Chapter 16: Clinical, Social, and Policy Profiles of Substances

Prevalence and patterns of use

Opioids include both prescription pain medications (such as oxycodone, hydrocodone, and morphine) and illicit substances (such as heroin and illicitly manufactured fentanyl). The United States has experienced a multi-phase opioid crisis beginning with overprescribing in the 1990s, followed by increased heroin use when prescription access tightened, and now dominated by synthetic opioids, primarily fentanyl, which are present in much of the illicit drug supply (Centers for Disease Control and Prevention, 2025). Opioid use disorder affects millions of Americans, and opioid overdose is among the leading causes of accidental death in the United States (National Safety Council, 2025).

Effects and pharmacology

Opioids act primarily on mu-opioid receptors in the brain and throughout the body, producing analgesia, euphoria, sedation, and respiratory depression. Physical dependence develops rapidly; tolerance requires increasing doses to achieve the same effect. Withdrawal is intensely uncomfortable but generally not life-threatening, though the discomfort drives continued use and complicates detoxification (World Health Organization, 2009). Overdose, characterized by respiratory depression, unconsciousness, and cyanosis, is rapidly fatal without intervention (National Institute on Drug Abuse [NIDA], 2020).

Risk and protective factors

Risk factors include genetic predisposition, prior trauma and adverse childhood experiences, chronic pain, mental health co-occurring conditions, early substance use initiation, and access to prescription opioids (NIDA, 2020). Protective factors include social support, stable housing, employment, access to substance use treatment, and family connection.

Systems and policy context

The opioid crisis has prompted significant policy responses including expanded access to naloxone, medications for opioid use disorder, and syringe services programs. Racial disparities in treatment access remain pronounced. White Americans have been substantially more likely than Black Americans to receive buprenorphine for opioid use disorder, a divide tied to both race and how care is paid for (Lagisetty et al., 2019). That uneven access sits within a longer history, examined earlier in this text, in which communities of color have more often encountered criminal justice responses to substance use than treatment.

Evidence-informed prevention and treatment

Medications for opioid use disorder, including methadone, buprenorphine, and extended-release naltrexone, are the gold standard of treatment and dramatically reduce overdose mortality, criminal activity, and transmission of infectious diseases (Sordo et al., 2017). Community naloxone distribution reduces overdose mortality. In the Massachusetts program that established the finding, opioid overdose death rates were 27 percent lower in communities with low program implementation and 46 percent lower in communities with high implementation, compared with communities that had no program at all (Walley et al., 2013). A later systematic review and meta-analysis found that community and police-based naloxone programs remained effective through the fentanyl era (Fischer et al., 2025). Broader harm reduction strategies, including syringe services and fentanyl test strips, reduce harm and can serve as bridges to treatment engagement.

Social work assessment considerations

Assessment should address the full context of opioid use including chronic pain, trauma history, co-occurring mental health conditions, social support, and structural barriers to treatment access. Practitioners should be familiar with medications for opioid use disorder and support clients in accessing it without imposing personal beliefs about recovery pathways.

Prevalence and patterns of use

Alcohol is the most widely used substance in the United States and one of the most significant contributors to disability, chronic disease, and premature death. In 2025, an estimated 25.7 million people aged 12 and older in the United States, or 8.9 percent of that population, had an alcohol use disorder (Substance Abuse and Mental Health Services Administration, 2026). Heavy use is patterned by age, gender, race, socioeconomic status, and geography, with significant disparities in both use patterns and consequences across demographic groups.

Effects and pharmacology

Alcohol acts as a central nervous system depressant through effects on gamma-aminobutyric acid (GABA) and glutamate neurotransmitter systems. At low doses it produces disinhibition, relaxation, and mild euphoria. At higher doses it produces sedation, impaired coordination and judgment, and can cause acute respiratory depression and death. Chronic heavy use produces tolerance and physical dependence; alcohol withdrawal, unlike opioid withdrawal, can be medically life-threatening, including the risk of seizures and delirium tremens (NIDA, 2020).

