Concerned about a loved one struggling with a substance use disorder? While it isn’t always obvious, most people can recognize the signs of substance abuse once informed. Throughout this article, we’ll detail these signs, categorized by different drugs.

What is a Substance Abuse Disorder?

Substance abuse is defined as the excessive use of a psychoactive drug, including pain medications, alcohol, or illegal substances. A substance use disorder is deemed a problem once it has consequential effects on an individual and those around them (physical, social, and emotional harm). ¹

How is Substance Abuse Diagnosed?

For a person to struggle with drug addiction, they must meet at least three of the following diagnostic criteria: ²

1. A substance is taken in larger amounts or over a long period.
2. There is a persistent desire or unsuccessful effort to cut down/control the use of a substance.
3. They take considerable time to obtain, use, or recover from a substance.
4. Cravings (a strong desire to use a substance).
5. Substance use results in failure to fulfill major role obligations at work, school, or home.
6. Substance continues despite persistent social or interpersonal problems.
7. Reduction in important social, occupational, or recreational activities.
8. Putting themselves in physical hazards for a substance (i.e. prostitution).
9. Continual substance use despite having persistent or recurrent physical/psychological problems.
10. Tolerance, as defined by either:
    1. A need for markedly increased amounts of a substance to achieve intoxication.
    2. A markedly diminished effect with continued use.
11. Withdrawal, as manifested by either:
    1. Characteristic withdrawal syndrome for that substance.
    2. The use of a substance (or a closely related substance) to relieve or avoid withdrawal symptoms.

Signs of Substance Abuse

The signs of a substance use disorder can be divided into three categories. These are as follows:

Behavioral Signs

One of the initial signs you may notice from substance use is behavioral. These outward displays may include: ³

• Changes in attitude/personality
• Depression
• Dramatic changes in habits and/or priorities
• Increased aggression or irritability
• Involvement in criminal activity
• Lethargy
• Sudden changes in a social network

Physical Signs

The easiest signs to pick up are physical. As your loved one goes through the stages of addiction, they may reveal the following: ⁴

• Bloodshot eyes and abnormally sized pupils
• Deterioration of physical appearance
• Impaired coordination
• Slurred speech
• Sudden weight loss or weight gain
• Tremors and muscle spasms
• Unusual smells on breath, body, or clothing

Psychological Signs

While not as outward in appearance, your loved one may also reveal the following psychological signs: ⁵

• Anxiety and depression
• Irritability and mood swings
• Low self-esteem
• Poor motivation
• Suicidal ideation

Signs of Substance Abuse Among Age and Gender

Anyone of any age can experience substance abuse. However, the most obvious impact will be on teenagers since their brains are still developing. As a result, drug use can lead to long-term damage. For example, one study found that marijuana use among teenage girls may result in higher brain structural abnormalities than boys. ⁶

That being said, women may reveal the following signs of substance use:

• Behavioral changes or secrecy
• Changes in eating habits
• Concerning physical appearance
• Drowsiness or fatigue
• Eye redness
• Financial difficulties
• Guarded about substance use
• Poor academic performance
• Reduced job productivity
• Slurred speech
• Spending beyond usual limits
• Unexplained weight fluctuations

On the other hand, men are more likely to:

• Anxiety and paranoia
• Bad hygiene
• Defensiveness
• Disregard of the risk factors
• Inattentiveness or irritability
• Lack of motivation
• Poor financial decisions

Keep in mind that these signs can overlap between genders.

Substance Abuse Signs by Drug

To further understand the signs of substance abuse, here they are categorized by drug:

Alcohol

Alcohol is one of the most commonly available and widely used substances among Americans. Annually, around 95,000 people die from alcohol-related causes in the United States. ⁷ Most of these deaths were caused by health disorders of long-term drinking, such as: ⁸

• Heart disease
• Liver disease
• Liver cirrhosis
• Renal failure
• Stroke
• Upper aerodigestive tract cancers

The most common warning signs of continual use and abuse of alcohol are: ⁹

• Anxiety
• Appetite changes
• Binge drinking (or drinking to excess)
• Depression
• Fatigue
• Fluctuations of weight (either gaining or losing weight)
• Irritability
• Loss in social interactions
• Nausea and or vomiting

