Many people searching for the signs of drug addiction are not trying to make a diagnosis. They want to know whether what they are seeing is real. The honest answer is that no single sign settles it. Pupils change size for a dozen reasons. Plenty of people have a bad stretch with no drug use at all. What clinicians look at instead is a pattern of symptoms.
They measure that pattern against eleven criteria, over twelve months. This guide explains the criteria in plain words. It walks through the physical, behavioral, and emotional warning signs that show up first.
Our guide also shows where the line sits between a habit, a dependence, and a disorder. Our drug addiction treatment program at New Wave Recovery on the North Shore works with family members who arrive at this exact question.
What Counts as Drug Addiction
Substance use disorder is the clinical diagnosis for a problematic pattern of substance use. Addiction often refers to its more severe forms. Clinicians assess criteria from the Diagnostic and Statistical Manual of Mental Disorders. published by the American Psychiatric Association. You do not have to hit rock bottom to meet them. You do not have to lose a job or use every day either.
The Eleven Criteria
Cleveland Clinic lists the eleven signs of addiction:
- 1. Taking the drug in larger amounts, or for longer, than intended.
- 2. Intense urges or a strong desire to use it.
- 3. Trying to cut down and not managing it.
- 4. Spending a lot of time getting the drug, using it, or recovering from it.
- 5. Trouble meeting work responsibilities, or duties at school or home.
- 6. Carrying on despite strained relationships.
- 7. Giving up social, occupational, or recreational activities.
- 8. Using again and again in situations where it is dangerous.
- 9. Carrying on despite a physical or psychological problem the drug is likely causing.
- 10. Building tolerance, so more is needed for the same effect.
- 11. Withdrawal symptoms, or taking the substance to relieve or avoid withdrawal [1].
At least two applicable criteria within twelve months, with clinically significant impairment or distress, can meet the diagnostic threshold. Tolerance and withdrawal during appropriate medical treatment do not by themselves establish a disorder; substance-specific diagnostic rules apply.
Mild, Moderate, or Severe
Severity is counted the same way. Two or three criteria is a mild disorder. Four or five is moderate.
Six or more criteria indicate a severe disorder [1]. The count describes severity, but the level of care also depends on withdrawal risk, other health conditions, safety, support, and the person’s circumstances.
A structured program may fit some people, while others can receive less intensive care. Visible changes can prompt a conversation, but they cannot determine the diagnosis or level of care.
That is why posts like the one on dilated pupils and drugs get searched so often. Tolerance and withdrawal can involve physical changes, but pupil size alone is not one of the diagnostic criteria.
Physical Signs of Drug Addiction
Physical symptoms are still worth knowing. They are the ones that prompt the first conversation. They split into what shows while the drug is working, and what builds up over weeks of drug use.
While the Drug Is Active
Different substances do almost opposite things. The common signs vary depending on what the person takes. Stimulants bring dilated pupils, a racing pulse, fast talk, and no interest in food or sleep.
Opioids may cause small pupils, drowsiness, itching, and dangerously slow breathing. Cannabis can cause bloodshot eyes and slower reactions. Alcohol and other sedating drugs may cause slurred speech and poor coordination. These signs also have other possible causes.
Sweating, tremor, irritability, and fatigue can occur with some substances or during withdrawal. They can also reflect medical conditions unrelated to substance use. Our chapter on the signs of cocaine use covers the stimulant version, including the crash that follows.
What Builds Up Over Weeks
Unplanned weight change, disrupted sleep, or declining self-care may develop over time. These are reasons to ask about health and seek assessment, rather than reliable proof of addiction.
Personal hygiene and appearance slip in someone who used to care. Frequent minor illnesses, dental problems, and unexplained marks or bruises turn up. Nosebleeds are common in people who are snorting drugs.
Repeated flu-like symptoms can sometimes reflect withdrawal, but infection and other illnesses also need consideration. Pain pills have their own risks, which the chapter on what makes Percocet different from plain oxycodone sets out.
Behavioral Signs of Drug Addiction
Changes in how a person uses a substance and the consequences of that use can be more informative than appearance. There is no fixed order in which behavioral and physical changes develop.
Secrecy and the Shape of the Day
New secrecy, unexplained absences, or guarded answers may prompt concern. Locked doors or a private phone are not diagnostic signs on their own.
Answers about where the afternoon went turn vague. An ordinary question draws a flash of anger. Then more and more of the day goes to the drug: getting it, using it, and recovering from it.
That is one of the eleven criteria, almost word for word. Prescription medicines follow the same shape. Refills run out early, and requests arrive before the date.