Risk and protective factors

Genetic heritability accounts for approximately 50 percent of the risk for alcohol use disorder (Edenberg et al., 2019), a figure that sits inside the 40 to 60 percent range Chapter 3 reports for addiction risk across substances. Adverse childhood experiences, trauma, depression, anxiety, family history, and early onset of use are established risk factors. Protective factors include strong family bonds, religious or spiritual involvement, school connectedness, and access to behavioral health services.

Systems and policy context

Alcohol is heavily marketed and normalized within American culture, with significant variation in state and local policies governing access, pricing, and availability. Alcohol use disorder has historically been undertreated relative to its public health burden. Brief intervention approaches within primary care settings, embodied in the Screening, Brief Intervention, and Referral to Treatment (SBIRT) framework, are among the most cost-effective public health interventions available (Maciosek et al., 2017).

Evidence-informed prevention and treatment

Cognitive behavioral therapy, motivational interviewing, twelve-step facilitation, and behavioral couples therapy all demonstrate evidence of effectiveness for alcohol use disorder. Food and Drug Administration (FDA)-approved medications include naltrexone, acamprosate, and disulfiram (National Institute on Alcohol Abuse and Alcoholism, 2025). Medically supervised withdrawal management is essential for individuals with significant physical dependence.

Social work assessment considerations

Alcohol use is often underreported and undertreated in clinical settings because it is normalized and its consequences develop gradually. Social workers should routinely screen for alcohol use across practice settings and be attentive to the interaction between alcohol use and co-occurring depression, anxiety, trauma, and family systems concerns.

Prevalence and patterns of use

Stimulants include cocaine, methamphetamine, and prescription stimulants (amphetamines and methylphenidate). Methamphetamine use has increased significantly in recent years across rural and urban communities (Han et al., 2021), and stimulant involvement in overdose deaths, particularly in combination with synthetic opioids, has grown substantially (Tanz et al., 2024). Cocaine use has also increased, with powder and crack cocaine disproportionately concentrated in different demographic and geographic populations.

Effects and pharmacology

Stimulants act primarily by increasing dopamine, norepinephrine, and serotonin availability in the brain, producing heightened energy, alertness, euphoria, and decreased appetite. Chronic use depletes dopamine systems, producing anhedonia, depression, cognitive impairment, and intense cravings during abstinence. Methamphetamine in particular is associated with significant neurotoxicity and lasting cognitive effects (Paulus & Stewart, 2020). Stimulant withdrawal, while not medically dangerous, involves profound psychological distress including depression, fatigue, and hypersomnia (NIDA, 2020).

Risk and protective factors

Risk factors include prior trauma, depression, poverty, housing instability, peer networks that normalize use, and access to substances. Rural communities face particular challenges related to methamphetamine availability. Protective factors include social connection, stable employment, mental health treatment, and family support.

Systems and policy context

Stimulant use disorder presents a significant treatment gap: unlike opioid use disorder, there are currently no FDA-approved medications for stimulant use disorder (Ronsley et al., 2020). Criminalization of stimulant use, particularly crack cocaine, has carried profound racial disparities since the 1980s, when sentences for crack were dramatically harsher than those for powder cocaine. The Anti-Drug Abuse Act of 1986 established a 100-to-1 sentencing disparity between crack and powder cocaine, which the Fair Sentencing Act of 2010 reduced to 18 to 1 (Congressional Research Service, 2022).

Evidence-informed prevention and treatment

Contingency management, the use of incentives to reinforce abstinence and treatment engagement, has the strongest evidence base for stimulant use disorders and is designated as an evidence-based practice by SAMHSA (Ronsley et al., 2020). Cognitive behavioral therapy and motivational interviewing also demonstrate effectiveness. Community reinforcement approaches attempt to reshape social and environmental reinforcers to support recovery.

Social work assessment considerations

Assessment should attend to the interaction between stimulant use, mental health conditions (particularly depression and anxiety), housing stability, and social context. Practitioners should be familiar with contingency management approaches and aware of the lack of pharmacological treatment options when coordinating care.

Prevalence and patterns of use

Cannabis is the most widely used illicit substance in the United States, with use increasing following decades of policy liberalization and legalization in multiple states. Cannabis use disorder affects a meaningful subset of regular users, particularly those who initiate use in adolescence. Classic hallucinogens, including lysergic acid diethylamide (LSD), psilocybin, and methylenedioxymethamphetamine (MDMA), are experiencing renewed research attention for potential therapeutic applications alongside continued recreational use.

