Drug Dependence

Compulsive use of drugs, producing withdrawal symptoms when stopped

  • Usually develops in adolescence
  • More common in males
  • Genetics may be a significant factor
  • Stress, social factors, and peer pressure are risk factors

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 (see Drugs and health).

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 (see Sleeping drugs) and painkillers. Two common types of dependence are nicotine dependence (see Tobacco and health) and alcohol dependence. Nicotine dependence rarely affects work and social life, but alcohol dependence is often damaging. Drug addictions may lead to debt, loss of work, and breakdown in close relationships.

What are the causes?

Initially, drugs may be taken for the psychological “high” they produce and because they relieve symptoms such as anxiety (see Anxiety disorders) and insomnia. People who find it difficult to cope with stress may be more susceptible, as may people who have a parent who has abused drugs or alcohol. There is also some evidence that genetic factors may play a role in a person’s susceptibility to drug dependence.

Dependence is more common in males than females, and peer pressure in adolescence and readily available illegal drugs make young people particularly vulnerable. The risk of dependence developing depends on which drug is taken. For example, heroin may cause dependence after only a few doses.

What are the symptoms?

There are different symptoms for each drug. However, certain areas of behaviour tend to be altered by most drugs that cause dependence. Symptoms of drug dependence 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 diseases such as HIV infection (see HIV infection and AIDS) and hepatitis B and C (see Acute hepatitis). Drug dependence often leads to depression.

Needle tracks from drug injections

When a drug-dependent person repeatedly injects drugs, the veins can be damaged. In this picture, the damage is visible as needle tracks on the inside of the arm.

What might be done?

People who are dependent on drugs may not accept that they need help, and a member of their family or a friend may consult a doctor on their behalf. The doctor will ask which drugs are used and about the length and pattern of use.

Once a person has accepted that he or she needs treatment, withdrawal from the drug can begin. If the symptoms of withdrawal are likely to be severe or if there have been failed attempts in the past, admission to hospital or a drug rehabilitation centre will be arranged. Otherwise, withdrawal may be closely supervised at home. Withdrawal symptoms are usually treated with substitute drugs that are less likely to cause dependence. For example, methadone may be used to replace or treat the symptoms of withdrawal from heroin. The doctor will offer support and specialized drug services for long-term counselling.

What is the prognosis?

Treatment of drug dependence is difficult and often unsuccessful. Sometimes there are several withdrawal attempts before dependence is overcome. Success is most likely if the person is strongly motivated and has good support from family, friends, and counselling services. Joining a support group also increases the chance of overcoming dependence

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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