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Last Edited: September 12, 2020
Patricia Howard, LMFT, CADC
Clinically Reviewed
Jim Brown, CDCA
All of the information on this page has been reviewd and certified addiction professional.

Physiological & Physical Dependence on Drugs or Alcohol

Drug & Alcohol Dependency

According to the National Institute on Drug Abuse, a dependence on a specific substance occurs when the neurons in the brain adapt to that drug, leading the neurons to only function normally when that drug is in your system. When you stop using a drug that you’ve developed a dependency on, you may experience physiological reactions as your brain tries to adjust to the changes. These withdrawal symptoms can range from being mild and temporary, to long-lasting or even life-threatening.

The NIH makes it clear that abuse and dependency are two distinct conditions, with each having unique signs and symptoms. They say that while abusing drugs or Alcohol can certainly lead to the development of a dependency, the term substance abuse is about the hazardous behaviors and unusual, and often negative, activities that you can engage in while you are actively abusing drugs.

A dependency means that your body or mind actually depends on a particular drug, Alcohol or other substance in order to function in a way that’s become normal for you. This could mean that you will develop uncomfortable physical symptoms if you stop taking the drug; you will experience physiological symptoms like anxiety, depression, or irritability; or you may experience a combination of both physical and psychological withdrawal symptoms.

When you have developed a dependency, you may find that you need to take increasingly larger and more frequent doses to maintain the desired effects while avoiding both physical and physiological withdrawal symptoms. This is one of the reasons why dependency can evolve into a serious addiction, even for people who are taking prescription medications under the care of a medical professional.

Dependency isn’t always about drinking Alcohol or using illicit drugs; you can have a legitimate dependency on a wide range of substances without experiencing any of the typical problems associated with substance abuse and addictions. For example, millions of people with diabetes are completely dependent upon the drug insulin – without it, they will quickly suffer from serious, life-threatening withdrawal symptoms that could result in death. The same is true for many people who rely on anti-seizure medications, blood thinners, and other drugs that are taken on a regular basis to alter how your body functions.

There is a common misconception that being dependent on a drug means that you are addicted, and it’s this misconception that can actually cause some people to conceal the fact that they’ve developed a physical dependency. Many people fear that if they seek help for dependency issues, they’ll be labeled as a drug addict, while the fact is that failing to get help for a dependency can actually lead to more serious problems like drug abuse and drug addiction. Therefore, it’s important to recognize what exactly dependency is; when it’s treated early, you can prevent bigger issues from developing.

Commonly Abused Substances

Addiction vs Physical Dependence

If you’re unclear about the difference between drug addiction and physical dependence on a drug, you’re not alone. Many people have trouble recognizing the fact that addiction to a substance can occur without being physically dependent on that same substance, and that there are many distinct differences in the signs and symptoms of both addiction and physical dependency.

Physical dependence on a substance means that the way your body functions has been temporarily altered by the substance, and you are likely to experience physical and physiological withdrawal symptoms when you quit that substance. The chances of your body building up a tolerance to a drug increase over time – the longer you use a drug the longer and more severe, your withdrawal symptoms will be.

According to the American Society of Addiction Medicine, a person who has developed a physical dependence on Opioids for pain management might continue to use the Opioids even once they are no longer experiencing severe pain. In this case, the patient isn’t necessarily addicted to the Opioids; they may simply want to avoid the uncomfortable physical symptoms that could emerge as they withdraw from the drugs. However, if they start to develop unhealthy behaviors in order to seek out more Opioids, they may also be diagnosed as having an addiction.

You can become physically dependent on a wide range of substances, including nicotine, sugar, and caffeine, but that doesn’t mean you’re addicted. If you usually drink four or five cups of coffee daily then suddenly decide to quit drinking coffee, chances are good you’ll experience mild withdrawal symptoms, such as a headache, nausea, and difficulty concentrating; these symptoms will disappear when you either decide to drink coffee again, or wait until your body is no longer dependent on the caffeine and other chemicals in coffee.