Effects and pharmacology

Cannabis acts primarily through the endocannabinoid system, producing altered perception, relaxation, euphoria, impaired short-term memory, and, in high doses or in vulnerable individuals, anxiety and paranoia. Chronic heavy use is associated with cognitive effects particularly when initiation occurs during adolescence. Hallucinogens act primarily through serotonergic systems, producing altered sensory perception, changes in thought, and intensified emotional experiences (NIDA, 2020).

Risk and protective factors

Adolescent-onset cannabis use is a well-established risk factor for developing cannabis use disorder, and risk rises with more frequent use (Centers for Disease Control and Prevention, 2024). Genetic vulnerability, trauma exposure, co-occurring mental health conditions, particularly psychosis and anxiety, and social network factors all influence risk. The relationship between cannabis and psychosis is an area of active research, with heavy use in genetically vulnerable individuals associated with increased risk for psychotic symptoms (Di Forti et al., 2019).

Systems and policy context

Cannabis policy is in significant flux across the United States, with a patchwork of state legalization, decriminalization, and prohibition creating complex legal and clinical contexts. Racial disparities in cannabis-related arrests have persisted even in states that have legalized (American Civil Liberties Union, 2020). Psilocybin and MDMA have been studied in late-stage clinical trials for posttraumatic stress disorder (PTSD) and treatment-resistant depression, though their regulatory paths have diverged. In August 2024 the Food and Drug Administration (FDA) declined to approve MDMA-assisted therapy for PTSD, issuing a complete response letter that required an additional phase 3 trial (Lykos Therapeutics, 2024). A randomized phase 2b trial of a synthetic psilocybin formulation found that a single 25 mg dose produced a significantly greater reduction in depression scores at three weeks than a 1 mg control, though adverse events occurred and sustained response at twelve weeks was not statistically significant (Goodwin et al., 2022). No psychedelic-assisted therapy is currently approved for clinical use in the United States. Practitioners should follow this literature as it develops rather than treat these therapies as available options.

Evidence-informed prevention and treatment

Motivational enhancement therapy and cognitive behavioral therapy demonstrate the strongest evidence for cannabis use disorder. No medications are currently FDA-approved for cannabis use disorder (NIDA, 2024b). For adolescents, multidimensional family therapy and the Adolescent Community Reinforcement Approach (A-CRA) have evidence of effectiveness (Dennis et al., 2004).

Social work assessment considerations

Practitioners should assess cannabis use without judgment, attending to frequency, potency, method of use, context, and the presence of use disorder symptoms rather than defaulting to categorical abstinence-based frameworks. Assessment should also explore the interaction between cannabis use and mental health, particularly anxiety, depression, and psychosis risk.

Prevalence and patterns of use

Sedative-hypnotics include benzodiazepines (such as diazepam, alprazolam, and clonazepam), barbiturates, and the newer non-benzodiazepine sleep medications. Benzodiazepines are widely prescribed for anxiety and sleep disorders, and misuse, including both non-prescribed use and use beyond prescribed parameters, is common. Their combination with opioids dramatically increases overdose risk and is involved in a significant proportion of opioid-related deaths (Sun et al., 2017).

Effects and pharmacology

Sedative-hypnotics act on GABA receptors, producing anxiolytic, sedative, muscle-relaxant, and anticonvulsant effects. Physical dependence develops with regular use, often more quickly than users anticipate. Withdrawal from benzodiazepines and barbiturates can be severe and life-threatening, comparable to alcohol withdrawal, requiring medically supervised tapering rather than abrupt discontinuation (NIDA, 2020).

Risk and protective factors

Risk factors include anxiety disorders (for which benzodiazepines may be prescribed), prior trauma, co-occurring opioid use, older age, and prolonged prescription use. Healthcare prescribing patterns and patient-provider communication represent structural factors that shape risk. Protective factors include access to non-pharmacological anxiety treatment and strong therapeutic relationships with prescribers.

