Drug addiction is a complex brain disease. It is characterized by drug craving, seeking, and use that can persist even in the face of extremely negative consequences. Drug-seeking may become compulsive in large part as a result of the effects of prolonged drug use on brain functioning and, thus, on behavior. For many people, relapses are possible even after long periods of abstinence.

How quickly can I become addicted to a drug?
There is no easy answer to this. If and how quickly you might become addicted to a drug depends on many factors including the biology of your body. All drugs are potentially harmful and may have life-threatening consequences associated with their abuse. There are also vast differences among individuals in sensitivity to various drugs. While one person may use a drug one or many times and suffer no ill effects, another person may be particularly vulnerable and overdose with first use. There is no way of knowing in advance how someone may react.

How do I know if someone is addicted to drugs?
If a person is compulsively seeking and using a drug despite negative consequences, such as loss of job, debt, physical problems brought on by drug abuse, or family problems, then he or she probably is addicted. Seek professional help to determine if this is the case and, if so, the appropriate treatment.

What are the physical signs of abuse or addiction?
The physical signs of abuse or addiction can vary depending on the person and the drug being abused. For example, someone who abuses marijuana may have a chronic cough or worsening of asthmatic symptoms. Each drug has short-term and long-term physical effects. Stimulants like cocaine increase heart rate and blood pressure, whereas opioids like heroin may slow the heart rate and reduce respiration.

If a pregnant woman abuses drugs, does it affect the fetus?
Many substances including alcohol, nicotine, and other drugs of abuse can have negative effects on the developing fetus because they are transferred to the fetus across the placenta. For example, nicotine has been connected with premature birth and low birth weight as has the use of cocaine.

Whether a baby's health problems, if caused by a drug, will continue as the child grows, is not always known. Research does show that children born to mothers who used marijuana regularly during pregnancy may have trouble concentrating, even when older. Our research continues to produce insights on the effects of drug abuse on the fetus.

Are there effective treatments for drug addiction?
Drug addiction can be effectively treated with behavioral-based therapies and, for addiction to some drugs such as heroin or nicotine, medications. Treatment will vary for each person depending on the type of drug(s) being used, and multiple courses of treatment may be needed to achieve success.

What is detoxification, or "detox"?
Detoxification is the process of allowing the body to rid itself of a drug while managing the symptoms of withdrawal. It is often the first step in a drug treatment program and should be followed by treatment with a behavioral-based therapy and/or a medication, if available. Detox alone with no follow-up is not treatment.

What is withdrawal? How long does it last?
Withdrawal is the variety of symptoms that occur after use of some addictive drugs is reduced or stopped. Length of withdrawal and symptoms vary with the type of drug. For example, physical symptoms of heroin withdrawal may include: restlessness, muscle and bone pain, insomnia, diarrhea, vomiting, and cold flashes. These physical symptoms may last for several days, but the general depression, or dysphoria (opposite of euphoria) that often accompanies heroin withdrawal may last for weeks. In many cases withdrawal can be easily treated with medications to ease the symptoms, but treating withdrawal is not the same as treating addiction.