Assessment of Drug Dependence

Authored by , Reviewed by Dr John Cox | Last edited | Meets Patient’s editorial guidelines

This article is for Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Medicines for Drug Dependence article more useful, or one of our other health articles.

Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below.

This article summarises the guidance on the assessment of drug dependence from the drug misuse and dependence guidelines jointly produced by the Department of Health, the Scottish Government, the Welsh Assembly Government and the Northern Ireland Executive. The guidelines were last updated in September 2007[1]. It should be read in conjunction with the separate overview article Drug Misuse and Dependence.

  • Good assessment of a drug misuser requires training and competency in the clinician.
  • An empathetic, non-judgemental approach should be used.
  • The full assessment process may take several consultations. A drug-misusing patient may present at a time of crisis. An exhaustive initial interview may reduce the chance of them engaging in a treatment programme. However, enough information needs to be obtained in the initial consultation to assess the presenting problems safely.
  • Relatives or carers should be involved where appropriate.
  • A multidisciplinary approach to assessment may be needed, as the drug misuser may have associated physical and psychological health problems, social functioning problems (including housing and employment) and/or be involved with the criminal justice system.
  • A written document should be produced that can be used as the basis for discussing care planning, goals and objectives with the patient.
  • There may be a locally agreed shared assessment process/care pathway already in place.
  • Once a full assessment has been carried out, a care or treatment plan can be established.
  • Treating any emergency problem.
  • Confirming the patient is taking drugs (history, examination, drug testing).
  • Assessing the degree of dependence.
  • Identifying physical and mental health problems.
  • Identifying social problems: housing, employment, domestic violence, offending.
  • Assessing risk behaviour.
  • Determining expectations of treatment and desire to change.
  • Determining the need for substitute medication.
  • Assessing competency of young people to consent to treatment and involving those with parental responsibility as appropriate.
  • Assessing any risk to dependent children of drug-misusing parents.
  • In private practice, ensuring the patient is able to pay for treatment by legitimate means.
  • Providing access to sterile injecting equipment and safe needle disposal as needed.
  • Providing testing for hepatitis and HIV.
  • Providing immunisation against hepatitis B.
  • Determining the most appropriate level of expertise to manage the patient. Referral or liaison with specialist services may be needed.
  • Notification of the patient to the relevant national drug monitoring system.


This should include:

  • Types of drugs used.
  • Quantity, frequency and pattern of use.
  • Route of administration.
  • Symptoms of dependence.
  • Source of drug (including preparation).
  • Prescribed medication.
  • Tobacco use.
  • Alcohol use, including quantity, frequency and pattern of use.
  • Alcohol dependence symptoms. 

Drug testing

  • Staff performing drug testing should be competent in taking samples and, if appropriate, in reading results. Laboratory testing must be done in accredited laboratories.
  • Screening tests: these are usually carried out first. They are quick, cheap and easy. They are usually done using immunoassay and can be done in the laboratory or using point of care or dipstick tests. Negative results can be reliably accepted. Positive results usually need confirmation using a confirmatory test.
  • Confirmatory tests: these tend to use gas or liquid chromatography and mass spectrometry. They are slower and more expensive but drugs and their metabolites can be detected. It is the gold standard for drug testing.
  • Urine testing: this is what is usually performed. It can show drug use over recent days and is a non-invasive test. Urine specimens may be adulterated (eg, addition of chemicals, dilution by drinking large volumes of fluid), substituted, or be prone to pre-collection abstinence of drugs that may produce a misleading result. It is only very occasionally necessary to directly observe a urine specimen being given and the patient's informed consent is needed for this.
  • Oral fluid testing: oral fluid is easier to collect but drugs are present in lower concentrations and only very recent drug use over the last 24-48 hours can be detected. However, it is less easy to adulterate.
  • Hair testing: this can show drug use over the past few months. It is poor at detecting very recent use. However, it does not differentiate between continual and sporadic use. It is also more complicated and is only performed in some laboratories.
  • Random intermittent drug screening is likely to be the most practical and cost-effective way to provide reliable information about a person's recent drug use.
  • Written procedures should be in place for the collection and storage of biological samples, their dispatch to a laboratory and the discussion and management of reported results.

Approximate durations of detectability of selected drugs in urine

Drug or its metabolite(s)Duration of detectability
Amfetamines including methylamfetamine and 3,4-methylenedioxy-N-methylamfetamine (MDMA).2 days
  • Ultra short-acting (half-life 2 hours - eg, midazolam).
  • Intermediate-acting (half-life 6-24 hours - eg, temazepam, chlordiazepoxide).
  • Long-acting (half-life 24 hours - eg, diazepam, nitrazepam).

