Harmful use of drugs is a pattern of drug consumption that is causing damage to health.

The damage may be physical (in cases of infection related to drug use) or mental (episodes of depressive disorder) and is often associated with damage to social functioning: family problems, legal problems or work-related issues.

Symptoms can include:

  • depressed mood
  • nervousness
  • insomnia
  • may produce bizarre, unexplained behaviour

Drug dependence refers to a state in which the drug(s) take on a much higher priority for an individual than other behaviours which once had a greater value or meaning to them.

The drug withdrawal state refers to a group of symptoms occurring upon stopping a drug after its prolonged daily use.

Signs and symptoms

The following signs & symptoms can be present in conjunction with substance abuse:

  • may have depressed mood, nervousness or insomnia
  • might present with a direct request for help to withdraw from, or to stabilize, their drug use
  • might present in a state of intoxication or withdrawal, or with physical complications of their drug use (e.g. abscesses or thromboses)
  • may present with social or legal consequences of their drug use (e.g. debt or prosecution)
  • occasionally, covert drug use may manifest itself as bizarre, unexplained behaviour

Signs of drug withdrawal include the following:

  • opioids:
    • nausea
    • sweating
    • restlessness
    • goose bumps
    • diarrhoea (cold turkey)
    • hallucinations
  • sedatives:
    • anxiety
    • tremors
    • insomnia
    • hallucinations (rare)
  • stimulants (cocaine, crack, amphetamine, ecstasy):
    • depression
    • moodiness
    • irritability


Diagnostic features

  • drug use has caused physical harm (e.g. injuries while intoxicated), psychological harm (e.g. symptoms of mental disorder due to drug use), or has led to harmful social consequences (e.g. loss of job, severe family problems, criminality)
  • habitual, harmful, or chaotic drug use
  • difficulty controlling drug use
  • strong desire to use drugs
  • tolerance (can use large amounts of drugs without appearing intoxicated)
  • withdrawal (e.g. anxiety, tremors or other withdrawal symptoms after stopping use)



Recognizing that you have a problem is the first step on the road to recovery, one that takes tremendous courage and strength. Facing your addiction without minimizing the problem or making excuses can feel frightening and overwhelming, but recovery is within reach. If you're ready to make a change and willing to seek help, you can overcome your addiction and build a satisfying, drug-free life for yourself.

Don't try to go it alone, it's easy to get discouraged and rationalize 'just one more'. Whatever treatment option you choose support is essential. Recovering from drug addiction is much easier when you have people you can lean on for encouragement, comfort, and guidance.

consider the costs and benefits of drug use to yourself and your family and friends

seek professional help and support including having investigations

you have a personal responsibility for change

consider your treatment options such as problem-solving or targeted counselling, to deal with your life problems related to drug use

be aware that drug misuse can be a chronic behavioural disorder, controlling or stopping use may require several attempts,  relapse is common

abstinence should be seen as the long-term goal, harm reduction (especially reducing intravenous drug use) might be a more realistic goal in the short- to medium-term

stopping or reducing drug use can result in psychological, social and physical benefits for you

be aware that using some drugs during pregnancy risks harming the baby

if you are an intravenous drug-user, there is a risk of contracting or transmitting HIV, hepatitis, or other infections carried by body fluids, consider appropriate precautions (e.g. condoms and do not share needles, syringes, spoons, water or any other injecting equipment)

consider strategies to avoid or cope with high-risk situations (e.g. social situations, stressful events)

introduce yourself to self-monitoring procedures (e.g. diary of drug use) and safer drug-use behaviours (e.g. time restrictions, slowing down rate of use)

consider your treatment options for referral to appropriate statutory or voluntary services for increased support, e.g. counselling or rehabilitation

consider what your withdrawal symptoms may be and how to manage them

make specific plans to avoid drug use (e.g. how to respond to friends who still use drugs)

identify family or friends who will support you stopping your drug use


Friends and family

If you're worried about a friend or family member's drug use, it's important to know that help is available. Learning about the nature of drug abuse and addiction (how it develops, what it looks like, and why it can have such a powerful hold) will give you a better understanding of the problem and how to best deal with it.

  • find and join a local support group, or make use of help lines
  • educate yourself about drug misuse and the treatment options available
  • encourage the person to change
  • acknowledge the persons anxieties about changing
  • identify and give credit for any success
  • avoid self-blame, you can support a person with a substance misuse problem and encourage treatment, but you can't force an individual to change
  • encourage the person to seek help and treatment

Military Mental Health Service Contact Details

Phone numbers, fax and email


St. George's Hospital,
Corporation Street,
ST16 3AG