Skip to main content

Assessment of drug dependence

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 Drug dependence treatment article more useful, or one of our other health articles.

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 20171 .

General information is contained within the separate overview article Drug Misuse and Dependence.

Continue reading below


  • 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.

Elements of assessment1

  • Treat any emergency or acute problems.

  • Confirm the patient is taking psychoactive substances (based on history, examination and drug testing, and through accessing any relevant additional information from clinical records).

  • Assess the degree of dependence including: types of psychoactive drugs used (including prescribed and over-the-counter medicines and tobacco); quantity and frequency of use, pattern of use, routes of administration (including any injecting); sources of drugs obtained and evidence for harmful use or dependence (including any experience of withdrawal syndromes); types of alcohol consumed, quantity and frequency of use, pattern of use, and whether there is evidence of hazardous drinking (above recommended levels for low-risk drinking), or of harmful or dependent use (including experience of alcohol withdrawal syndrome).

  • Identify physical and mental health problems including current or previous physical complications of drug and alcohol use such as infection with blood-borne viruses or continuing related risky behaviours, liver disease, abscesses, overdoses, enduring severe physical disabilities and sexual health problems; risks related to pregnancy; current or previous psychological problems, such as personality problems and disorders, self-harm, history of abuse or trauma, depression, anxiety and severe psychiatric comorbidity (details of contact with mental health services should be recorded).

  • Identify social problems: housing, employment, domestic violence, offending.

  • Assess risk behaviours including those associated with injecting: for drug-misusing parents or other adults with dependent children, obtaining information on the children and any drug-related risks to which they may be exposed; if risk of significant harm to a young person is found, involving other professionals in line with local child protection requirements and child safeguarding procedures; if risk of significant harm to a vulnerable or at-risk adult person is found, responding professionally and in line with local adult safeguarding procedures.

  • Determine expectations of treatment and desire to change.

  • Determine the need for substitute medication.

  • Assess competency of young people to consent to treatment and involving those with parental responsibility as appropriate.

  • Assess any risk to dependent children of drug-misusing parents.

  • In private practice, ensure the patient is able to pay for treatment by legitimate means.

  • Provide access to sterile injecting equipment and safe needle disposal as needed.

  • Provide testing for hepatitis B and HIV.

  • Provide immunisation against hepatitis B.

  • Determine 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.

Continue reading below

Assessment of current drug and alcohol use


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.

Screening and monitoring tools

Screening, assessment and monitoring tools are sometimes used to support the assessment and review process. They may help standardise assessment and care when used in the context of clear local protocols. Examples of tools used for substance use include:

  • The Alcohol Use Disorders Identification Tests (AUDIT or AUDIT-C) for screening for risky or dependent alcohol use.

  • The Severity of Alcohol Dependence Questionnaire (SADQ) for assessing severity of alcohol dependence.

  • The Clinical Institute Withdrawal Assessment for Alcohol - revised version (CIWA-Ar) for measuring alcohol withdrawal severity.

  • The Clinical Opiate Withdrawal Scale (COWS) or the Short Opiate Withdrawal Scale (SOWS) for severity of opioid withdrawals.

  • Versions of the 'Grubin tool', a general health screening questionnaire used for prison reception assessments, which are made up of various health elements including for identification of substance use problems.

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 preceding 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

Assessment of risk

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.

Continue reading below

Assessment of social functioning

Issues covered should include:

  • Partners, family and support.

  • Housing.

  • Education.

  • Employment.

  • Domestic violence.

  • Benefits and financial problems.

  • Childcare issues: pregnancy, parenting, child protection.

Assessment of criminal involvement and offending

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.

Assessment of physical and psychological health

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:

Further reading and references

  1. Drug misuse and dependence - UK guidelines on clinical management; GOV.UK, 2017

Article history

The information on this page is written and peer reviewed by qualified clinicians.

symptom checker

Feeling unwell?

Assess your symptoms online for free