Prescription drug abuse is taking a medication in any way other than how it was prescribed. That includes taking a higher dose than directed, using someone else’s prescription, or taking a medication specifically to get high. About 14.3 million people aged 12 or older in the United States reported misusing a prescription drug in 2021, making it one of the most widespread substance use problems in the country.
What Counts as Misuse
The line between appropriate use and misuse is more specific than most people realize. You’re misusing a prescription drug if you take it in a larger amount or more often than your prescription says, crush or snort a pill meant to be swallowed, take a medication that was prescribed for someone else (even for a real medical problem like back pain), or continue filling prescriptions from multiple doctors to get more than one provider would give you.
Misuse doesn’t always look like what people picture. A college student borrowing a friend’s Adderall before finals is misusing a prescription drug. So is someone who takes an extra pain pill because one didn’t seem like enough. These behaviors carry real risks even when the intention isn’t to get high.
The Three Drug Classes Most Often Misused
Opioid Pain Relievers
Opioids are the most commonly misused prescription drugs, with roughly 8.7 million people reporting misuse in 2021. This class includes hydrocodone (Vicodin), oxycodone (OxyContin, Percocet), morphine, codeine, and fentanyl. These drugs reduce pain by blocking pain signals in the spinal cord and brain, but they also activate the brain’s reward system, producing feelings of relaxation and euphoria, especially at doses higher than prescribed.
That reward effect is what makes opioids so addictive. Short-term side effects include drowsiness, confusion, nausea, and constipation. The most dangerous risk is slowed breathing. During an overdose, breathing can slow or stop entirely, cutting off oxygen to the brain. This can cause permanent brain damage, coma, or death. In 2021, approximately 16,706 people died from overdoses involving prescription opioids.
Sedatives and Tranquilizers
Central nervous system depressants, including benzodiazepines like Xanax and Valium, are prescribed for anxiety and sleep disorders. About 4.9 million people misused prescription tranquilizers or sedatives in 2021. These drugs work by amplifying the activity of a brain chemical that slows neural firing, producing a calm, drowsy feeling.
Regular use can create severe physical dependence. Withdrawal from benzodiazepines produces symptoms similar to alcohol withdrawal: anxiety, insomnia, tremors, seizures, panic attacks, and in some cases hallucinations or psychosis. Physical symptoms can include headaches, muscle twitches, nausea, and fatigue. Combining these drugs with alcohol or opioids is particularly dangerous because both substances slow breathing, compounding the risk of fatal overdose. In 2021, roughly 12,499 people died from overdoses involving benzodiazepines.
Prescription Stimulants
Stimulants prescribed for ADHD, such as Adderall and Ritalin, were misused by about 3.7 million people in 2021. These medications boost the activity of dopamine and norepinephrine in the brain, increasing focus and energy. At higher doses or when snorted or injected, they can produce euphoria.
Misuse is especially common among students who take unprescribed stimulants hoping to improve academic performance. Ironically, nonmedical use often backfires. It causes anxiety, nervousness, appetite loss, and sleep deprivation, all of which undermine the studying and exam performance the person was trying to improve. More serious risks include dangerously fast heart rate, high blood pressure, and at overdose levels, heart attack, stroke, or seizures.
How Misuse Becomes Addiction
Not everyone who misuses a prescription drug develops an addiction, but misuse is the pathway that leads there. Over time, the brain adapts to the presence of the drug. You develop tolerance, meaning you need higher doses to get the same effect. If you stop taking the drug, withdrawal symptoms push you to use again. At this stage, the person has developed a physical dependence.
Addiction goes further. Clinicians diagnose substance use disorder by looking at a pattern of behaviors grouped into four categories. The first is impaired control: taking more than intended, wanting to cut back but failing, spending large amounts of time obtaining or recovering from the drug, and experiencing intense cravings. The second is social impairment: falling behind at work, school, or home, or continuing to use despite relationship problems. The third is risky use: taking the drug in dangerous situations or despite knowing it’s worsening a health problem. The final category covers the physical markers of tolerance and withdrawal.
A person meeting two or three of these criteria has a mild substance use disorder. Four to five indicates moderate. Six or more is severe. The more criteria someone meets, the more intensive the treatment they typically need.
Who Is Most Vulnerable
Genetics play a significant role. A large-scale study analyzing genomic data from over one million people identified shared genetic markers across different types of addiction, regardless of the specific substance involved. The strongest genetic signals pointed to variations in how the brain regulates dopamine signaling, the system responsible for motivation and reward. People who carry certain combinations of these genetic variants face a higher baseline risk of developing any substance use disorder.
The genetic pattern linked to addiction risk also correlated with higher rates of psychiatric disorders, suicidal behavior, chronic pain, heart disease, and respiratory disease. In children as young as nine or ten who had never used any substance, these genetic markers correlated with parental substance use and behavioral problems, suggesting that vulnerability shows up long before a person ever encounters a drug.
Environment matters too. A family history of substance use, exposure to trauma, untreated mental health conditions like depression or anxiety, and easy access to prescription medications all raise the risk. Mental health disorders and substance use disorders frequently co-occur, and the shared genetic mechanisms between them help explain why.
How Prescription Drug Abuse Is Treated
Treatment typically combines medication with behavioral therapy. For opioid use disorder, medication-assisted treatment pairs counseling with medications that reduce cravings and withdrawal symptoms, making it easier to stop using. The most common approach in outpatient settings uses a combination medication containing buprenorphine and naloxone (often known by the brand name Suboxone), which partially activates the same brain receptors as opioids without producing the same high. Other options include methadone and naltrexone, which blocks opioid receptors entirely.
For benzodiazepine dependence, treatment usually involves a carefully managed taper, gradually reducing the dose over weeks or months to minimize withdrawal symptoms. Stopping abruptly can be medically dangerous. Stimulant use disorder currently has no FDA-approved medication, so treatment relies on behavioral approaches like cognitive behavioral therapy and contingency management, which uses tangible rewards to reinforce drug-free behavior.
Across all three drug classes, addressing co-occurring mental health conditions is critical. Treating one without the other significantly lowers the odds of long-term recovery.
How Monitoring Programs Reduce Risk
Every U.S. state now operates a prescription drug monitoring program, an electronic database that tracks prescriptions for controlled substances. These systems allow prescribers and pharmacists to see whether a patient is receiving overlapping prescriptions from multiple providers or being prescribed risky combinations, such as opioids and benzodiazepines together. Before starting a patient on opioid therapy, clinicians are advised to check the monitoring database to identify potential risks.
On a personal level, the most effective prevention is straightforward: take medications only as prescribed, never share them, store them securely, and dispose of unused pills rather than keeping them in the medicine cabinet. Most people who misuse prescription drugs for the first time get them from a friend, family member, or their own leftover prescriptions.