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 one of our health articles more useful.
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 https://www.nice.org.uk/covid-19 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.
Dual diagnosis is the term used to describe patients with both severe mental illness (mainly psychotic disorders) and problematic drug and/or alcohol use. Personality disorder may also co-exist with psychiatric illness and/or substance misuse. The term originated from the USA in the 1980s and has been adopted in the UK more recently. The nature of the relationship between the two conditions is well established and may be genetically linked.
- A primary psychiatric illness may precipitate or lead to substance misuse. Patients may feel anxious, lonely, bored, have difficulty sleeping or may want to 'block out' symptoms or medication side-effects.
- Substance misuse may worsen or alter the path of a psychiatric illness.
- Intoxication and/or substance dependence may lead to psychological symptoms.
- Substance misuse and/or withdrawal may lead to psychiatric symptoms or illness. It may act as a trigger in those who are predisposed.
The importance of making the diagnosis
People with dual diagnosis have complex needs relating to health, social, economic and emotional stressors or circumstances which can often be exacerbated by their substance misuse.Efforts to provide support for individuals with a dual diagnosis presents a major challenge.
The principles of dual diagnosis management have not changed since the Department of Health (DH) published its Good Practice Guidance in 2002, viz:
- Engaging the service users in services.
- Retaining them in treatment.
- Using interventions which are evidence-based and target motivation to change.
- Incorporate relapse prevention work as a part of the intervention package.
- Facilitate re-integration into the community.
The scale of the problem
Estimates of prevalence are difficult to come by, not least because various studies have used different diagnostic criteria.
The 2002 Co-morbidity of Substance Misuse and Mental Illness Collaborative study (COSMIC) concluded that:
- 75% of drug service clientele and 85% of alcohol service clientele had mental health problems.
- 44% of mental health service users used drugs or alcohol at hazardous or harmful levels in the previous year.
A 2002 study in Bromley found that dual diagnosis was present in 20% of community mental health clients, 43% of psychiatric inpatients and 56% of people in secure services.
There is a high prevalence of dual diagnosis among prison inmates.
The European Schizophrenia Cohort found that the lifetime rate for people with schizophrenia who were dependent on alcohol or other psychoactive substances was highest in the UK (35%) and considerably lower in Germany (21%) and France (19%).
A study of comorbid substance abuse in psychosis concluded that rates varied depending on service settings, geographical areas and ethnicity. Rates between 20% and 37% were reported in mental health settings, while figures in addiction settings were less clear (6-15%). They were especially high in inpatient and crisis team settings (38-50%) and forensic settings. Rates were highest in inner city areas.
The symptoms of drug or alcohol misuse can be very similar to the symptoms of mental illness, and vice versa, and they frequently co-exist. This can make it difficult to make a confident dual diagnosis. When differentiating between a primary psychotic and a substance-induced disorder, consider:
- Did psychosis precede the onset of substance abuse?
- Does psychosis persist for longer than one month after acute withdrawal or severe intoxication?
- Are the psychotic symptoms consistent with the substance used?
- Is there a history of psychotic symptoms during periods of abstinence?
- Is there a personal or family history of a non-substance-induced psychotic disorder?
Substances which induce psychotic symptoms resulting from substance misuse include:
- Cannabis: intoxication can induce a transient, self-limiting psychotic disorder characterised by hallucinations and agitation.
- Psychostimulants such as amfetamines: when used over prolonged periods these can produce a psychotic picture similar to schizophrenia.
- Hallucinogens: psychosis induced by these is usually transient but can persist with sustained use.
- Alcohol - heavy use: this is associated with morbid jealousy and alcoholic hallucinations. Withdrawal from alcohol may also provoke psychotic symptoms.
A framework for practice around dual diagnosis was produced by the DH in 2002: Dual Diagnosis Good Practice Guide. The Handbook summarised current policy and good practice in the provision of mental health services to people with severe mental health problems and problematic substance misuse.
