What Is Substance Use Disorder (SUD)?

Substance Use Disorder (SUD), also known as “addiction” or “dependence,” is a chronic but treatable mental health condition characterized by an alteration in behavior and thinking patterns that may cause a person to lose control of their ability to limit their intake of certain substances. In 2022, nearly 50 million people aged 12 and older had had a SUD in the past year. SUD can have profound effects on both the person with the SUD and those close to them.

Substances Associated with SUD

There are currently 10 separate classes of substances associated with SUD recognized by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

• Alcohol
• Caffeine
• Cannabis
• Hallucinogens (e.g., phencyclidine/PCP, dextromethorphan/DXM, MDMA/ecstasy)
• Inhalants (e.g., solvents, aerosols, “poppers”)
• Opioids (e.g., heroin, oxycodone, fentanyl, other prescription pain medications)
• Sedatives/Hypnotics/Anxiolytics (e.g., benzodiazepines, barbiturates, other sleep and anxiety medications)
• Stimulants (e.g., cocaine, methamphetamine, ADHD medications)
• Tobacco (e.g., cigarettes, cigars, snuff, chewing tobacco)
• Other Substances (e.g., non-tobacco nicotine products, synthetic cannabis/K2, kratom, or anything not categorized above)

Many people with SUD use more than one substance and thus may meet the criteria for more than one class of substance use disorder.

SUD typically involves a pattern of substance-seeking behaviors, intense cravings, and difficulty in controlling or stopping the use despite risks or consequences, including major social or interpersonal problems such as failing to complete work or school commitments. It can be difficult to understand why some people become habitual users of these substances, and the answer is often not even clear to the person with SUD. Here are some of the more commonly reported reasons why people with SUD might start to use substances:

Self-Medication

Some people say that that they started to use a substance to relieve stress or escape their problems, such as grief, loneliness, trauma, physical pain, or other mental health conditions.

Experimentation

Other people report using substances because they are curious about the effects, or see their peers doing it and want to fit in. Although this is known to occur in most age groups, young people are especially vulnerable to pressure from peers. Adolescence is the most common life stage in which to begin using substances.

Inadvertent

People may also develop SUD without realizing that they have become dependent on a substance. For example, some people have developed an SUD related to prescribed medications for pain, anxiety, or other conditions. This often takes the form of starting to take more medicine than prescribed, finishing prescriptions early, or seeking other ways to obtain the medication.

Enhancement

Some substances are touted as being “performance enhancers” in certain areas of life, which can lead people to start using them to improve appearance, promote wakefulness, and enhance energy or cognitive ability. While many of these substances have a medical use when taken as prescribed, they are often obtained without medical oversight.

Recognizing Signs and Symptoms of SUD

If you or someone close to you seems to be losing control over use of a substance, that may indicate a substance use disorder. Recognition of the problem is the first step towards finding the support needed. Reach out to a mental health clinician for help if more than one of the below common symptoms of SUD are present. To locate an appropriate LifeStance clinician near you, browse the provider directory, click “Display Additional Filters,” and select “Treatment Areas,” then “Alcohol and Drug Use Issues” in the drop-down box.

Recognizing SUD In Yourself:

• Feeling strong urges or cravings to take the substance regularly
• Constantly thinking about using and obtaining the substance
• Needing to use more of the substance to achieve the same effect
• Taking the substance daily or multiple times daily
• Difficulty stopping the use despite negative consequences
• Experiencing withdrawal symptoms when the substance is not used

Recognizing SUD In Someone Else:

Recognizing a SUD in someone else can be challenging, as people with SUD may hide or be in denial about their disorder. However, there are certain clues that may indicate the presence of an SUD. The following are signs of an SUD that you might recognize in someone close to you:

• Appearing anxious, paranoid, or fearful without an apparent reason
• Showing an uncharacteristic lack of motivation, such as frequently acting lethargic or “spaced out”
• Having periods of increased energy, or emotional instability
• Sudden mood swings, irritability, or anger/agitation
• Experiencing a change in personality or attitude that is difficult to explain
• Unusual financial strain or borrowing of money, as people with SUD may start to prioritize the obtaining of substances over essential expenses for themselves or their families
• Showing physical signs of SUD such as bloodshot or glazed eyes, dilated or constricted pupils, changes in appetite or weight, unexplained bruises or marks, tremors, slurred speech, or impaired coordination
• Starting to spend time with a new group of friends or isolating themselves from their usual social circle. SUD can lead to changes in social relationships and lead to the formation of new relationships centered around substance use.

Diagnosing SUD (DSM-5 Diagnostic Criteria for Substance Use Disorders)

Substance use disorder (SUD) is diagnosed through a comprehensive evaluation conducted by a qualified healthcare clinician. The diagnostic process typically involves the following steps:

1. The clinician will conduct an initial assessment by asking questions about the individual’s substance use patterns, substance use and medical history, mental health, and any associated symptoms or difficulties. This information helps form an initial impression of the presence and potential severity of SUD.The clinician will draw from one or more recognized resources to properly diagnose SUD. The primary resource is the DSM-5, which describes symptoms based on four main categories:
   • Impaired Control
     • Consuming more of the substance, or consuming it more frequently, than recommended
     • Wanting to cut down or stop use, but being unable to
   • Social Problems
     • Neglecting relationships, failing to fulfill responsibilities
     • Giving up activities due to substances
     • Inability to complete necessary tasks (at home, school, or work)
   • Risky Behavior
     • Using substances in unsafe situations
     • Continuing to use substances despite negative effects
   • Physiological Signs
     • Building a tolerance to a substance and requiring more of it to have the desired effect
     • Experiencing withdrawal symptoms when a substance is not used
2. A physical examination may be performed to assess the individual’s overall health and identify any physical complications that can be associated with SUD. Laboratory testing of blood or urine may be conducted to detect the presence of substances in the body and assess their levels.
3. The clinician will often also conduct a psychological evaluation to screen for co-occurring mental health disorders or psychological factors that are frequently associated with SUD.

What Causes SUD?

SUD is a complex mental health condition, and no one cause has been identified. However, there are certain conditions that are known to predispose people to SUD:

• Co-occurring mental health disorders. Mental health conditions such as depression, anxiety, PTSD, and psychosis can both contribute to, and be worsened by, SUD. Some people who struggle with other mental health disorders may attempt to mask their symptoms through consumption of drugs and alcohol.
• Biological factors. Genetic predispositions, differences in brain structure or chemistry, and/or individual variability in metabolism and response to substances can all increase a person’s vulnerability to SUD.
• Peer pressure. Particularly for young people, peer pressure remains a common cause of substance use, which may turn into SUD. This is also true for many adults, who report using substances to match the social or performance norms of their peers.
• Early exposure to drugs. Adolescents who have been exposed to drugs at an early age are particularly vulnerable to developing a SUD due to factors including ongoing cognitive, social, and emotional development.
• Stressful environment. SUD can also be triggered by chronic or sudden stressors, such as living with another person with SUD, living in an abusive household, experiencing a divorce, or losing a loved one.
• Chronic pain. People living with chronic pain may develop SUD when trying to manage their pain symptoms.

It is important to remember that these conditions do not necessarily lead to SUD. People can live with one or more of the above conditions and not develop a SUD, and people who have never had any of these conditions can still develop a SUD.