NICE recommends that all individuals with psychosis or suspected psychosis and possible substance misuse are referred to secondary care, says Professor Peter Tyrer
  • Psychosis and substance misuse commonly occur together
  • Healthcare professionals in all settings should enquire about substance misuse in people with psychosis or suspected psychosis. Ask about:
    • substance(s) used
    • quantity, frequency, and pattern of use
    • duration of current level of use
    • route of administration
  • People with psychosis or suspected psychosis and possible co-morbid substance misuse should be referred
  • Continuity of care should be preserved as much as possible
  • Testing for substance use should only be performed if agreed with the patient
  • Treatment plans should take into account relative severity of psychosis and substance misuse, context of treatment, and the person's readiness to change
  • Management should follow NICE recommendations from appropriate guidelines (e.g. NICE Clinical Guideline 38 on Bipolar disorder: the management of bipolar disorder in adults, children and adolescents, in primary and secondary care).

Healthcare professionals are inundated with guidelines on the management of individual disorders in medicine so it is fair to ask about the need for NICE guidance that combines two conditions: psychosis and coexisting substance misuse.1,2 The rationale for linking substance misuse and psychosis is that this particular combination is of major importance in the health service. The psychoses concerned include schizophrenia (a plural term that includes schizoaffective disorder, delusional disorders, and related conditions), bipolar disorder, and other affective psychosis. In the NICE guideline, ‘substance misuse’ is a broad term covering the harmful use of any psychotropic substance, including alcohol and either illegal or illicit drugs. The word ‘misuse’ applies where there is evidence of dependence, including both drug-seeking behaviour and in some cases, withdrawal symptoms after stopping the drug; misuse can be harmful even if there is no dependence.1,2

The combination of psychosis and substance misuse is surprisingly common; approximately 40% of all people with psychosis, misuse substances at some point in their lifetime—this is double the rate observed in the general population.1,2 The main differences between psychosis and substance misuse, and a combination of these two conditions, are illustrated in Table 1.

Table 1: The main differences between psychosis and substance misuse and a combination of these two disorders3–5
Psychosis with substance misuse
Psychosis alone
Substance misuse alone
Prevalence (%)
Response to treatment
(in motivated individuals)
(in motivated individuals)
Relapse rate
Hospital admission
Very high
Cost of care
Very high

Consequence of psychosis and substance misuse

There are three reasons why psychosis and substance misuse create so many problems in the health service:

  • High prevalence of this disorder—there are no convincing explanations as to why these two conditions should be such a common co-occurrence. There are many suggestions, including the possibility that drug misuse brings on the diagnosis of schizophrenia or other psychoses in individuals who would never otherwise develop the condition; the prevalence of psychosis, however, is not increasing,6 despite evidence showing that psychosis is manifest at an earlier age in those who abuse drugs7
  • Substance misuse interferes with the diagnostic picture and makes treatment of psychosis more difficult. There is now abundant evidence that substance misuse is linked with psychiatric disorders, and psychosis in particular is associated with significantly poorer outcomes when linked with substance misuse than if it were present alone (see Table 1).1,5 It is also clear that in the longer term, patients with psychosis and co-morbid misuse have many more relapses, are less adherent to prescribed psychotropic medication, have higher rates of homelessness, increased risk of infection with human immunodeficiency virus, and greater drop out from services1,2
  • Cost of care for patients with psychosis and substance misuse are very much greater than those with psychosis alone.8 Although much of the extra costs are incurred in institutional care, there is also greater use of primary care services by patients with a combination of psychosis and substance misuse.

Detection and management

It is not particularly easy to identify psychosis and co-morbid substance misuse, especially in young people because there is stigma and discrimination associated with both of these conditions, and people feel that disclosure of these problems may be associated with compulsory treatment or imprisonment or, for example, having their children taken into care. It is better to identify a pattern of problems early, and GPs may therefore be in a good position to detect psychosis and co-morbid substance misuse at the most opportune time. In particular, individuals who present with psychotic disorder—even though it may appear to be the only condition presenting problems—should be asked about substance use; and when such patients are admitted to hospital, they should be placed in a therapeutic environment that is free from drugs and alcohol.1,2

Asking people about their drug use can be linked with drug and alcohol testing, but this should be done voluntarily whenever possible. It also helps greatly if continuity of care is preserved as much as possible when managing psychosis and substance misuse,1,2 not least because there tend to be many transfers of care in the pathways for this group of patients. As confidentiality and privacy are valued as important by people with these co-morbid disorders, it helps greatly to limit the number of professionals normally involved with their care. Although commissioned by the NHS, many services for drug misuse are now in the voluntary sector, and it is particularly important to collaborate with workers in this setting and to include them in the care programme policies for this patient group.