The Dual Diagnosis Good Practice Handbook has been developed by Turning Point (the UK's leading social care organisation), based on the DH Good Practice Guide. Its purpose is to help practitioners to plan, organise and deliver services for people with dual diagnosis. It contains case studies from services working with people with a dual diagnosis in a range of settings and localities, offering practical help for those wanting to establish dual diagnosis services.
In 2002, the Royal College of Psychiatrists' Research Unit was also commissioned by the DH to produce an information manual for practitioners working in the field of dual diagnosis.
The DH also issued guidance in 2006 on the assessment and management of patients in mental health inpatient and day hospital settings who have mental ill-health and substance use problems. It covers information on service planning and needs assessment, clinical management (assessment, care and treatment, discharge and follow-up), as well as organisation and management of services.
In 2009, the DH and the Ministry of Justice issued guidance on the management of dual diagnosis in prisons.
The National Institute for Health and Care Excellence (NICE) is working on dual diagnosis guidelines with an anticipated publication date of September 2016.
- Screen all patients with psychosis for substance misuse.
- Determine the severity of use and associated risk-taking behaviours.
- Exclude organic illness or physical complications of substance misuse (including any possible medication and substance interactions).
- Seek collateral history from family or close supports wherever possible.
- Consider carer needs.
- Determine the individual's expectation of treatment and the degree of motivation for change.
- Do a risk assessment to include risk of self-harm, self-neglect, risk of violence to others and risks from others, including exploitation.
The reorganisation of the NHS and the institution of clinical commissioning groups have led to a refocusing of care. A Care Services Improvement Partnership survey in 2008 found that 4 out of 10 Local Implementation Teams did not have dual diagnosis strategies. Increasing numbers of NHS Trusts have now developed them. Primary care working alongside other disciplines has a role to play in ensuring that those with mental health problems are able to access appropriate services. Physical health needs should also be considered fully. This will form part of the new Proactive Care Programme that has been introduced as a new enhanced GP service.
There has been a tendency in the past to find appropriate referral difficult, as those with dual diagnosis may 'fall between the two stools' of psychiatric services and drug and alcohol agencies; however, the need for better co-ordination and clearer care pathways is strongly advocated. The DH 2002 guidance stated that treatment for dual diagnosis should be delivered within mental health services, known as 'mainstreaming'. The suggestions the guidance makes include the following key points:
- Local services must be developed according to need with care pathways and clinical governance guidelines drawn up.
- Specialist dual diagnosis workers should provide support to mainstream mental health services where they exist.
- There should be adequate staff training around dual diagnosis.
- A Care Programme Approach (CPA), including the concept of a keyworker and full risk assessment, should be used in clients with dual diagnosis.
In some areas, specialist teams already exist to tackle the specific needs of those with dual diagnosis. They usually adopt an outreach working model as well as supporting mainstream mental health services. In other areas where this is not the case, the aim should be to mainstream the care of those with dual diagnosis. Often those doing crisis resolution, early intervention and assertive outreach work have the most contact with the dually diagnosed and should receive specific training. The approach should be non-judgmental and service users, carers and families should be involved in treatment where possible. Services should also be culturally appropriate.
Despite these avowed intentions, problems still exist. Poor communication, poor information sharing, inflexible appointment times and overly stringent service entry criteria all present obstacles to dual diagnosis service users. It is hoped that the current governmental strategy, ‘No health without mental health’, and the commissioning restructuring of the health service will help to remove these obstructions.[4, 19]
Stages in treatment
- Persuasion (working towards change).
- Active treatment.
- Relapse prevention including identification of triggers for relapse, and development of alternative coping strategies.
- Harm reduction: supervised consumption, needle exchanges, looking at wider health needs (eg, hepatitis and HIV exposure).
- Stabilising consumption: establishing treatment programmes (detoxification, substitute prescribing, counselling and psychological treatments).
- Education: improving awareness of risk-taking behaviour, explaining how to find support.
- Addressing social care needs including possible triggers for substance misuse.
- Treatment of mental health problems: drug treatment, psychosocial therapy, complementary therapies.
