Trauma and Stress

Stress is an emotional or physical reaction to a challenge or demand, such as school demands, financial problems, or having an illness. A stressor may be a one-time or short-term occurrence, or it can happen repeatedly over a long time.

When a person is under stress, the body reacts by releasing hormones that produce the “fight or flight” response. Heart rate, breathing rate, and blood pressure go up. Occasional stress is a normal coping mechanism. However, long-term stress (also called chronic stress) may contribute to or worsen a range of health problems including digestive disorders, headaches, sleep disorders, and other symptoms. 

Trauma refers to a persistent emotional response to an event, series of events, or circumstances that an individual experiences as harmful or threatening. It can result in heightened stress and other lasting adverse impacts on a person’s functioning and well-being.

A traumatic event is a shocking, scary, or dangerous experience. Experiences like natural disasters (such as hurricanes, earthquakes, and floods), acts of violence (such as assault, abuse, terrorist attacks, and mass shootings), as well as car crashes and other accidents can all be traumatic. Traumatic circumstances can include neglect, loss of a parent or companion, family conflict, racism, and discrimination. In some cases, emotional responses to traumatic events or circumstances continue for a long period of time and interfere with everyday life, a condition known as post-traumatic stress disorder (PTSD). Stress and trauma may contribute to mental health disorders such as depression and anxiety, and to substance use and its progression to substance use disorders.

A person’s experiences over a lifetime are a factor in their brain structure and function. Experiencing abuse or neglect, separation from or loss of a parent or companion, being a victim of violence or bullying, going to war, or experiencing racism or discrimination, among many other events and circumstances, can cause changes in the brain that make a person more sensitive to future events, even daily life stress. 

As a result, a trauma survivor may be more sensitive to and less able to cope with stress in everyday life. Most people will recover from these symptoms, and their reactions will lessen over time. In some cases, these responses continue for a longer period of time and interfere with everyday life, a condition known as post-traumatic stress disorder (PTSD).

Studies show traumatic, extremely stressful experiences like abuse, violence, neglect, or the death of a loved one make a person more vulnerable to developing a substance use disorder.  Someone who has been through trauma or has experienced chronic stress might use substances like drugs and alcohol as a form of self-medication. They may use substances to temporarily cope with the distress they feel or with symptoms of related mental illnesses like post-traumatic stress disorder (PTSD).

Traumatic stress can also cause changes to a person’s brain function and their behavior, making it more likely that substance use will lead to an addiction. This is particularly true in early life: Research shows that experiencing adverse childhood experiences (ACEs) like violence, abuse, neglect, or other early-life stressors is associated with a greater likelihood of developing substance use disorders later in life.

Severe or chronic stress can also affect brain circuits that are involved in reward, motivation, and learning; stress can also increase someone’s craving and decrease their ability to control how they respond to impulses. Addiction affects these same brain processes, which is another reason why researchers think stress increases vulnerability to addiction or relapse, which is when someone who has been abstinent starts to use substances again. Research also shows that having addiction makes stress symptoms worse. 

Not everyone who experiences trauma will develop an addiction. Genetics, environment, family history of addiction, severity of trauma, childhood adversity, and history of past drug use are all factors contributing to a person’s risk of developing a substance use disorder.

Protective factors such as individual traits like optimism and environmental influences like healthy family and peer relationships, as well as targeted prevention interventions, can reduce the risk of developing a substance use disorder. Read more about preventing substance use and substance use disorders.

About 8% of people who have experienced trauma go on to develop PTSD in the course of their lifetime.¹  A person with PTSD has repeated disturbing thoughts and flashbacks of a dangerous, shocking, or scary event. They may often feel afraid, anxious, angry, or ashamed.

Research shows that there is a big overlap between people who have PTSD and those who develop substance use disorders, and many people are diagnosed with both at some point. People with both disorders have more chronic physical health problems, more social problems, and an increased risk of violence or suicide.

A person may also develop other mental health disorders like depression or anxiety after experiencing trauma. These problems are also associated with addiction. In fact, per an analysis of a national survey published in 2017, 3.3% of the US adult population, or 7.7 million adults, had co-occurring disorders during the 12 months before the survey interview.² 

Physical and Sexual Abuse

In one survey of more than 600 people with a substance use disorder, almost half reported suffering physical or sexual abuse, with women reporting much higher rates of both.³  Such abuse presents even greater potential harm for children. People with a history of childhood physical or sexual abuse have, respectively, a 74% and 73% greater risk of developing a substance use disorder in their lifetime than other people.⁴

Violence

People who are the victim of or who witness violence have an increased risk of substance use and misuse. Exposure to interpersonal or intimate partner violence is associated with a risk of substance use and a progression to substance use disorder, particularly for women. Military life is also linked with substance use problems, though military personnel who have had multiple deployments, combat exposure, and combat-related injuries are at greater risk of developing an addiction. Further, many studies show an increase in alcohol, drug use, or smoking following acts of terrorism.

Family Conflict

Parental divorce and conflict, loss of a parent, or poor family relationships contribute to severe, chronic stress that can increase someone’s vulnerability to addiction.

Racism and Systemic Discrimination

Experiencing prejudice and stigma, including racial and ethnic discrimination, can also cause chronic stress, raising the risk of substance use and misuse. Research suggests that people who feel discriminated against because of their gender identity also have a higher risk of substance misuse.

Physical Injury

A serious head injury, particularly in children and adolescents, is associated with a higher risk of addiction. Researchers suspect that a severe injury may disrupt parts of the brain involved with making decisions and controlling impulses.

When someone has a substance use disorder and another mental health disorder, it is usually better to treat them at the same time rather than separately. Some research suggests that this can increase treatment effectiveness for both disorders. For example, in one NIDA-funded study, people who received a treatment called prolonged exposure therapy for PTSD along with treatment for a substance use disorder had more improvement in PTSD symptoms than people who received treatment for addiction alone.⁵  As a best practice, health providers should screen for past trauma when providing care for substance use disorders, given the high rate of people who experience both.⁶

See more information about co-occurring substance use and mental health disorders on the National Institute of Mental Health website.

NIDA supports research to better understand the impact of trauma and chronic stress on the risk of developing a substance use disorder, and on how to prevent that outcome.

For example, NIDA plays a leading role in the Adolescent Brain Cognitive Development® (ABCD) Study, the largest long-term study of brain development and child health ever conducted in the United States. This project will increase our understanding of environmental, social, genetic, and other biological factors that affect brain and cognitive development and that can enhance or disrupt a young person’s life trajectory.

NIDA also supports and funds research, often working with partners at the National Institutes of Health, on effective treatments for substance use disorders in people who have experienced trauma.