  • 12 hours
  • 2-5 days
  • 7 days or more
Buprenorphine and metabolites.8 days
Cocaine metabolite.2-3 days
Methadone (maintenance dosing).7-9 days (approximate)
Codeine, dihydrocodeine, morphine, dextropropoxyphene
(heroin is detected in urine as the metabolite morphine).
48 hours
  • Single use.
  • Moderate use (three times a week).
  • Heavy use (daily).
  • Chronic heavy use (more than three times a day).

  • 3-4 days
  • 5-6 days
  • 20 days
  • Up to 45 days

Risk assessment should be carried out looking at:

  • Overdose risk.
  • Polydrug and alcohol misuse.
  • Unsafe injecting practices.
  • Unsafe sexual practices.
  • Any risks of self-harm or harm to others.
  • Any risks to dependent children.
    • Ask about children, ages and level of contact.
    • What is the effect of the drug use on the parent's functioning?
    • What is the effect of drug-seeking behaviour on the children - are they left unsupervised, or have contact with unsuitable characters?
    • How is drug use funded - diversion of family income?
    • Does the parent's physical/mental health affect their parenting?
    • Can they provide emotional support to the children?
    • Effect on family routines - eg, getting to school on time?
    • Are there other support networks - family, friends?
    • Are the drugs and paraphernalia being stored safely?
    • Are the parents able to access professional help?

Local child protection procedures should be followed if there is risk of significant harm to children. Advice should be given about access to clean injecting equipment and needle exchanges. Information should be given about reducing the risk of overdose and contracting blood-borne infections.

Issues covered should include:

  • Partners, family and support.
  • Housing.
  • Education.
  • Employment.
  • Domestic violence.
  • Benefits and financial problems.
  • Childcare issues: pregnancy, parenting, child protection.

Questions should be asked around:

  • Arrests, outstanding warrants and charges.
  • Probation.
  • Imprisonment.
  • Violent offences and criminal activity.
  • Fines.
  • Involvement with workers in the criminal justice system - eg, probation officers.

It may not always be the GP to whom the patient first presents. Therefore, the clinician involved should perform a health assessment within their competency and refer to other services as appropriate.


History taking should cover the following:

  • Presenting symptoms and perceptions as to why this consultation is taking place.
  • Past medical history.
  • Psychiatric history and any current symptoms.
  • Drug-related complications: abscesses, venous thromboses, septicaemia, endocarditis, constipation.
  • History of accidental/deliberate overdose.
  • Current or past infection with blood-borne viruses.
  • Cervical screening, menstrual and pregnancy history in women.
  • Sexual health and sexually transmitted infection history and contraceptive use.
  • Oral health.
  • Current prescribed and non-prescribed medication.
  • Allergies and sensitivities.


This should include:

  • Assessment of mental health.
  • Assessment of injection sites if injecting/injected in the past: limbs, groins, etc.
  • Weight and height measurement.
  • Urine testing for diabetes and infection.
  • Blood pressure measurement.
  • General assessment of respiratory, cardiovascular and other systems depending on history/presenting symptoms.


A number of investigations may be appropriate depending on the history, risks, symptoms and physical signs:

  • Testing for hepatitis B and C (including polymerase chain reaction (PCR) for hepatitis C virus RNA).
  • Testing for HIV.
  • Pregnancy testing.
  • Blood tests to assess liver, thyroid and renal function and haematological indices.
  • ECG.
  • Further investigation of cardiovascular, gastrointestinal and respiratory systems as appropriate.

Other considerations

There is also the potential for health promotion measures including:

  • Immunisations for hepatitis B (and possibly hepatitis A).
  • Cervical cancer screening.
  • Safer sex and contraceptive advice.
  • Diet and nutritional advice.

In September 2014, NHS England completed a consultation exercise on the 2007 guidelines and is considering whether they need revising. Their website states that much of the existing guidance remains current. However, there have been significant changes since it was issued - eg: 

  • A more recovery-orientated treatment system.
  • An ageing 'traditional' drug population.
  • Changing patterns of drug use, such as:
    • Fewer people using heroin
    • Fewer people injecting drugs
    • Increasing use of new psychoactive substance, legal highs and image and performance-enhancing drugs
    • Alcohol, smoking and addiction to medicines gaining in attention

Areas which NHS England suggest might benefit from review include:

  • New evidence since last publication.
  • Ways of working.
  • Development in the recovery orientation of drug treatment.
  • How to complement other key documents published since 2007, including the National Institute for Health and Care Excellence (NICE) quality standard advice and the National Treatment Agency for Substance Misuse (NTA) publication 'Medications in Recovery'[2, 3].

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Further reading and references

  1. Drug misuse and dependence UK guidelines on clinical management; Dept of Health (England), the Scottish Government, Welsh Assembly Government and Northern Ireland Executive (2007) - archived content

  2. Quality standard for drug use disorders; NICE, November 2012

  3. Strang J; Medications in Recovery Re-orientating Drug Dependence Treatment, National Treatment Agency for Substance Abuse, 2012

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