Key messages

Most of the important elements of the NICE guideline are related to enhancing awareness of psychosis and substance misuse (see Table 2). This includes:

  • asking about substance misuse at all routine assessments of people with suspected psychosis
  • involving patients and voluntary services more actively in discussions about diagnosis and management
  • encouraging testing for drugs in cases of suspected consumption but not without permission
  • applying a low threshold for referral to secondary care services.

If substance use has been identified, it is important for healthcare professionals in all settings (primary care may face difficulties because of time constraints) to ask the person about:1,2

  • the substance(s) being used
  • quantity, frequency, and pattern of use
  • duration of current use
  • route of administration.
Table 2: Key recommendations from the NICE guideline on the assessment and management of psychosis with coexisting substance misuse1,2
NICE guideline recommendation
What usually happens now
How the guideline should improve care

Adults and young people with known or suspected psychosis should be asked routinely about their use of alcohol and/or prescribed and non-prescribed (including illicit) drugs by healthcare professionals from all settings, including primary care

These additional questions are often forgotten in busy clinical practice because the manifestations of psychosis are so florid

Earlier identification should help to guide treatment and prevent more major pathology

If a person has used substances, they should be asked about the following:

  • Particular substance(s) used
  • Quantity, frequency, and pattern of use
  • Duration of current level of use
  • Route of administration

Although there is increasing awareness of drug and alcohol use it is often underestimated (less often overestimated) because assumptions are made about consumption that may be very wrong. This is particularly relevant when prescribing drugs for other conditions, including psychosis, which may interact with illicit drugs

Awareness of this problem should help in better prescribing

All adults and young people with psychosis or suspected psychosis, including those who have possible coexisting substance misuse, should be referred to either secondary care mental health services or child and adolescent mental health services for assessment and further management

The GP may feel everything can be managed in primary care because of the difficulties sometimes experienced in directing patients to the correct referral pathway and the wishes of parents and carers to minimise the significance of co-morbid diagnosis

Appropriate expertise can be available much earlier in the care pathway

All inpatient mental health services should ensure that they have policies and procedures for promoting a therapeutic drug- and alcohol-free environment, which has been developed together with service users and their families, carers, or significant others

Unfortunately, many institutional settings, including wards in NHS psychiatric units, have become places where drugs and alcohol are misused openly

Tougher monitoring should prevent this abuse

Service users should be provided with full information appropriate to their needs about the management of psychosis and co-morbid substance misuse to ensure informed consent. This should happen prior to undertaking any investigations for substance misuse and before each treatment decision is made.

There is sometimes an urge to test or plan treatment in people with psychosis and substance misuse without prior discussion, but this is unethical

This should lead to better collaborative care in which patients and their carers are more involved with planned treatment

Healthcare professionals in primary care and secondary care mental health services, and specialist substance misuse services, should work collaboratively with voluntary sector organisations that provide services for adults and young people with psychosis and coexisting substance misuse to develop agreed protocols for routine and crisis care

The links between statutory and voluntary service sectors are often poor and there is insufficient awareness of the other's role

Better links should improve continuity of care, which is often lacking in current services, but highly important in terms of therapeutic outcome

Biological or physical tests for substance use (e.g. blood and urine tests or hair analysis) may be useful in the assessment, treatment, and management of substance misuse in adults and young people with psychosis. However, this should be agreed with the person first as part of their care plan.