In most cases, physical dependence on any substance is easy to manage with prescription medications or a controlled period of slowing tapering down your intake.

On the other hand, addiction is classified as a chronic disease that can be treated, but not actually cured. According to the American Psychiatric Association, addiction in a complex brain disease that is manifested by uncontrollable cravings, obsessive behaviors, and an inability to self-regulate abuse of a harmful substance in spite of serious, and often life-threatening, consequences.

People who suffer from addiction experience changes to the biology of their brains, which lead to the development of distorted thinking and altered body functioning.

Unlike physical dependence, addiction cannot be treated using prescription medications or detox alone, although medically-supervised withdrawal can be a part of addiction treatment. Treating addiction is a life-long process that involves replacing addictive, dysfunctional behaviors and distorted thought patterns with healthy behaviors and non-destructive coping mechanisms.

The CDC estimates that up to 18 women die in the United States every day from an overdose of opioid drugs, many of which were obtained through a prescription.

Psychological vs Physical Dependence

While the term dependence is often used to describe a collection of symptoms experienced by someone who uses drugs or Alcohol, there are actually two distinct types of dependency – psychological, and physical.

Physical dependence refers to how the body has adapted to rely on the intake of external stimulants, depressants, or other chemicals to maintain a specific balance or equilibrium. When that balance is interrupted by the reduction or complete withdrawal, physical withdrawal symptoms can emerge.

In most cases, these symptoms will last anywhere from a few hours to a few days, and they can usually be well-managed with medical and alternative therapies. If you have become physically dependent upon a drug that causes significant changes to the chemistry of your body, you may need to detox under close medical supervision. Withdrawing from some drugs can lead to serious, and even life-threatening changes in your blood pressure, respiration rate and heart rate; vomiting, diarrhea, and seizures can occur when you quit using a drug that you are physically dependent on.

By comparison, a psychological dependence can be very difficult to treat. Also known as a mental dependence, this occurs when your desire to drink Alcohol, use drugs, or take a specific substance becomes a conditioned response to a particular feeling, location, person, memory, or event. These are known as triggers, and they are unique to every person – your particular triggers are specific to you.

Contrary to popular belief, triggers are more than simple habits or patterns of behavior – triggers related to a specific, addictive substance actually set off a complex combination of biochemical changes within the brain, and these powerful influences can drive you to drink or use drugs. The stronger your triggers are, the more difficult it will be to overcome your psychological dependence.

Unlike physical dependence, which can be relatively easily managed using medication, medical monitoring, and alternative therapies like massage, acupuncture, and meditation, managing the powerful symptoms of psychological dependence is exceptionally challenging. There’s no easy way to overcome a psychological dependency, however, it is possible.

Treatment centers and rehab facilities focus on helping addicted people understand their psychological dependency issues through both one-on-one and group therapy sessions. During treatment, you spend a significant amount of time learning to identify your own personal triggers, as well as developing healthy, drug-free coping strategies and tools that you can use when you are confronted with one of your triggers.

Over time, most addicted people find that their triggers become less powerful, and many people in recovery even discover that the longer they are sober, the fewer triggers they have. People who are successful in staying clean and sober tend to be very aware of what their triggers are, and they are always working on healthy, drug-free ways to manage their stress levels.

According to SAMHSA (Substance Abuse and Mental Health Services Administration), in 2014, almost 8 million American adults battled both a mental health disorder and a substance use disorder, or co-occurring disorders.

The Addicted Brain and Disease Model

In the past, people who had substance abuse issues were often viewed as being morally bankrupt and having no self-control; this perception made it exceptionally difficult for addicts to get the help they needed to manage their disease.

With the launch of Alcoholics Anonymous and the publication of The Big Book in 1939, medical professionals started viewing Alcoholism and drug addiction as a chronic disease that required ongoing treatment. This helped pave the way for researchers, doctors and addiction specialists, who have now come to understand that addiction is actually a brain disease – a disease that can be linked to physical changes in how the brain works, which in turn fuels the addictive behaviors and self-destructive actions that are linked to substance abuse.

