How Can Tolerance Lead to Addiction?

Substance use disorders, or SUDS, are commonly associated with drug dependence and addiction. Dependence can certainly result in addiction. Many people think of drug dependence as a physical addiction in which the user feels that they need the drug to survive and are addicted to how the specific substance feels in their body. Physical dependence or addiction to drugs or alcohol causes the body to build a tolerance. This means that the body requires larger amounts of the substance to satisfy its cravings. Tolerance, dependence, and addiction are intertwined with substance use disorders, making it critically important to understand the difference between them and how they connect.

Tolerance vs Dependence vs Addiction

While related, tolerance, dependence, and addiction impact the user’s brain and body differently.

Tolerance

Tolerance “happens when a person no longer responds to a drug in the way they did at first. So it takes a higher dose of the drug to achieve the same effect as when the person first used it.” Because tolerance causes people to use more and more drugs to achieve a high, it often can cause them to develop a substance use disorder. A high is caused by increased dopamine and opioid peptide activity in the brain’s reward system after ingesting a substance. When the high wears off, the user experiences a neurochemical reaction that causes the reward function of the brain to settle at below-normal levels. People are then drawn to use the substance again to seek the same high, which is never achieved because tolerance develops.

Dependence

We can diagnose dependence based on whether a user experiences withdrawal after ending drug use. Withdrawal is “a group of physical and mental symptoms that can range from mild (if the drug is caffeine) to life-threatening (such as alcohol or opioids, including heroin and prescription pain relievers).” To avoid withdrawal, the user continues to use drugs and is in active addiction. Drug dependence can happen even if a user is not intentionally abusing the drug. For example, many patients are prescribed medications that they take every day, and over time they can become dependent. When they stop using, they need professional assistance to avoid withdrawal. There are some cases where individuals who are dependent on a drug do not become addicted.

Addiction

The main distinction between tolerance, dependence, and addiction is that addiction is classified as a disease. Tolerance, dependence, and addiction can all develop as a result of using drugs or alcohol on a regular and ritualistic basis. Dependence evolves into addiction when “a person keeps using a drug and can’t stop, despite negative consequences from using the drug.” The National Institute on Drug Abuse (NIDA) defines addiction as a chronic, relapsing disorder characterized by:

• Compulsive drug-seeking
• Continued use despite negative consequences
• Lifelong changes in the brain

How Dependence Leads To Addiction

Research conducted by NIDA has shown that “prolonged drug use causes a chemical change in the brain of the addict that alters the brain’s reward system that prompts compulsive drug-seeking in the face of growing consequences.” Experts explain that when substance use continues despite a negative impact on daily function and when the substance use is no longer rewarding, the user’s behavior is referred to as a “pathological pursuit of rewards.” Addiction forms from dependence as a result of chemical alterations in the reward circuits. The American Society of Addiction Medicine (ASAM) states that the pursuit of rewards becomes pathological when the:

• Reward-seeking becomes compulsive or impulsive
• The behavior stops being pleasurable
• The behavior no longer serves as a coping mechanism and no longer provides relief
• The behavior is no longer a function of choice

The pathological pursuit of rewards in addiction occurs when the user is compelled, despite his or her determination to stop using, to repeat maladaptive behaviors despite the fact that the substance is no longer providing them with any relief and only has negative consequences. In addition to struggling with the compulsions of addiction, the user finds themself in an unavoidable cycle of pain. When we approach addiction with empathy and compassion, it becomes evident that people do not want to be actively addicted.

Seeking Professional Help

Addiction arises when someone continues to use a substance despite the negative consequences. Rarely, a user can depend on a substance and have a high tolerance to it without being addicted. NIDA classifies addiction as both a mental illness and a complex brain disorder, making it imperative to seek professional help to successfully recover.

At Boardwalk Recovery Center, we have a supportive staff composed of certified and credentialed providers who make accurate and comprehensive diagnoses. Please reach out to us if you need help with an addiction or compulsive behavior. We are here to help you in your recovery journey by providing a foundation and safe space to take back control of your behaviors.