Substance abuse is a pattern of repeated use of alcohol, drugs, or both, even though this use causes unpleasant or distressing events in the user's life.

A person has a substance abuse problem if one or more of the following have occurred within the past 12 months.

• Substance use has interfered with the person's ability to meet his or her obligations at home, school, or work. The person may not show up for, have poor performance at, or be fired or expelled from work or school. The person may neglect family members or the home.
• Alcohol, drugs, or both have been used repeatedly in dangerous situations, such as while driving a car or operating machinery.
• The person has incurred legal problems related to substance abuse, such as arrests for driving under the influence (DUI) or disorderly conduct.
• The person continues to use alcohol, drugs, or both, despite social or personal problems caused by or made worse by use of the substance. This includes everything from arguments with a family member about drug use to physical fights with strangers.

Someone who has a substance abuse problem may suffer serious withdrawal symptoms if he or she stops drinking alcohol or using a drug suddenly ("cold turkey"). After dependency develops, it may become very difficult to stop drinking or using a drug without outside help. Medical detoxification may be needed.