Cannabis

With legality across the United States, cannabis (or marijuana) has become one of the most widely used drugs. However, even though it’s safer than most substances, it can still cause addiction and other consequences. These include: ¹⁰

• An inability to attend to daily responsibilities
• Changing relationships or activities due to the use of marijuana
• Continuing to use marijuana despite the problems it causes
• Decrease in overall happiness and fulfillment that life usually gives someone
• Depending on marijuana to be creative, relax, or enjoy yourself
• Lethargy and lack of energy
• Unable to cut back or stop marijuana use
• Using marijuana to deal with external or internal complications

Not to mention, cannabis use can cause cannabinoid hyperemesis syndrome (CHS). This is a clinical diagnosis characterized by chronic cannabis use. Its symptoms include: ¹¹

• Decreased appetite
• Increased nausea
• Upset stomach
• Vomiting

Signs of cannabis use include: ¹²

• Dry mouth
• Bloodshot or glassy eyes
• Delayed reaction time
• Impaired motor skills
• Increased appetite
• Lack of ability to focus
• Memory problems
• Panic attacks (or paranoia)
• Poor coordination
• Trouble with decision-making

Depressants

Depressants are medications that include:

• Hypnotics
• Sedatives
• Tranquilizers

Since they slow brain activity, they’ve been a go-to for treating anxiety, panic attacks, acute stress reactions, and sleep disorders. However, depressants run a high risk for addiction. Overuse can lead to problems with daily responsibilities, confusion, decreased brain functionality, and overdoses. ¹³

The most common warning signs and symptoms of depressant abuse are: ¹⁴

• Depression
• Difficulty or inability to urinate
• Dilated pupils
• Disorientation, lack of coordination
• Dizziness
• Fever
• Poor concentration
• Slow brain function
• Slowed pulse and breathing
• Sluggishness
• Slurred speech
• Visual disturbances

Heroin (and Other Opioids)

Over the past few decades, opioid use has been on the rise in the United States. These are substances that act on opioid receptors to help relieve pain and provide euphoria. In the medical field, they’re primarily used for short-term pain relief or as anesthesia.

As more people are prescribed opiates, opioid addiction (and subsequent overdoses) also increases. This has resulted in many turning to the streets for unsafe opioid alternatives, such as heroin.

In 2019, opioids were involved in 49,860 overdose deaths in the United States alone. Heroin was responsible for over 14,000 deaths of those deaths. ¹⁵

The warning signs of opioid addiction include: ¹⁶

• Bruises or scabs from skin-picking
• Burn marks on fingers or mouth
• Constipation (from abuse), or diarrhea (from withdrawal)
• Dry mouth
• Eyelids and arms/legs appear heavy
• Flu-like symptoms (i.e. fever, aches, vomiting, always cold)
• Infections or abscesses (from injecting)
• Lack of hygiene and disregard for physical appearance
• Nosebleeds (from snorting)
• Persistent hack
• Pinpoint pupils
• Runny nose or constant sniffing
• Sores on nostrils or lips

Stimulants (Cocaine, Crack, and Methamphetamine)

Stimulants are a class of drugs that increase dopamine, a “feel good” chemical messenger. Dopamine affects the pleasure and reward center of the brain and can also affect movement, focus, and motivation. Stimulants are highly addictive and only require a small amount to cause an overdose.

The warning signs of an abuse of stimulants are: ¹⁷

• Agitation
• Feeling high
• High body temperature and blood pressure
• Increased alertness
• Insomnia
• Irregular heartbeat
• Paranoia (or general anxiety)
• Reduced appetite

References

¹ Volkow ND, Blanco C. Substance use disorders: a comprehensive update of classification, epidemiology, neurobiology, clinical aspects, treatment and prevention. World Psychiatry. 2023 Jun;22(2):203-229. doi: 10.1002/wps.21073. PMID: 37159360; PMCID: PMC10168177.

² Hasin DS, O’Brien CP, Auriacombe M, Borges G, Bucholz K, Budney A, Compton WM, Crowley T, Ling W, Petry NM, Schuckit M, Grant BF. DSM-5 criteria for substance use disorders: recommendations and rationale. Am J Psychiatry. 2013 Aug;170(8):834-51. doi: 10.1176/appi.ajp.2013.12060782. PMID: 23903334; PMCID: PMC3767415.

