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Is Drug Addiction a Mental Illness?
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Is Drug Addiction a Mental Illness?

Written by Seth Fletcher on January 10, 2015
Medical editor Victoria Perez Gonzalez
Last update: May 29, 2024

Drug addiction is a complex condition where uncontrolled substance use by an individual often leads to harmful effects. A person with drug addiction will make taking their drug of choice their priority and may be unable to function normally without it. This is because continued use of certain drugs changes the fundamental structure of the brain, altering a person’s normal hierarchy of desires and impulse control mechanisms.

So is drug addiction a mental illness? The DSM-5 – the diagnostic reference for mental illnesses used by healthcare professionals in Canada and the United States – includes criteria for drug use disorders, distinguishing between drug abuse and drug dependence (addiction). The diagnostic criteria for drug abuse stem from the harmful effects of repeatedly using a substance, while that for addiction includes compulsive use, tolerance, and withdrawal symptoms. Today, leading scientific bodies agree that drug addiction is a mental illness requiring medical treatment. We explain why drug addiction is a mental illness and how those suffering from it or who have loved ones with drug addiction can get help. 

Key Takeaways

  • Drug addiction is a mental illness that makes an individual unable to stop using a substance despite obvious harmful consequences. 
  • Addiction still carries a lot of societal stigmas even though research proves it’s a disease. 
  • Addiction and mental illness have similar risk factors, and one may lead to the other.
  • Addiction and mental illness often co-occur in patients, and dual treatment approaches are necessary in such cases. 

Yes, Drug Addiction Is a Mental Illness

Decades of clinical research have resulted in the widely accepted understanding that drug addiction is a mental illness. The DSM-5 criteria for substance disorders cover the use of 10 separate classes of drugs:

  • Alcohol 
  • Opioids
  • Hallucinogens
  • Inhalants
  • Caffeine
  • Tobacco
  • Stimulants
  • Anxiolytics/Hypnotics
  • Sedative
  • Cannabis

These substances have different pharmacological mechanisms but activate the brain’s reward system to produce euphoric sensations or “highs.” Some of these substances produce a high so intense that they rewire the brain and make the individual crave them above every other thing. Not everyone is affected the same way by these substances. People with lower levels of self-control are more likely to become addicted to alcohol and other drugs, and individuals with existing mental health disorders are also more vulnerable to drug addiction. The DSM-5 criteria for drug addiction or substance disorders cover the following symptoms: 

  • Using the drug in higher amounts or for longer than intended
  • Wanting to reduce or stop drug use without success
  • Continued use of the substance to the detriment of personal relationships 
  • Having urges and craving to use the drug 
  • Spending much time getting, using, and recovering from drug use
  • Failing to keep up with work at home, school, or the office because of drugs
  • Neglecting social or recreational activities because of drug use
  • Repeatedly using the drug, even when it leads to danger
  • Tolerance (need more of the drug to produce the same effects)
  • Continuing to use the drug, even in the presence of physical or mental health disabilities caused or exacerbated by the drug 
  • Presence of withdrawal symptoms which are relieved by drug use

The presence of two or three of these symptoms indicates a mild case of substance use disorder, while four to five symptoms are considered moderate. A person with six or more will be diagnosed with severe substance use disorders. 

You can contact the Canadian Center for Addiction at 1-855-499-9446 for support and counseling if you or a loved one is struggling with substance use disorders.

How Addiction and Mental Illness Are Connected 

Substance use disorder is a mental disorder that affects an individual’s brain and behavior, making them unable to control their use of substances like pills, alcohol and other drugs. This condition causes physical changes in the brain leading to loss of impulse control over repeated substance use. 

To understand the connection between mental illness and addiction and why people do drugs, it’s necessary to define co-occurring mental illness. A co-occurring disorder is a situation where a person has two or more mental disorders or medical illnesses at the same time. 

About half of the people who struggle with addiction will have a co-occurring mental illness at some point. While substance dependence and mental health disorder occur together, it is not certain whether one necessarily affects the other. However, possible reasons addiction and mental health issues co-occur frequently include the following: 

They have similar risk factors 

Addiction and mental illness have similar risk factors like genetics, environmental conditions, such as stress, and traumatic experiences. 

Mental conditions contribute to addictions

People with mental illnesses and health disorders tend to self-medicate or overuse prescription increasing their risk of becoming addicted. 