Money, Work, and the People Around Them
Unexplained spending, repeated borrowing, or financial strain can accompany problematic substance use. They can also have other explanations.
Some people do steal money or valuables once a supply runs short. Work responsibilities slide, shifts get missed, and co-workers start covering. Old friendships fade, and a new group appears that no family member has met.
A sudden disinterest in old hobbies is one of the most telling behavioral changes of all. High-risk behavior tends to rise too, from driving while impaired to unprotected sex. Legal trouble sometimes follows.
Several changes together warrant a calm conversation and assessment. Even a cluster of signs does not prove substance use or addiction.
Mood and Psychological Signs
Family members may notice mood changes before anything else. Irritability, low mood, or anxiety can accompany substance use, withdrawal, or an unrelated mental health problem.
Repeated substance use can affect reward and stress systems. Mood changes may track use or withdrawal, but a clinician should assess other causes rather than assuming the drug explains every change.
The link runs both ways. Sometimes the mental health condition came first, and the drug was an attempt to manage it. Sometimes heavy use caused the mood problem, and the damage to overall well-being with it.
When a substance use disorder and another mental health condition occur together, coordinated treatment is appropriate. Prescribed stimulants such as Adderall can also affect mood and sleep, including when taken correctly.
The chapter on how prescription stimulant dependence develops works through how to tell a prescribed rhythm from a problem.
Why Signs Alone Are Not a Diagnosis
This distinction is what keeps families from panicking and from dismissing what they see.
Dependence Is Not the Same as Addiction
Physical dependence means the body has adapted. Stopping then brings withdrawal symptoms. That is expected, and it is not a moral failing.
It happens to people taking medicine exactly as prescribed. Addiction is different. It is the loss of control the eleven criteria describe. A person can be physically dependent on a medication without having an addiction. Someone else can meet substance use disorder criteria without prominent tolerance or withdrawal.
The chapter on gabapentin’s misuse and withdrawal risks shows how wide that gap can be.
Patterns Matter More Than Incidents
No single sign confirms anything. Several symptoms above also mimic other health conditions. Thyroid problems, depression, sleep disorders, and ordinary grief all overlap.
A diagnosis depends on the applicable criteria and impairment or distress within a twelve-month period. Problems can emerge quickly; families do not need to wait months or see harm in every area of life before seeking help.
Repeated problems alongside missed duties or other harms warrant assessment. They still require context rather than an assumption about their cause.
What Raises the Risk
Addiction is not spread evenly. Several risk factors shape who develops one. Cleveland Clinic lists a mental health condition and a blood relative with a substance use disorder.
A history of adverse childhood experiences and easy access to drugs can increase risk. NIDA estimates that genetic factors account for roughly 40 to 60 percent of vulnerability [2]. This describes variation across populations, not a precise genetic share of one person’s risk.
Environment, early exposure, and the substance itself also influence risk. No single factor determines whether someone develops a disorder, and there is no fixed timeline.
Substance use disorders can develop at many ages. A natural or legal label does not establish safety or eliminate addiction risk.
The chapter on kratom addiction covers that in detail.
When Signs Become an Emergency
Some signs call for immediate emergency care. Suspected overdose is life-threatening and requires 911, regardless of whether the person has a diagnosed substance use disorder.
MedlinePlus describes an opioid overdose as very small pupils and no response, with breathing that slows or stops. There may be choking or gurgling sounds.
The limbs go limp, and the lips and fingertips turn blue or grey [3]. Give naloxone if you have it.
Call 911. Repeat naloxone after two to three minutes if normal breathing has not returned, following the product instructions. Follow the dispatcher’s CPR instructions if the person is not breathing normally. If unconscious but breathing normally, place them on their side and stay. Naloxone is available without a prescription.
Massachusetts’ Good Samaritan law provides limited protections for people who seek emergency help in good faith; it does not cover every offense [4]. In 2024, among opioid-involved overdose decedents who received a toxicology screen, fentanyl was detected in 89 percent and cocaine in 56 percent [5]. These findings do not establish how the drugs were taken.
A stimulant in this state can carry an opioid risk the person never chose. Anyone around opioid use should know the signs of opioid addiction and keep naloxone at home. If suicide comes up at any point, call or text 988.
What to Do When You Recognize the Signs
Recognizing a pattern is the hard part. What comes next is simpler than most families expect.
How to Raise It
Pick a moment when the person is neither high nor withdrawing. A weekday evening usually works. Describe what you have seen rather than what you have concluded: the missed shifts, the money, the sleep.