³ Institute of Medicine (US) Committee on Opportunities in Drug Abuse Research. Pathways of Addiction: Opportunities in Drug Abuse Research. Washington (DC): National Academies Press (US); 1996. 2, Behavioral Research. Available from: https://www.ncbi.nlm.nih.gov/books/NBK232968/

⁴ Fluyau D, Hashmi MF, Charlton TE. Drug Addiction. [Updated 2024 Jan 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549783/

⁵ Booth BM, Curran G, Han X, Wright P, Frith S, Leukefeld C, Falck R, Carlson RG. Longitudinal relationship between psychological distress and multiple substance use: results from a three-year multisite natural-history study of rural stimulant users. J Stud Alcohol Drugs. 2010 Mar;71(2):258-67. doi: 10.15288/jsad.2010.71.258. PMID: 20230724; PMCID: PMC2841737.

⁶ Jacobus J, Tapert SF. Effects of cannabis on the adolescent brain. Curr Pharm Des. 2014;20(13):2186-93. doi: 10.2174/13816128113199990426. PMID: 23829363; PMCID: PMC3930618.

⁷ Esser MB, Idaikkadar N, Kite-Powell A, Thomas C, Greenlund KJ. Trends in emergency department visits related to acute alcohol consumption before and during the COVID-19 pandemic in the United States, 2018-2020. Drug Alcohol Depend Rep. 2022 Jun;3:100049. doi: 10.1016/j.dadr.2022.100049. Epub 2022 Mar 27. PMID: 35368619; PMCID: PMC8957715.

⁸ Hendriks HFJ. Alcohol and Human Health: What Is the Evidence? Annu Rev Food Sci Technol. 2020 Mar 25;11:1-21. doi: 10.1146/annurev-food-032519-051827. PMID: 32209032.

⁹ Nehring SM, Chen RJ, Freeman AM. Alcohol Use Disorder. [Updated 2024 Mar 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK436003/

¹⁰ Zehra A, Burns J, Liu CK, Manza P, Wiers CE, Volkow ND, Wang GJ. Cannabis Addiction and the Brain: a Review. J Neuroimmune Pharmacol. 2018 Dec;13(4):438-452. doi: 10.1007/s11481-018-9782-9. Epub 2018 Mar 19. PMID: 29556883; PMCID: PMC6223748.

¹¹ Galli JA, Sawaya RA, Friedenberg FK. Cannabinoid hyperemesis syndrome. Curr Drug Abuse Rev. 2011 Dec;4(4):241-9. doi: 10.2174/1874473711104040241. PMID: 22150623; PMCID: PMC3576702.

¹² Kesner AJ, Lovinger DM. Cannabis use, abuse, and withdrawal: Cannabinergic mechanisms, clinical, and preclinical findings. J Neurochem. 2021 Jun;157(5):1674-1696. doi: 10.1111/jnc.15369. Epub 2021 May 16. PMID: 33891706; PMCID: PMC9291571.

¹³ National Guideline Centre (UK). Evidence review: Risk factors for dependence: Medicines associated with dependence or withdrawal symptoms: safe prescribing and withdrawal management for adults: Evidence review E. London: National Institute for Health and Care Excellence (NICE); 2022 Apr. (NICE Guideline, No. 215.) Available from: https://www.ncbi.nlm.nih.gov/books/NBK580678/

¹⁴ Quello SB, Brady KT, Sonne SC. Mood disorders and substance use disorder: a complex comorbidity. Sci Pract Perspect. 2005 Dec;3(1):13-21. doi: 10.1151/spp053113. PMID: 18552741; PMCID: PMC2851027.

¹⁵ Mattson CL, Tanz LJ, Quinn K, Kariisa M, Patel P, Davis NL. Trends and Geographic Patterns in Drug and Synthetic Opioid Overdose Deaths – United States, 2013-2019. MMWR Morb Mortal Wkly Rep. 2021 Feb 12;70(6):202-207. doi: 10.15585/mmwr.mm7006a4. PMID: 33571180; PMCID: PMC7877587.

¹⁶ Dydyk AM, Jain NK, Gupta M. Opioid Use Disorder. [Updated 2024 Jan 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553166/

¹⁷ Farzam K, Faizy RM, Saadabadi A. Stimulants. [Updated 2023 Jul 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539896/