Substance Abuse or Chemical Dependence

What is substance abuse or dependence?

Substance abuse (alcohol or other drugs)

Substance abuse is a recognized health disorder. It refers to the abuse of illegal or legal substances. Alcohol is the most common legal drug of abuse. Substance abuse causes serious problems at work, school, in relationships, and with the law.

Substances that are often abused include:

  • Alcohol
  • Marijuana
  • Tobacco
  • Prescription drugs, such as pain pills, stimulants, or anxiety pills 
  • Methamphetamine  
  • Cocaine
  • Opiates
  • Anabolic steroids
  • Hallucinogens 
  • Inhalants

Substance (drug) dependence

Substance dependence describes abuse of drugs or alcohol that continues, even when serious problems related to their use have developed. Signs of dependence include:

  • You need more of the drug to get an effect.
  • You have withdrawal symptoms if you decrease or stop using the drug.
  • You spend a lot of time getting, using, and recovering from the effects of using drugs.
  • You withdraw from social and recreational activities.
  • You keep using the drug even though you are aware of the physical, psychological, and family or social problems that are caused by your ongoing abuse.


What causes substance abuse or dependence?

The cause of substance abuse and dependence is unclear. It probably involves a mix of genetics, environment and emotional factors. However, while the first use of drugs or alcohol is voluntary, continued use quickly changes how the brain feels pleasure. Using drugs repeatedly changes the structure of the brain so that a person no longer has control. Substance abuse is a disease that results in the compulsive need for the drug.

What are the symptoms of substance abuse or dependence?

The following are the most common behaviors that signal you have a problem with drug or alcohol abuse:

  • You get high on drugs or get drunk on a regular basis
  • You lie, especially about how much you are using or drinking
  • You avoid friends and family members
  • You have given up activities you used to enjoy, such as sports or spending time with non-using friends
  • You talk or think a lot about using drugs or alcohol
  • You believe you need to use or drink to have fun
  • You pressure others to use or drink
  • You get in trouble with the law
  • You take risks, such as sexual risks or driving under the influence of a substance
  • Your work performance suffers due to substance abuse before, after, or during working or business hours
  • You miss work due to substance use
  • You feel depressed, hopeless, or suicidal feelings

The symptoms of drug or alcohol abuse may look like other medical problems or mental health conditions. Always consult your health care provider for a diagnosis.

How is substance abuse or dependence diagnosed?

A family doctor, health care provider, psychiatrist, or qualified mental health professional can diagnose substance abuse. Depending on the substance abused, the frequency of use, and the length of time since last used, your doctor may note the following:

  • Weight loss
  • Constant fatigue
  • Red eyes
  • Little concern for hygiene
  • Unexpected problems in heart rate or blood pressure
  • Depression, anxiety, or sleep problems