Systems and policy context

Concerns about benzodiazepine overprescribing parallel concerns about opioid prescribing, with growing recognition that long-term benzodiazepine use carries significant risks and limited long-term efficacy for anxiety treatment (Robertson et al., 2023). Concurrent benzodiazepine and opioid prescribing represents a major patient safety concern.

Evidence-informed prevention and treatment

Gradual medically supervised tapering is the standard approach for benzodiazepine discontinuation (Robertson et al., 2023). Cognitive behavioral therapy for anxiety and insomnia (CBT-I) demonstrates strong evidence as an alternative to pharmacological treatment (Qaseem et al., 2016). Motivational interviewing and psychoeducation support treatment engagement.

Social work assessment considerations

Social workers in healthcare settings should be familiar with the risks associated with long-term benzodiazepine use and the dangers of concurrent use with opioids. Assessment should include questions about prescribed and non-prescribed sedative use, and practitioners should understand that withdrawal from these substances requires medical supervision.

Inhalants

Inhalants are a diverse group of volatile substances, including household solvents, aerosols, and gases, that are inhaled to produce intoxicating effects. Use is concentrated disproportionately among young adolescents (NIDA, 2024c). Inhalant use can cause sudden death through cardiac arrhythmia, asphyxiation, or aspiration, and chronic use is associated with significant neurological damage (NIDA, 2020).

Anabolic Steroids

Anabolic-androgenic steroids are used non-medically to enhance athletic performance and physical appearance. Use occurs predominantly among boys and young men and most commonly begins in young adulthood, particularly in sports and bodybuilding contexts (NIDA, 2024a). Health risks include cardiovascular complications, hormonal disruption, liver damage, and psychiatric effects including aggression and mood instability. Dependence and withdrawal syndromes have been documented with chronic use (NIDA, 2024a).

Prescription and Over-the-Counter Drug Misuse

Misuse of prescription medications beyond opioids, benzodiazepines, and stimulants includes cough and cold medications containing dextromethorphan (DXM), antihistamines, and other OTC substances. These patterns are particularly relevant in adolescent populations (Bryner et al., 2006). Assessment should routinely address prescription and OTC medication use without assuming that legally available substances are safe when used outside prescribed parameters.

Social work assessment considerations

Practitioners working with adolescents and young adults should be aware of inhalant and steroid use and include these substances in routine screening. Assessment should be non-judgmental and developmentally appropriate. Practitioners should also understand that any substance, including legally available ones, can be misused, and should approach assessment with curiosity about the full range of substances a person may be using.

Comprehensive assessment. An assessment lens that reaches beyond illicit drugs to include prescription and over-the-counter medications, inhalants, and performance-enhancing substances.

Hallucinogens. A class including LSD, psilocybin, and MDMA, some of which are under renewed clinical study for conditions such as PTSD and depression.

Inhalants. A diverse group of volatile substances, including household solvents, aerosols, and gases, inhaled to produce intoxicating effects, with use most common among adolescents.

Naloxone. An opioid antagonist that reverses opioid overdose by displacing opioids from mu-opioid receptors and restoring breathing, available without a prescription as a nasal spray.

Opioids. A category including prescription pain medications and illicit substances such as heroin and fentanyl, acting on mu-opioid receptors and carrying a high risk of fatal respiratory depression.

Physical dependence. A physiological adaptation in which stopping a substance produces withdrawal, distinct from addiction.

Sedative-hypnotics. Central nervous system depressants, including benzodiazepines and barbiturates, prescribed for anxiety and sleep, with withdrawal that can be severe and life-threatening.

Stimulants. Substances such as cocaine and methamphetamine that increase central nervous system activity; contingency management has the strongest evidence base for treating stimulant use disorder.

Tolerance. A state in which increasing doses of a substance are needed to achieve the same effect.

