What is a Substance Abuse Disorder?

How is addiction defined?

There are different definitions of addiction. The one we use most at Sequoia MD is that addiction is a chronic, relapsing, remitting disease. However, there are other definitions as well.

For example, SAMHSA (Substance Abuse and Mental Health Services Administration) defines a substance abuse disorder as occurring when “the recurrent use of alcohol and/or drugs causes clinically significant impairment, including health problems, disability, and failure to meet major responsibilities at work, school, or home.”

What is the difference between tolerance, dependence, and addiction?

Tolerance, dependence, and addiction are related but not identical.


Tolerance refers to a person needing increasing amounts a substance (such as alcohol or opiates) to achieve the same effect. For example, when someone does not drink alcohol frequently, they may feel drunk after 2-3 drinks, whereas when someone has been drinking for quite some time, that person may now need 5-6 drinks to achieve the same effect.


Dependence occurs when someone has become accustomed to having the chemical in their body all the time, and the lack of that chemical makes that person feel bad and experience withdrawal symptoms— they are physically dependent. The specific symptoms a person experiences depend on different drugs. Dependence is partially related to frequent use— if someone is using the chemical frequently, dependence will develop for most drugs and alcohol.


Addiction is a complex pattern of behavior involving interactions among brain circuits, genetics, the environment, and an individual’s life experiences. People with addiction use substances or engage in behaviors that become compulsive and continue despite harmful consequences. While most addictions revolve around drugs and alcohol, addiction may also occur towards a behavior, such as gambling or sex.

Another way we think about addiction at Sequoia MD is that a person is engaging in a behavior that they recognize is having adverse consequences, and yet they continue in that behavior. For example, this could be negative consequences from the use of alcohol or drugs, such as financial troubles, development of health risks or problems, problems with the family, alienation of friends, or consequences at work.

What’s the difference between illegal drugs, alcohol, and prescription drugs?

From the perspective of substance use, there is little difference between legal and illegal drugs. Whether the substance use disorder is to legally obtain alcohol, illegally obtained prescription drugs, heroin, or other illegal drugs, the basic patterns of addictive behaviors are similar, and the overall treatment plan is fairly similar.

There are often differences that do matter in terms of the legal status of a compound. For example, if the marijuana plant was grown legally, there is clearly a different risk of being arrested than if it was grown illegally. However, from the perspective of brain function, the legality of the marijuana plan does not make much difference.

Why do some people develop substance use disorders and not others?

There is not one answer to this question, as there are many things that we know contribute to substance abuse. Different people have different risk factors. For example, we know that traumatic events in a person’s life can contribute to the development of a substance use disorder, but not all people with trauma develop a substance use disorder.

Research shows that certain kinds of childhood trauma predispose to the development of substance use disorders. We also know that family history plays a large role— substance abuse is at least in part an inherited condition.

Patients with some mental health disorders, such as bipolar disorder, seem to have higher rates of substance use, but not everyone with a mental health disorder will also struggle with substance use. How the brain responds to certain substances is different in different people.

What is the role of meetings in addiction treatment?

One of the challenges of substance use is that when someone is using drugs or alcohol frequently, isolation becomes a challenge. Most of the other people in a person’s life are also using drugs or alcohol, and there are significant feelings of isolation. The antidote to isolation is community.

For this reason, support groups, such as alcoholics anonymous or narcotics anonymous, can provide a community to people trying to find a way out of substance use. Supportive settings of all kinds (including groups) can help people identify problematic behavior and develop healthy behaviors. Often it is easier to hear this from people who have been there and get it than it is to hear it from a professional or from a family member.

This is not to say that professional addiction treatment help and family therapy do not have a role— they do— but instead to highlight that support from people who have lived with an alcohol use disorder and struggled with other addictive drugs can be uniquely helpful.

There are also meetings and groups for family members of a person struggling with drug addiction. The challenges of having a parent, a son or daughter, a spouse, or a sibling who is used are tremendous, and there are resources available for family members such as al-anon and nar-anon. (link: al-anon, near-anon).

What are common drugs of abuse?

Most chemicals that are both widely available and potentially addictive substances are commonly abused. A substance is generally addictive if it produces pleasurable changes in how we feel, such as euphoria. This includes things like alcohol, opioids (heroin, OxyContin, fentanyl, Norco), benzodiazepines (Xanax, Ativan, Klonopin, or Valium), and stimulants such as methamphetamines or prescription drugs such as Adderall or Ritalin.

Are prescription drugs safe?

Prescription medications all have risks. Remember, all drugs, whether antibiotics or painkillers have risks and benefits. Antibiotics can be lifesavers when used appropriately in the treatment of certain infections, but can also lead to all kinds of problems. The same can be said for opioid painkillers.

The key, when prescribing any medication, is to balance the potential negative effects of the medication against the anticipated benefits. A drug is never really “good” or “bad”; instead, it has benefits and risks.

Medications can have significant negative health effects, or significant health benefits, depending on the person, the dose, the frequency of use, etc. In other words, if a person’s major health concerns were high blood pressure (hypertension) and high cholesterol, we would say that the benefits of treatment of a cholesterol drug (statin) and blood pressure drug (anti-hypertensive) would outweigh the risks.

However, treating someone without those conditions with the same medications would not make sense, and the risks of treatment would outweigh the benefits.

Is the use of alcohol and other drugs all the same?

Substance use disorders occur along a spectrum; for some people, these can occur in a mild form, and for other people occur in a severe form. Generally, one could think about this progressing from infrequent drug use (or occasional drug use) to repeated drug use to drug abuse and addiction. Drinking alcohol does not inevitably lead to alcohol abuse.

There is not usually one moment when someone is suddenly “addicted to drugs,” but instead, it’s a progression, a significant increase in the use of a substance, the progressive use of more drugs that leads to a drug problem. Even then, there are a lot of variabilities, as there are many other factors that can influence the severity of the addiction.

Age also plays a role— young adults’ risk of developing a substance use disorder declines the later in life they start using substances. So, someone whose first use of drugs occurs at age 25 has a lower risk of developing a substance abuse disorder than young adults who start using at age 15, for example.

Part of this is because drugs and alcohol change the brain, and the more brain development has occurred at the time of first exposure, the less likely the development of the brain disease is. Our addiction treatment center in Sacramento is here for you. Contact us today!