“Why did this happen to my kid? We gave him everything.” That question, or some version of it, comes up constantly from families trying to understand how someone they love ended up addicted. The honest answer is rarely simple, and it’s rarely about willpower or a single bad decision.
Researchers have spent decades studying why some people develop a substance use disorder, and others don’t; what they’ve found points to five main factors that tend to show up again and again: genetics, chronic stress, trauma and adverse childhood experiences, mental health, and environment. Most people who become addicted have more than one of these at play, not just one.
Genetics Load the Dice
Genetics accounts for roughly 40% to 60% of a person’s vulnerability to addiction, based on research from the National Institute on Drug Abuse.1 That vulnerability comes from gene variations passed down from parents, and it varies by substance. Hallucinogens have the lowest heritability among addictive substances, while cocaine has one of the highest.2
That doesn’t mean genetics decide the outcome. A person with a strong genetic predisposition can still avoid addiction with a stable environment and healthy coping skills, and someone with no family history at all can still develop one. Genetics loads the dice; it doesn’t roll them.
Chronic Stress Wears Down Coping Ability
Chronic stress is different from a bad week. It’s stress that doesn’t let up: financial strain, a toxic workplace, a struggling marriage, an unaddressed health condition, or ongoing loss. When stress builds like that without a real outlet, substances can start to feel like the only thing that brings relief.
The relief is temporary and often worsens the underlying problem. Alcohol or drugs may dull the immediate discomfort, but they also wear down a person’s actual ability to cope with stress over time, which means the next stressful event hits even harder. Practices like deep breathing, exercise, and structured routines are consistently more effective for managing chronic stress long-term, even though they take more effort upfront than reaching for a drink.
Trauma and Adverse Childhood Experiences Leave a Mark
Early trauma is one of the strongest predictors of later substance use. People who’ve lived through psychologically traumatic events often turn to substances as a way to manage the aftermath, especially when that trauma hasn’t been processed and shows up as PTSD or chronic anxiety.
Teens who experienced abuse are roughly three times more likely to report substance use than teens without that history. In one study of adolescents in substance use treatment, more than 70% had a documented trauma history.3 Adverse Childhood Experiences, or ACEs, are potentially traumatic events that happen before age 18, things like abuse, neglect, domestic violence in the home, or a parent’s incarceration or mental illness. People with two or more ACEs are about four times more likely to develop a substance use problem, and people with five or more are seven to ten times more likely to become addicted to illegal drugs and three times more likely to misuse prescription pain medication.3,4
For anyone whose substance use is tied to early trauma, learning more about the connection between ACEs and addictioncan be a useful next step.
Mental Health and Addiction Often Travel Together
Mental health conditions and substance use disorders overlap constantly. According to the National Alliance on Mental Illness, roughly one-third of people living with mental illness also struggle with drug or alcohol use, and 37% of people who misuse alcohol and 53% of people who misuse drugs also have at least one mental illness.5
Often, this starts as an attempt to self-medicate. Someone with untreated anxiety or depression finds that a substance dulls the symptoms, at least temporarily. But substance use tends to intensify the underlying mental health condition over time, and can even generate new symptoms that weren’t there before. When both conditions exist together, professionals call this a co-occurring disorder or dual diagnosis, and treating them separately rarely works as well as addressing them together in an integrated program.
Environment Shapes Access and Exposure
Where and how someone grows up plays a real role in whether substance use ever becomes a possibility in the first place. Poverty, family dysfunction, struggles at school, and pressure from peers or community all factor in.
Growing up with a family member who misuses substances raises a child’s own risk of future use. In adolescence, peer influence carries enormous weight, and easy access to substances at home or in the community lowers the barrier to using them in the first place.6 None of this determines an outcome on its own, but it shapes the conditions someone is working against.
Frequently Asked Questions
Is addiction mostly genetic, or mostly environmental?
Neither factor works alone. Genetics account for a significant share of a person’s vulnerability, but environment, stress, trauma, and mental health all interact with that underlying risk to shape whether addiction actually develops.
Can someone become addicted without any of these risk factors?
Yes, though it’s less common. These five factors describe the most consistent patterns researchers have found, not an exhaustive list, and addiction can still develop through pathways that don’t fit neatly into any single category.
Does having a mental health condition mean someone will develop an addiction?
No. Having a mental health condition increases risk, but it doesn’t make addiction inevitable, especially when the condition is being actively treated.
What can families do if several of these factors apply to someone they love?
A professional evaluation is the best place to start. Understanding which factors matter most for a specific person helps shape a treatment plan that addresses the root causes, not just the substance use itself.
Getting Help
The reasons behind a drug or alcohol addiction are almost always layered, not singular, which is exactly why effective treatment needs to look at the whole picture rather than just the substance itself.
At Spring Gardens Recovery, treatment plans are built around each person’s specific history, whether that includes genetic risk, chronic stress, trauma, a co-occurring mental health condition, or environmental factors. Hence, the care actually fits the reasons behind the addiction. Contact our team or call 352-480-0669 to learn more about our treatment programs.