American Civil Liberties Union. (2020). A tale of two countries: Racially targeted arrests in the era of marijuana reform. https://www.aclu.org/report/tale-two-countries-racially-targeted-arrests-era-marijuana-reform

Bryner, J. K., Wang, U. K., Hui, J. W., Bedodo, M., MacDougall, C., & Anderson, I. B. (2006). Dextromethorphan abuse in adolescence: An increasing trend, 1999–2004. Archives of Pediatrics & Adolescent Medicine, 160(12), 1217–1222. https://doi.org/10.1001/archpedi.160.12.1217

Centers for Disease Control and Prevention. (2024). Cannabis use disorder. U.S. Department of Health and Human Services. https://www.cdc.gov/cannabis/health-effects/cannabis-use-disorder.html

Centers for Disease Control and Prevention. (2025). Understanding the opioid overdose epidemic. U.S. Department of Health and Human Services. https://www.cdc.gov/overdose-prevention/about/understanding-the-opioid-overdose-epidemic.html

Congressional Research Service. (2022). Cocaine: Crack and powder sentencing disparities (Report No. IF11965). https://www.congress.gov/crs-product/IF11965

Dennis, M., Godley, S. H., Diamond, G., Tims, F. M., Babor, T., Donaldson, J., Liddle, H., Titus, J. C., Kaminer, Y., Webb, C., Hamilton, N., & Funk, R. (2004). The Cannabis Youth Treatment (CYT) study: Main findings from two randomized trials. Journal of Substance Abuse Treatment, 27(3), 197–213. https://doi.org/10.1016/j.jsat.2003.09.005

Di Forti, M., Quattrone, D., Freeman, T. P., Tripoli, G., Gayer-Anderson, C., Quigley, H., Rodriguez, V., Jongsma, H. E., Ferraro, L., La Cascia, C., La Barbera, D., Tarricone, I., Berardi, D., Szöke, A., Arango, C., Tortelli, A., Velthorst, E., Bernardo, M., Del-Ben, C. M., … Murray, R. M. (2019). The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): A multicentre case-control study. The Lancet Psychiatry, 6(5), 427–436. https://doi.org/10.1016/S2215-0366(19)30048-3

Edenberg, H. J., Gelernter, J., & Agrawal, A. (2019). Genetics of alcoholism. Current Psychiatry Reports, 21(4), Article 26. https://doi.org/10.1007/s11920-019-1008-1

Fischer, L. S., Asher, A., Stein, R., Becasen, J., Doreson, A., Mermin, J., Meltzer, M. I., & Edlin, B. R. (2025). Effectiveness of naloxone distribution in community settings to reduce opioid overdose deaths among people who use drugs: A systematic review and meta-analysis. BMC Public Health, 25(1), Article 1135. https://doi.org/10.1186/s12889-025-22210-8

Goodwin, G. M., Aaronson, S. T., Alvarez, O., Arden, P. C., Baker, A., Bennett, J. C., Bird, C., Blom, R. E., Brennan, C., Brusch, D., Burke, L., Campbell-Coker, K., Carhart-Harris, R., Cattell, J., Daniel, A., DeBattista, C., Dunlop, B. W., Eisen, K., Feifel, D., … Malievskaia, E. (2022). Single-dose psilocybin for a treatment-resistant episode of major depression. New England Journal of Medicine, 387(18), 1637–1648. https://doi.org/10.1056/NEJMoa2206443

Han, B., Compton, W. M., Jones, C. M., Einstein, E. B., & Volkow, N. D. (2021). Methamphetamine use, methamphetamine use disorder, and associated overdose deaths among US adults. JAMA Psychiatry, 78(12), 1329–1342. https://doi.org/10.1001/jamapsychiatry.2021.2588

Lagisetty, P. A., Ross, R., Bohnert, A., Clay, M., & Maust, D. T. (2019). Buprenorphine treatment divide by race/ethnicity and payment. JAMA Psychiatry, 76(9), 979–981. https://doi.org/10.1001/jamapsychiatry.2019.0876

Lykos Therapeutics. (2024, August 9). Lykos Therapeutics announces complete response letter for midomafetamine capsules for PTSD [Press release]. PR Newswire. https://www.prnewswire.com/news-releases/lykos-therapeutics-announces-complete-response-letter-for-midomafetamine-capsules-for-ptsd-302219182.html

Maciosek, M. V., LaFrance, A. B., Dehmer, S. P., McGree, D. A., Flottemesch, T. J., Xu, Z., & Solberg, L. I. (2017). Updated priorities among effective clinical preventive services. Annals of Family Medicine, 15(1), 14–22. https://doi.org/10.1370/afm.2017