Addictions can also contribute to mental disorders

Repeated substance use due to addiction can affect the brain’s structure, leading to depression and other mental disorders. 

How Addiction Affects and Changes the Brain

Brain damage from drugs occurs due to their ability to alter the brain structure permanently. Addiction changes the brain’s natural balance, communication patterns, and chemistry. Brain changes from addiction depend on the type and frequency of drugs used and how long the person has been addicted. 

The human brain has a reward system that is developed to reinforce behaviors required for survival, such as eating. Eating triggers the reward pathway to activate dopamine, a pleasure chemical in the brain that leaves you satisfied and makes you desire to eat again in the future. 

Addiction alters the brain's response to addictive substances like food, i.e., it makes the brain think it needs the substance for survival. This change occurs because addictive substances flood the brain with higher amounts of dopamine, leaving the user with an intensely pleasurable feeling. The brain remembers this pleasure and associates it with the substance. 

With continued use, the brain also adapts to the dopamine released and needs more of the substance to get the same pleasure (tolerance). The individual will eventually develop substance dependence – a situation where they cannot function without the substance and need it just to feel normal. If they suddenly stop using the substance, they may experience mild to severe withdrawal symptoms, which may require medical intervention. Addiction may also cause problems with learning, memory, attention, and decision-making.

The Way Society Sees Addiction 

Addiction is still regarded by many in society as a sign of a moral failure or lack of willpower. Stigmatic descriptions like “junkie,” “head,” and “druggie,” which are widely used socially, create significant barriers to getting treatment. Addiction stigma persists despite advances in tackling addiction as a disease, making addicts more reluctant to seek treatment.

Addiction affects people from all walks of life and is not necessarily the result of bad decisions. Society’s disdain for addiction is also reinforced by the socially unacceptable behaviors that addicts may exhibit – lying, stealing, irresponsibility, and recklessness. However, we must understand that addicts are victims of disease, and our contempt is more likely to isolate and push the addict on an endless downward spiral than help them. 

Addiction is a disease, and no one will choose to be addicted any more than they will choose to have diabetes or cancer. Like other terminal diseases, it can get worse and become fatal if untreated. But with the right approach and treatment, an addict can and will recover from their disease. You can get addiction help for yourself or your loved one by calling calling 1-855-499-9446 or request a call.

The Different Types of Addiction

Substance abuse comes to the mind of most people when they think of addiction. However, addiction covers the compulsive use of substances and engagement in unwanted behavior. The most common types of addictions include: 

Alcohol addiction

Alcohol use is legal and socially acceptable in most places. It is widely available, and its acceptability often makes it difficult to distinguish between safe use and abuse. Alcohol drug addiction manifests when drinking begins to take priority over work, studies, relationships, and other important aspects of a person’s life. 

Alcohol addiction is a medical condition and can have severe consequences. It is associated with depression, brain damage, accidents, liver problems, reckless behavior, and suicide. Treatment of alcohol drug addiction may include medications, behavioral therapy, and support. 

Tobacco or Nicotine Addiction

Nicotine is the addictive component of tobacco products (cigars, cigarettes, and vaping devices). Tobacco products are chewed or inhaled. Nicotine is highly addictive, and tobacco products are linked to cancers and heart diseases. It is also widely available, and people who start using nicotine as teens struggle to quit. Nicotine addiction is treated using medications, therapy, and support groups. 

Drug addiction 

Drug addiction is a brain disease that makes a person unable to stop using a drug despite its harmful effects. A person can abuse and become addicted to illegal drugs (cocaine, heroin, methamphetamines) or prescription drugs (opioids, benzodiazepines, and barbiturates). 

Drug addiction affects every aspect of a person’s life and can be fatal if not treated. Treatment modalities for drug addiction depend on the drug type, severity of substance dependence, and individual factors.

Gambling Addiction

A person with a gambling addiction has an uncontrollable urge to visit casinos, bet on sports, buy lottery tickets, play slot machines, or gamble online. Gambling addiction can affect an individual’s finances and relationships. Treatment of gambling addiction involves psychotherapy, 12-step programs, rehabilitation, lifestyle changes, and medications in cases of an underlying mental disorder. 