Empathy gets further than confrontation. An accusation almost always ends the conversation early. Set the boundaries you mean to keep.
That protects you, and it stops the small allowances that let a pattern continue. Expect denial the first time, and do not treat it as the final answer.
What Treatment Looks Like
An initial confidential call can explain options. A comprehensive assessment may take place in person, by telehealth, or over more than one visit with a qualified clinician.
A clinician should assess withdrawal risk from opioids, alcohol, benzodiazepines, and other drugs. Some people need medically managed withdrawal; others can begin ongoing treatment without inpatient detox. New Wave does not provide detox, and the drug and alcohol detox page explains referrals.
After that, treatment runs at the day treatment level. That is the Massachusetts term for a partial hospitalization program. It can also run as an intensive outpatient program, or as weekly therapy.
The level of care is matched to a full assessment, not the criterion count alone. Continuing care and support groups can help after a program, although the plan should fit the individual.
Among people who needed substance use treatment in 2025, about 16 percent received it [6]. Cost, access, and other barriers can matter. Insurance coverage, networks, and out-of-pocket costs vary, so ask the program and insurer about the specific plan.
Starting earlier improves those odds. Needing more than one attempt is ordinary.
Frequently Asked Questions About the Signs of Drug Addiction
What Are the First Signs of Drug Addiction?
Changes may include missed responsibilities, unexplained spending, withdrawal from activities, or difficulty controlling use. No single change always comes first. Physical symptoms may include weight or sleep changes, but they are nonspecific. Tolerance is one possible criterion, not a necessary or universally earliest sign.
What Behavior Changes Point to Drug Addiction?
Watch for more of the day going to the drug, locked doors, and a phone kept face down. Ordinary questions draw defensiveness. Add missed shifts, financial problems, dropped hobbies, a new peer group, and sometimes legal trouble.u003cbru003eu003cbru003eSeveral changes together justify a conversation and assessment, but can still have explanations other than addiction.
Can Someone Be Addicted and Still Seem Fine?
Yes. Someone can keep working and maintain their appearance while experiencing a substance use disorder. Visible disruption does not reliably show which criteria are present. Severity is counted by criteria met, not by visible damage.
How Do I Know if I Am Overreacting?
Look for changes from the person’s baseline and ask about context. Do not wait for months of visible deterioration if safety, substance use, or mental health is already a concern. A confidential clinical assessment can clarify the concern and discuss options without committing someone to a particular program.
What Is the First Step Toward Getting Help?
Call for guidance or an assessment. The Massachusetts Substance Use Helpline at 800-327-5050 is free, confidential, and available around the clock. A qualified clinician can assess whether withdrawal management is needed. You do not need certainty, a diagnosis, or the person’s agreement to make that call.
Where to Start
If the pattern in this guide matches what you have been watching, the next step is a conversation. Talk to someone who assesses this for a living. The Massachusetts Substance Use Helpline at 800-327-5050, or text HOPE to 800327, is free and confidential at any hour.
New Wave Recovery Center’s drug addiction treatment programs on the North Shore run at every outpatient level. We alsos have a family program for the people who noticed first. When you call, you talk to someone in recovery.
This article is for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Only a qualified clinician can diagnose a substance use disorder. If someone may be overdosing, give naloxone if you have it and call 911. If you are thinking about suicide, call or text 988.
Sources
- Cleveland Clinic. Substance Use Disorder (SUD). Last updated September 9, 2024. https://my.clevelandclinic.org/health/diseases/16652-drug-addiction-substance-use-disorder-sud
- National Institute on Drug Abuse. Drug Misuse and Addiction. Last modified March 9, 2026. https://nida.nih.gov/publications/drugs-brains-behavior-science-addiction/drug-misuse-addiction
- MedlinePlus, National Library of Medicine. Opioid Overdose. Last updated March 25, 2024. https://medlineplus.gov/opioidoverdose.html
- Massachusetts General Laws, Chapter 94C, Section 34A. Overdose-related immunity. https://malegislature.gov/Laws/GeneralLaws/PartI/TitleXV/Chapter94C/Section34A
- Massachusetts Department of Public Health. Massachusetts 2024 Opioid-Involved Overdose Report. https://www.mass.gov/doc/massachusetts-2024-opioid-involved-overdose-report-0/download
- Substance Abuse and Mental Health Services Administration. Key Substance Use and Mental Health Indicators in the United States: Results from the 2025 National Survey on Drug Use and Health. https://www.samhsa.gov/data/sites/default/files/reports/rpt57150/2025-nsduh-annual-national-html/2025-nsduh-annual-national.htm