National Institute on Alcohol Abuse and Alcoholism. (2025). Recommend evidence-based treatment: Know the options. The healthcare professional’s core resource on alcohol. National Institutes of Health. https://www.niaaa.nih.gov/health-professionals-communities/core-resource-on-alcohol/recommend-evidence-based-treatment-know-options

National Institute on Drug Abuse. (2020). Drugs, brains, and behavior: The science of addiction. U.S. Department of Health and Human Services, National Institutes of Health. https://nida.nih.gov/publications/drugs-brains-behavior-science-addiction

National Institute on Drug Abuse. (2024a). Anabolic steroids. National Institutes of Health. https://nida.nih.gov/research-topics/anabolic-steroids

National Institute on Drug Abuse. (2024b). Cannabis (marijuana). National Institutes of Health. https://nida.nih.gov/research-topics/cannabis-marijuana

National Institute on Drug Abuse. (2024c). Inhalants. National Institutes of Health. https://nida.nih.gov/research-topics/inhalants

National Safety Council. (2025). Preventable death overview: Odds of dying. Injury Facts. https://injuryfacts.nsc.org/all-injuries/preventable-death-overview/odds-of-dying/

Paulus, M. P., & Stewart, J. L. (2020). Neurobiology, clinical presentation, and treatment of methamphetamine use disorder: A review. JAMA Psychiatry, 77(9), 959–966. https://doi.org/10.1001/jamapsychiatry.2020.0246

Qaseem, A., Kansagara, D., Forciea, M. A., Cooke, M., & Denberg, T. D. (2016). Management of chronic insomnia disorder in adults: A clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 165(2), 125–133. https://doi.org/10.7326/M15-2175

Robertson, S., Peacock, E. E., & Scott, R. (2023). Benzodiazepine use disorder: Common questions and answers. American Family Physician, 108(3), 260–266.

Ronsley, C., Nolan, S., Knight, R., Hayashi, K., Klimas, J., Walley, A., Wood, E., & Fairbairn, N. (2020). Treatment of stimulant use disorder: A systematic review of reviews. PLOS ONE, 15(6), Article e0234809. https://doi.org/10.1371/journal.pone.0234809

Sordo, L., Barrio, G., Bravo, M. J., Indave, B. I., Degenhardt, L., Wiessing, L., Ferri, M., & Pastor-Barriuso, R. (2017). Mortality risk during and after opioid substitution treatment: Systematic review and meta-analysis of cohort studies. BMJ, 357, Article j1550. https://doi.org/10.1136/bmj.j1550

Substance Abuse and Mental Health Services Administration. (2026). Key substance use and mental health indicators in the United States: Results from the 2025 National Survey on Drug Use and Health. Center for Behavioral Health Statistics and Quality, Substance Abuse and Mental Health Services Administration. https://www.samhsa.gov/data/report/2025-nsduh-annual-national-report

Sun, E. C., Dixit, A., Humphreys, K., Darnall, B. D., Baker, L. C., & Mackey, S. (2017). Association between concurrent use of prescription opioids and benzodiazepines and overdose: Retrospective analysis. BMJ, 356, Article j760. https://doi.org/10.1136/bmj.j760

Tanz, L. J., Gladden, R. M., Dinwiddie, A. T., Miller, K. D., Broz, D., Spector, E., & O’Donnell, J. (2024). Routes of drug use among drug overdose deaths — United States, 2020–2022. MMWR Morbidity and Mortality Weekly Report, 73(6), 124–130. https://www.cdc.gov/mmwr/volumes/73/wr/mm7306a2.htm

Walley, A. Y., Xuan, Z., Hackman, H. H., Quinn, E., Doe-Simkins, M., Sorensen-Alawad, A., Ruiz, S., & Ozonoff, A. (2013). Opioid overdose rates and implementation of overdose education and nasal naloxone distribution in Massachusetts: Interrupted time series analysis. BMJ, 346, Article f174. https://doi.org/10.1136/bmj.f174

World Health Organization. (2009). Clinical guidelines for withdrawal management and treatment of drug dependence in closed settings. https://www.who.int/publications/i/item/9789290614302