ways beyond genes. How the body metabolizes, or breaks down and eliminates, foreign substances such as drugs or alcohol is heavily dependent on the presence of various enzymes, and they may vary significantly between individuals and even between ethnic groups.
For example, research shows that the Japanese have unique variations of certain alcohol-metabolizing enzymes that are not present in other populations, deterring alcohol consumption— and alcoholism—because it quickly gives rise to uncomfortable body sensations. Biological factors such as enzyme profile can influence the amount of alcohol people ingest, the pleasantness of the experience, harmful effects on the body, and the development of disease.
There are many factors that influence addiction beyond genes and biology. One of the most significant is the family milieu and early life experiences. Family interactions, parenting style, and levels of supervision all play a role in development of coping skills and susceptibility to mental health problems. Studies have linked authoritarian or neglectful parenting, family violence, and divorce to increased likelihood of substance use problems later in life. Growing up with strong ties to and a sense of belonging—to a family, to a belief tradition, to a culture—are known to be protective against addiction.
Peers play an enormous role in addiction susceptibility, especially among teens and young adults; most people use drugs for the first time as teenagers. Misuse of prescription drugs, for example, is highest among young adults aged 18 to 25, according to the National Institute of Drug Abuse. Alcohol is the most commonly abused drug among adolescents in the United States. The behavior patterns of friends influence everyone in the group. Further, psychological distress, especially depression and anxiety, has been shown to play an important role in such substance use.
Stress is a risk factor for many kinds of nonadaptive behavior, and addiction is one. Researchers have long linked the effects of chronic stress to alcohol use. Stress relief may enhance the pleasurable effect of any substance. There is some research to support the view that adverse events in childhood and in adulthood change the responsiveness of brain systems. Adverse early life events and cumulative negative events in adulthood—especially those that are both unpredictable and emotionally distressing—alter reactivity of brain structures that govern learning, motivation, the control of distress and control of impulsiveness to increase susceptibility to addiction and to influence the risk of relapse. Stress also increases the risk of mood and anxiety disorders, which are linked to addiction.
Adverse childhood experiences (ACEs) such as trauma, especially combined with an unpredictable and chaotic childhood, pose a risk factor for many kinds of maladaptive behaviors and poor health outcomes. Studies show that having multiple ACEs puts children at risk of poor school performance, unemployment, and high-risk health behaviors including smoking and drug use.
Prolonged stress during childhood dysregulates the normal stress response and, through overproduction of cortisol, is especially harmful to the brain’s hippocampus, impairing memory and learning. Severe or sustained early life adversity shifts the course of brain development and can lastingly impair emotion regulation and cognitive development. What is more, it can sensitize the stress response system so that it overresponds to minimal levels of threat, making people feel easily overwhelmed by life’s normal difficulties. Research shows a strong link between ACEs and opioid drug abuse as well as alcoholism.
The common but mistaken view of addiction as a brain disease suggests that there is some malfunction in the brain that leads to addiction. But that is not the case. Studies show that repeated use of a substance (or an activity), encouraged by a surge in dopamine, creates changes in the wiring of the brain—and those changes are reversible after drug use stops.
Neuroscience research supports the idea that addiction is a habit that becomes deeply entrenched and self-perpetuating, rewiring the circuitry of the brain as it is repeated. The repetition of a highly pleasurable experience—drugs, gambling—alters neurons; they adjust their wiring to become increasingly efficient at the experience. They prune away their capacity to respond to other inputs. It is a form of deeply engraved learning. As drug use stops, engaging in other rewarding activities rewires the brain to find interest and pleasure in non-drug pursuits.
The vast majority of children whose parents abuse alcohol or drugs do not grow up to do the same. However, they are at some increased risk for doing so, and there are a number of reasons why. For one, they are exposed to those substances, and exposure during early adolescence may especially influence substance use.
For another, they may inherit whatever genetic or biological vulnerabilities laid the groundwork for a parental addiction. But they may also be more prone to addiction because they suffer from cognitive, emotional, or behavioral problems known to arise in children as a consequence of growing up in a home marked by substance use; for example, as children they are at increased risk of neglect, abuse, or a poor quality parent-child relationship.
It is a myth that there is some personality factor that is specific for the development of addiction and makes addiction likely. There are a number of personality traits widely shared in the population that contribute to the risk of developing an addiction, usually in indirect ways. For example, people prone to thrill-seeking may be more likely than others to find themselves in situations where drugs are used or to experiment with any number of activities—think: bungee jumping, base-jumping—or substances that provide outsize rewards.
Studies show that those who are high in the trait of neuroticism—they are prone to experiencing negative emotions—are overwhelmed by minor frustrations and interpret ordinary situations as stressful. Neuroticism is linked to a wide array of mental health problems, including anxiety, depression, and eating disorders as well as substance abuse. Neuroticism is also linked to a diminished quality of life, another factor that could increase the allure of substance use.
There is some evidence that natural variation in genetic makeup of the dopamine system may influence who gets addicted. Dopamine is the neurotransmitter activated by rewarding activities as a way of increasing the likelihood of engaging in such activities in the future. Having a relationship, getting a promotion, doing something creative—those are normal ways of stimulating the reward system. Illicit drug use short-circuits that process and directly boosts dopamine levels.
Some people may be more prone to addiction because they feel less pleasure through natural routes, such as from work, friendships, and romance. Their genetic makeup inclines them to develop such personality traits as thrill-seeking. Their craving for risk and novelty takes the fear out of drug use and the huge dopamine boost powerfully reinforces the motivation to seek the reward over and over again.
A person cannot get addicted to a substance without exposure to the substance, but exposure alone does not lead to addiction. Addiction develops only after repeated use of a substance. One use of a substance can produce a pleasurable effect that motivates interest in repeating the experience. But the experience of pleasure is relative; it hinges in part on biology and very much on what else there is going on in a persons life that is meaningful or rewarding.
In its simplest form, drug addiction can be seen as a way of hacking the brain—of finding a shortcut to feelings of emotional reward by bypassing the normal activities that stimulate such sensations and directly manipulating the neurochemicals responsible for them. To a very large degree, brain hacks become appealing when there are restricted opportunities for meaning and for pleasure other than the response to drugs.
Just as recovery from addiction requires focusing on rewarding activities other than drug use, so does prevention. The definition of a meaningful life varies from person to person, but psychology has long identified its components—feelings of self-respect; meaningful relationships that create a sense of belonging; opportunities for growth and development; work that is engaging or rewarding; opportunities for enjoyment and pleasure.