Sex addiction

There is considerable debate on whether sex addiction is a mental health disorder. The condition has been removed from the DSM-5 as experts cannot agree on what criteria constitute an addiction. However, compulsive sexual behavior can strain relationships and lead to reckless behavior. 12-step programs, behavioral therapy, and specialized recovery programs may be used to treat sex addiction. 

Shopping Addiction

Shopping addiction is also known as compulsive buying disorder and describes a compulsion to spend money regardless of need or financial capacity. Experts also debate the legitimacy of this disorder, and it is not listed in the DSM-5. People with a shopping addiction may compulsively buy specific products like jewelry or gadgets or anything from clothes to food and stocks. People with this disorder get the same euphoria from buying items as someone who uses other drugs to get high. 

Treating shopping disorders is challenging as a person may need to buy items for everyday use. Behavioral therapy and counseling are often used to manage the condition, and the person may also need to be cut from their cash flow. Money management classes and 12-step programs – Shopaholics Anonymous – may also be included as part of therapy.

Video game Addiction

Video game addiction is a condition in which an individual has reduced control over their electronic or Internet gaming habits. A person with this condition may prioritize gaming over all other activities and interests. 

Studies about video game disorder are in their nascent stages, and there is controversy over the legitimacy of the condition. Cognitive behavioral therapy may help people with gaming problems modify their thoughts about playing games to change their behavior. Parents of young people with video game addiction may also have to set and enforce limits on their kid’s playing time. 

Internet and Social Media Addiction

The Internet and social media have soared in popularity in the past few years. People connect with friends and share important moments on their feeds. However, excessive Internet and social media use can affect the brain negatively and become an addiction. You know you have a problem with the Internet and Social media if its use negatively affects other parts of your life or you’re using it to cope with real problems.

Social media addiction is not recognized as an official diagnosis, but the brain releases dopamine signals whenever we log on to our favorite apps. If your use of the Internet and social media is becoming a problem, you may need to speak to a mental health professional for advice. It also helps to consciously set healthy boundaries to regulate social media use before it becomes a serious problem.

Why are some at a Greater Risk of Addiction Than Others?

Everyone can potentially develop an addiction, but certain factors put some individuals at greater risk than others. They include:

Genetic Factors

Multiple genetic factors are thought to play a role in addiction, with gene variation accounting for 40% to 60% of an individual’s addiction risk. A person’s DNA composition does not necessarily mean that they will become an addict. People with a genetic predisposition to an addiction still have to abuse a substance repeatedly before addiction can occur.

Mental Health Problems

Mental health disorders can also contribute to an individual’s addiction risk. Mental conditions that frequently co-occur with substance abuse or addiction include: 

  • Bipolar disorder
  • Attention deficit hyperactivity disorder (ADHD)
  • Post-traumatic stress disorder
  • Schizophrenia
  • Anxiety disorders 
  • Depression 

Individuals with these conditions may start self-medicating with alcohol or drugs. While they may temporarily help with symptoms, they worsen symptoms over time and cause brain changes that reinforce addictive behavior. 

Environmental Factors

Environmental and social influences may also put a person at greater risk of becoming addicted. Some of these factors include: 

  • Absence of parental supervision
  • Family members who abuse drugs
  • Poverty
  • Peer pressure and drug experimentation
  • Low-self esteem
  • Poor academic performance


People can become addicted to substances at any age, but drug use for most people starts during their teenage years, which is also the period when most mental health disabilities begin to occur. The brain undergoes significant changes during adolescence, which can enhance vulnerability to drug use and addiction. So a person is more likely to become addicted if they start experimenting with substances as teenagers. 

How a person tries a substance may also be a factor in addiction. Smoking or injecting drugs produces a faster high, which wears off quickly, making the user want to try it again. 

How to Recognize the Signs of Addiction 

People with an addiction tend to hide their behavior for as long as they can. But drug addiction cannot be concealed for long as the signs are often dramatic and come on fast. Recognizing addiction signs is not only a doctor’s job; friends and family are the first line of attack against an advancing drug problem. 