Also known as the biomedical model of addiction, the disease model demonstrates that addiction isn’t a moral issue or a weakness of character – it’s a complex medical condition caused by a variety of genetic and environmental factors. Researchers have now used advanced imaging technology to demonstrate that what Bill W. and the founding members of AA said in 1939 is true – substance abuse is truly a brain disease.

Neurosciences experts have discovered that the brains of people who suffer from Alcoholism or drug addiction have notable differences when compared to non-drug users. People with substance abuse problems often have specific, hereditary traits that impact how they respond to a stimulus like drugs or Alcohol; they also tend to have fewer dopamine receptors in their brains. This means that people with addiction issues actually need to use drugs to trigger the release of dopamine, which explains why some people are predisposed to suffering from substance abuse.

The vast majority of medical professionals now subscribe to the biomedical model of addiction – doctors now understand that people who abuse drugs or Alcohol need ongoing support and treatment using a variety of methods, including pharmaceutical support and cognitive behavior therapy.

For the most part, insurance companies have also embraced the disease model of addiction – that’s why most insurance providers now offer either partial or full coverage for detox and treatment facilities. Insurance companies recognize the fact that addiction is a serious, and costly, health issue that when left untreated, can lead to major expenses down the road. From a sheer cost perspective, it’s actually cheaper for insurance providers to fund treatment programs than it is for them to cover the expenses generated by an addicted person who continues to drink or use drugs.

Stigmatizing people who struggle with substance abuse issues tend to create barriers for those who need help the most; it actually makes the overall problem worse and can make it exceptionally difficult for addicted people to deal with their issues. This is why the disease model is widely embraced among addiction experts and the recovery community; recognizing the fact that addiction is actually a severe, chronic illness has opened the doors for millions of addicted people who need the support of medical professionals, addiction experts, and other addicts to achieve, and maintain, their sobriety.

Abusing drugs or alcohol before the brain is fully developed, anytime before a person’s mid-20s, may increase the risk for addiction later in life due to the changes these substances make to growing brains.

Substance Abuse, Use and Dependency

Substance use, abuse, and dependence are often confused with each other, and some people make the mistake of using these three terms interchangeably. When these words are used in relation to addictions, they actually refer to three specific, unique conditions that are related, but independent of one another.

Substance use simply means consuming or ingesting a drug or Alcohol. Anyone who has ever taken an aspirin, sipped on a glass of wine, or used a prescription medication could be called a substance user. Many people are able to indulge in occasional, recreational substance abuse, such as having a beer, while maintaining a healthy, addiction-free lifestyle.

What is important to understand is that substance use can be the first step toward developing a problem with drugs or Alcohol – the fact is that if you never use a substance, you’ll never abuse it, or become dependent upon it. The vast majority of addicted people can clearly remember exactly when they took their first drink, or got high for the first time.

People who regularly use addictive substances like Opioids, Cocaine, Benzodiazepines, and Alcohol may begin to abuse these drugs – in some cases, this abuse starts soon after they take their very first dose, while for others, their abuse develops over a period of weeks, months, or even years. Substance abuse is often related to a specific trigger, such as a traumatic event, or exceptionally stressful period in your life. For example, many Alcoholics started out as social drinkers who did not abuse Alcohol, however, when faced with a difficult series of events in their life, they began to drink more Alcohol, more frequently, and this led to their abuse.

Substance abuse is characterized by changes in your behavior, interests, and personality – you might lose interest in your usual hobbies, sports, or relationships; start having trouble at home, work, or school; or even engage in risky or illegal activities in order to score your drugs. A person who is actively abusing one or more substances might miss work because they are intoxicated, get into an automobile accident as a result of being impaired, or even break up with their partner or spouse over their addictive behaviors.

When a people who have substance abuse issues develop a tolerance for their drug of choice, they have become physically and physiologically dependent – this is also known as having an addiction. They need professional help to deal with the effects that drugs and Alcohol have had on their body and brain, and they will require intensive treatment and lifelong monitoring to recover from their substance abuse and dependency issues.