Understanding Substance Use

For most of history, addiction was treated as a question of morality or willpower. The science tells a different story. Leading medical and research bodies — including the National Institute on Drug Abuse and the American Society of Addiction Medicine — define substance use disorder (SUD)as a chronic, treatable medical condition involving changes to the brain's reward, motivation, and stress circuits.

Repeated substance use can rewire how the brain experiences pleasure and handles stress, driving compulsive use despite mounting harm. That's why "just stopping" is so hard — and why willpower alone often isn't enough. Like diabetes or heart disease, SUD has biological, behavioral, and environmental roots, responds to treatment, and can involve setbacks along the way.

Substance use isn't all-or-nothing. It runs along a continuum, and where someone falls can change over time in either direction. Most people who drink or use a substance never develop a disorder.

When use becomes a disorder, clinicians assess severity using 11 criteria in the DSM-5-TR, grouped into four themes:

• Impaired control — using more or longer than intended, cravings, failed attempts to cut down.
• Social impairment — use disrupting work, school, relationships, or responsibilities.
• Risky use— using in hazardous situations or despite knowing it's causing harm.
• Pharmacological signs — tolerance (needing more) and withdrawal (feeling sick without it).

The number of criteria met defines severity: mild (2–3), moderate (4–5), or severe (6+). Importantly, tolerance and withdrawal alone — common with properly used prescribed medication — do not by themselves mean a disorder.

Different substances act on the body in different ways, but all addictive substances ultimately affect the brain's reward system.

Depressants

Alcohol and benzodiazepines slow the central nervous system. Alcohol is the most widely used and one of the most harmful at a population level. Withdrawal from alcohol or benzodiazepines can be medically dangerous and should be managed with professional support.

Opioids

Heroin, fentanyl, and prescription pain medications relieve pain and produce euphoria, but powerfully suppress breathing in overdose. Illicitly manufactured fentanyl has made the drug supply far more lethal. Opioid use disorder is highly treatable with medication.

Stimulants

Cocaine, methamphetamine, and misused prescription stimulants speed up the nervous system, raising heart rate and blood pressure and carrying risks of cardiac events and severe crashes.

Cannabis and others

Cannabis can be habit-forming for some, particularly with frequent, high-potency use beginning in adolescence. Other categories include hallucinogens and dissociatives. Across all substances, risk rises with younger age of first use, frequency, potency, and mixing.

Recovery is the expected outcome of treatment, not the exception. There is no single right path — what matters is finding the combination that fits the person.

Medication for addiction treatment (MAT / MOUD)

For opioid and alcohol use disorders, medication is the gold standard. For opioids, buprenorphine, methadone, and naltrexone reduce cravings and withdrawal and cut the risk of death by roughly half. For alcohol, naltrexone, acamprosate, and disulfiram help people reduce or stop drinking. Medication is not "replacing one drug with another" — it is evidence-based medical care.

Behavioral therapies

Cognitive behavioral therapy, motivational interviewing, and contingency management help people build coping skills, strengthen motivation, and change patterns — and they work even better alongside medication.

Mutual-help and peer support

• 12-step programs (Alcoholics Anonymous, Narcotics Anonymous) offer a widely available, free fellowship and structure.
• SMART Recovery is a secular, science-based alternative built on cognitive-behavioral and motivational tools.
• Peer recovery support — people with lived experience walking alongside others — is a powerful complement to clinical care.

Care also spans levels of intensity — from outpatient counseling to intensive outpatient, residential, and medically managed withdrawal ("detox") — matched to a person's needs.

Harm reduction is a set of practical, compassionate strategies that aim to reduce the harms associated with substance use — without requiring abstinence as a precondition for help. Its premise is simple and humane: people who are alive can recover; people who have died cannot.

Core principles include:

• Meeting people where they are — offering help and dignity regardless of whether someone is ready or able to stop.
• Keeping people alive and safer — naloxone distribution, fentanyl test strips, and overdose-prevention education.
• Reducing disease and injury — sterile supplies and syringe services that lower HIV and hepatitis transmission.
• Building trust as a bridge to care — nonjudgmental contact that often becomes the doorway into treatment.

New Hampshire has a coordinated system for substance use treatment and recovery, and you don't have to navigate it alone.

• The Doorway-NH — call 2-1-1 or visit any regional Doorway for a single front door to assessment, treatment, and recovery support, 24/7, regardless of insurance.
• 211 NH — free, confidential help connecting to local resources any hour of the day.
• 988— the Suicide & Crisis Lifeline, for mental health and substance use crises alike.