Dependence - drugs


Updated July 2006

Drug dependence, or addiction, is the excessive and compulsive use of drugs for their effects on mental state. Often, increasing quantities of the drug are needed to produce the desired effect, and physical symptoms may develop if use stops or is delayed. Some drugs, such as LSD, do not cause this physical addiction, but may cause psychological craving. This section will examine illicit drug use, although some of the further references below will cover issues relating to prescription drug abuse. Please also see medicines management for further information on prescription drugs, self-medication and medication by friends, relatives or carers.

Drugs that may produce dependence include those obtained illegally, such as heroin and cocaine, and drugs that are prescribed by a doctor, such as benzodiazepines and painkillers. There are different symptoms for each drug; however, certain types of behaviour tend to be altered by most drugs that cause dependence.

Symptoms often include:
  • mood changes
  • changes in concentration levels
  • altered energy levels
  • faster or slower speech rate
  • increased or decreased appetite
Typically, withdrawal symptoms develop within 12 hours of last using or taking a drug.
Effects range from mild to extremely severe and may include:
  • anxiety and restlessness
  • overheating and sweating, alternating with chills and shivering
  • confusion and hallucinations
  • muscle aches and abdominal cramps
  • diarrhoea and vomiting
  • seizures
Rarely, withdrawal from opioid drugs, such as heroin, may lead to coma. If drugs are injected, sharing needles may transmit blood-borne viruses such as HIV infection and hepatitis B and C.

Treatment of drug dependence is difficult. Sometimes there are several attempts at withdrawal before dependence is overcome. Success is most likely if the person is strongly motivated and has good support from family, friends, and support services.

Further information:

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