- Worsening psychiatric symptoms.
- More frequent rehospitalisation.
- Poor physical health.
- Poor medicine adherence.
- Homelessness and poverty.
- Increased risk of HIV infection.
- Poor social outcome (including impact on family, education, carers and employment).
- A personal history of sexual abuse.
- Financial pressures.
- Increased risk of violence and contact with the criminal justice system.
- Increased risk of suicide.
- Isolation and social withdrawal.
An All-Party Parliamentary Group has been established to investigate why barriers to equal access, integrated care and high-quality support exist.The inquiry is ongoing, with a proposed timeframe of 18 months,and will combine the use of surveys, evidence sessions, group discussions and ongoing dialogues with stakeholders. It is hoped that areas of good practice can be rolled out to enable more consistent access to services for people with dual diagnosis and other complex needs.
Further reading and references
Hackman DT, Greene MS, Fernandes TJ, et al; Prescription drug monitoring program inquiry in psychiatric assessment: detection of high rates of opioid prescribing to a dual diagnosis population. J Clin Psychiatry. 2014 Jul75(7):750-6. doi: 10.4088/JCP.14m09020.
Pettersen H, Ruud T, Ravndal E, et al; Walking the fine line: self-reported reasons for substance use in persons with severe mental illness. Int J Qual Stud Health Well-being. 2013 Dec 208:21968. doi: 10.3402/qhw.v8i0.21968.
Di Lorenzo R, Galliani A, Guicciardi A, et al; A retrospective analysis focusing on a group of patients with dual diagnosis treated by both mental health and substance use services. Neuropsychiatr Dis Treat. 2014 Aug 1110:1479-88. doi: 10.2147/NDT.S65896. eCollection 2014.
Crome I et al; The relationship between dual diagnosis: substance misuse and dealing with mental health issues, Social Care Institute of Excellence, 2009.
Graham J; Better provision for people with dual needs Homeless Link, 2013
Dual Diagnosis - Good Practice Guidance, (Mental Health Policy Implementation Guide); Dept of Health, 2002
Carra G, Johnson S, Bebbington P, et al; The lifetime and past-year prevalence of dual diagnosis in people with schizophrenia across Europe: findings from the European Schizophrenia Cohort (EuroSC). Eur Arch Psychiatry Clin Neurosci. 2012 Oct262(7):607-16. doi: 10.1007/s00406-012-0305-z. Epub 2012 Mar 17.
Carra G, Johnson S; Variations in rates of comorbid substance use in psychosis between mental health Soc Psychiatry Psychiatr Epidemiol. 2009 Jun44(6):429-47. Epub 2008 Nov 13.
Lubman DI, Sundram S; Substance misuse in patients with schizophrenia: a primary care guide. Med J Aust. 2003 May 5178 Suppl:S71-5.
Co-existing Problems of Mental Disorder and Substance Misuse (dual diagnosis) - An Information Manual 2002; Royal College of Psychiatrists
Dual diagnosis in mental health inpatient and day hospital settings; Dept of Health, October 2006
Bahorik AL, Newhill CE, Queen CC, et al; Under-reporting of drug use among individuals with schizophrenia: prevalence and predictors. Psychol Med. 2014 Jan44(1):61-9. doi: 10.1017/S0033291713000548. Epub 2013 Apr 3.
Dual diagnosis toolkit; Rethink/Turning Point
Dual Diagnosis Local Strategies; National Consortium of Consultant Nurses in Dual Diagnosis & Substance Use - Progress, 2014
Transforming Primary Care; Dept of Health, 2014
No health without mental health; HM Government, 2011
Chakraborty R, Chatterjee A, Chaudhury S; Impact of substance use disorder on presentation and short-term course of schizophrenia. Psychiatry J. 20142014:280243. doi: 10.1155/2014/280243. Epub 2014 Apr 2.
Soyka M; Substance misuse, psychiatric disorder and violent and disturbed behaviour. Br J Psychiatry. 2000 Apr176:345-50.