Some signs that may point to addiction in an individual include: 

  • Spending more time using a substance, alcohol, or engaging in an addictive activity
  • Lying about their whereabouts or what they’ve been up to during the day.
  • Neglecting relationships or becoming distant from those close to them
  • Diminished interest in the hobbies or activities they previously enjoyed
  • Change in sleeping patterns that results in chronic fatigue
  • Constant complaints of illness 
  • Glazed, bloodshot eyes
  • Unexplained injuries
  • Memory loss or difficulty recalling events
  • Irritable and aggressive behavior
  • Mood swings
  • Sudden changes in weight
  • Reckless behavior without regard for consequences
  • Depression and other mental disorders
  • Suicidal thoughts

Treatment Options for Addiction

Treatment options for addiction vary based on individual needs and the severity of the addiction. The most effective addiction treatments are comprehensive, usually including steps that offer the best chance of recovery and relapse avoidance. 


Detoxification is a medical process that helps to get every trace of the addictive substance out of the addict’s system in a safe environment. Detox helps to avoid the unpleasant and life-threatening withdrawal symptoms that may come with abrupt cessation of substance use. 

Inpatient Treatment

Inpatient treatment is an intensive form of drug addiction treatment that requires living at a treatment facility while receiving treatment, including therapy, support, and constant monitoring by a team of professionals. 

Outpatient Treatment

In outpatient addiction treatment, the patient lives at home and regularly visits an outpatient clinic for counseling and other forms of therapy. Outpatient treatment may also involve staying in a sober living home until the recovering addict can live independently. 

12-Step Programs

A 12-step program is often included in an addiction treatment plan. It is a form of group therapy that aims to allow the addict to recognize the social, spiritual, physical, and spiritual effects of their disease. These programs take advantage of the social reinforcement provided by peer discussion that helps encourage drug-free living. Examples of 12-step programs are Alcoholics Anonymous (AA), Narcotics Anonymous (NA), and Gambler’s Anonymous (GA).

Behavioral Therapy

Behavioral therapy employs individual and group sessions to help addicts acquire the skills required to face triggers without giving in to their cravings. Addicts learn to recognize and deal with unhealthy behavioral patterns and develop the necessary coping skills for staying sober. Examples of behavioral therapy for addicts include Cognitive Behavioral Therapy (CBT) and Rational Emotive Behavioral Therapy (REBT). 


When combined with behavioral therapy, medications can help improve mood and reduce cravings for substances or addictive behavior. Drugs like Acamprosate reduce cravings for alcohol, while Lofexidine can help with symptoms associated with opioid withdrawal.

Getting Help for Your Addiction

Dealing with addiction is tough, and you need all the help you can get to break free completely. Like other diseases, you need professional intervention to overcome addiction successfully. Addiction treatment is usually holistic and aims to equip patients with coping skills to deal with cravings and prevent a relapse.

Most people who go for addiction treatment suffer relapse. However, a relapse should never be seen as a failure but as a temporary blip on the journey to complete recovery. 

The Canadian Center for Addictions helps people understand addictions and the healthier coping strategies available by engaging them in one-on-one counseling with certified counselors, psychiatrists, and mental health professionals. 

Drug addiction is a mental health issue and not a type of weakness. Willpower or a decision to stop being addicted will never be enough. The stigma associated with addiction can also make talking about mental health issues embarrassing. However, addiction is destructive, and the best course of action is to seek professional help immediately. Addiction treatment works, and early intervention sets you quickly on the path to recovery. Call 1-855-499-9446 or request a call for addiction help for you or a loved one today.


What links drug addiction and mental illness?

Drug addiction is a mental illness because it changes brain structure and behaviour, leading to compulsive drug use. The DSM-5 classifies drug use disorders as mental illnesses.

How does drug addiction change the brain?

Drug addiction alters the brain's balance and communication patterns, impairing learning, memory, focus, and decision-making.

Can addiction and mental illness occur together?

Yes, they often co-occur. Shared risk factors like genetics and environment contribute to both, and one can worsen the other.

Why are some people more likely to become addicted?

Genetics, mental health conditions, environment, and age affect addiction risk. Factors like peer pressure and early substance use also play a role.

What are the treatment options for drug addiction?

Treatment includes detox, inpatient and outpatient programs, 12-step groups, therapy, and medications. Contact the Canadian Center for Addiction at 1-855-499-9446 for support.

Certified Addiction Counsellor

Seth brings many years of professional experience working the front lines of addiction in both the government and privatized sectors.

Dr. Victoria Perez Gonzalez is a highly respected doctor who specializes in the brain and mental health. She has extensive knowledge and experience in this field.

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