A substance use problem is a medical condition. It is substance use that:
It can also involve using or taking a substance in increasing amounts, going to great lengths to obtain the substance, experiencing withdrawal symptoms when the substance is stopped, or being unable to stop or reduce the use of the substance.
Depressants (e.g., alcohol, barbiturates, benzodiazepines), stimulants (e.g., amphetamines, cocaine, MDMA, or ecstasy), hallucinogenics (e.g., LSD), and opioids (e.g., codeine, heroin, and morphine) are the most commonly abused substances. Anabolic steroids are sometimes abused in order to improve athletic performance.
Substance use problems are very complex medical problems. Because they affect the brain, they are not just about willpower. Since there is a lot of stigma (shameful feelings) associated with substance abuse problems, health care professionals are not using terms such as "addiction," "addict," and "drug abuse" as much. Instead, they are using "substance use problems" and "people with substance use problems."
Almost all substances associated with substance use problems affect the "reward mechanism" in the brain. The main chemical messenger involved in the brain's reward mechanism is dopamine. Each time the person uses the substance they feel good, which makes them want to use the substance again. Over time, changes in the brain occur (e.g., less dopamine is produced), which lessens the pleasurable effects of the substance and larger amounts are needed to get the same feeling.
The causes of substance use problems aren't clear, although there are many factors that are thought to play a role. Heredity (genetics) appears to be involved, as the risk of substance use problems is higher for people with family members with these problems. A person's environment, such as school, work, friends, family, and cultural and religious beliefs, can also affect substance use problems.
Other mental health conditions such as anxiety and depression may also play a role. Substance use may also start when people try to manage unpleasant feelings and emotions (e.g., anger, stress, sadness). People who are subject to discrimination may also be at risk for substance use problems.
With substance use problems, people become dependent on the substance physically, psychologically, or both.
Physical dependence involves becoming tolerant to a substance. This means that more of the drug or substance is needed to obtain the same effect. When people stop taking the substance, they suffer withdrawal symptoms that can include shaking, headaches, and diarrhea. Drug withdrawal can even be life-threatening. Mental or psychological problems such as depression and anxiety can also occur during drug withdrawal.
Some people can be physically dependent on a substance without being psychologically dependent on it, especially when a medication is being used for a valid medical condition.
Psychological dependence involves feeling that a substance is needed to feel good and function. With psychological dependence, people often crave the substance and will go to great lengths to acquire the substance to fulfill their craving. Substances that cause psychological dependence usually act on the brain and have one or more of the following effects:
There are many complications to substance use problems. They can cause physical problems such as liver disease, lung disease, heart disease, vitamin deficiencies, and brain damage. Some substances can cause birth defects and others can damage the immune system, increasing the risk of infections.
People using amphetamines can suffer from heart attacks, strokes, severe anxiety, and paranoia. Hallucinogens, because they distort reality, can make people temporarily psychotic or make them try things they can't realistically do, like flying. Conditions such as AIDS or hepatitis transmitted through shared, dirty needles are another possible complication. Overdoses of certain substances can even lead to death.
Other complications of substance use problems include social consequences such as damage to work, family, and personal relationships. Those who neglect their families create social problems for their spouses and children. They may commit criminal acts such as stealing to support their substance use problem. If they drive while under the influence of substances, death or injury to themselves or others can result. Some substances can alter the perception of reality and make people apathetic about work or school. If a woman with a substance use problem is pregnant, she may make her fetus physically dependent on the substance she's using.