There is sometimes a gullible acceptance of verbal reports of drug misuse, which can be greatly contradicted by evidence from biological tests

Proper awareness of drug and alcohol use should aid advice and treatment

Recommendations relevant to primary care

All adults and young people who present with psychosis and co-morbid substance misuse, or who are suspected of having this combination of disorders, should be referred to secondary mental healthcare services or child and adolescent mental health services for assessment and further management. For most adults with psychosis and coexisting substance misuse, treatment should be provided by the same clinical teams, usually secondary mental healthcare services such as community based mental health teams. In many cases, it may be valuable to initiate joint-working arrangements with specialist substance misuse services in these teams.

If substance misuse is recognised by primary care, even if it is at a low level, it should be communicated to other relevant professionals in secondary care services, as a dose that would not normally be considered to be a problem in people without psychosis may become so in those who have a psychotic disorder.

Testing for substance misuse (including blood and urine tests and hair analysis) may be useful in assessment and treatment, but this should be agreed with the person first as part of their care plan. The use of biological and physical tests in routine screening is not recommended.1,2


In developing any treatment plan for psychosis and co-morbid substance misuse, some account has to be made for the relative severity of the psychosis and substance misuse, the context of treatment, and the person’s readiness for change; it is usually the case that poorer outcomes are more likely if a person’s motivation is low (see Table 1, p.10). The NICE guideline was unable to identify any specific treatment that would be of special value in this co-morbid group but further research on psychosocial, environmental, and pharmacological interventions was recommended by the Guideline Development Group.1,2

Practitioners should follow NICE guidance on the appropriate psychotic disorder (e.g. Clinical Guideline [CG] 38 on bipolar disorder;9 CG82 on schizophrenia10) and equivalent guidance for substance misuse (e.g. CG100 on alcohol-use disorders;11 CG51 on psychosocial interventions for drug misuse12).

Contingency management is a psychosocial intervention that shows particular promise.1 It rewards people for complying with treatment and, as adherence is so poor in this patient group, this approach may be of value and has been supported by the results of small trials.13 However, there are important ethical considerations about payment, the most common form of reward, and the implications of this need to be explored before this approach is used. Integrated motivational interviewing and cognitive therapy may also be of value, but do not have clear evidence of efficacy; a recent large Medical Research Council trial was essentially negative in its findings and only found slight evidence for better outcomes in people with psychosis and drug dependence.14

There is some evidence that the environments of individuals with psychosis and substance misuse may be responsible, to some extent, for continued impairment and relapse. The evidence suggests that, ‘ ... when the primary focus of management involves improving the environment, both conditions may improve’.1

In the absence of specific evidence, US researchers have suggested that integrating services for psychosis alone and psychosis with substance misuse results in better outcomes,15 but the NICE Guideline Development Group was unable to confirm this on the evidence available, and it seems unlikely that this will be introduced into the UK.


Psychosis and substance misuse is an important pathological combination that needs to be recognised early in care as it leads to complications in the treatment and outcome of both conditions. Smoother pathways to secondary care are likely to improve both identification and outcomes of psychosis and substance misuse. As much as possible, all interventions and tests should be carried out collaboratively to improve adherence to the treatment programmes for each condition. There is little evidence that any one treatment is indicated specifically for psychosis and substance misuse, but pharmacological, environmental, and psychosocial interventions, particularly contingency management, are of value.

Implementation tools

NICE has developed the following tools to support implementation of Clinical Guideline 120 on Psychosis with coexisting substance misuse: assessment and management in adults and young people. The tools are now available to download from the NICE website:

Baseline assessment tool

The baseline assessment tool is an Excel spreadsheet that can be used by organisations to identify if they are in line with practice recommended in NICE guidance and to help them plan activity to enable them to meet the recommendations.

Clinical audit tool

Audit tools aim to assist organisations with the audit process, thereby helping to ensure that practice is in line with the NICE recommendations. They consist of audit criteria and data collection tool(s) and can be edited or adapted for local use.

Clinical case scenarios

The clinical case scenarios illustrate how the recommendations from the NICE guideline on psychosis with coexisting substance misuse can be applied to the care of patients in primary, secondary, and third-sector services.

Costing statement

The costing statement estimates the financial impact to the NHS of implementing this clinical guideline. This statement focuses on the financial impact of the recommendations that require most change in resources to implement in England.


A member of the Guideline Development Group discusses implementation of the guidance for GPs within primary care.

Slide set

The slides provide a framework for discussing the NICE guideline with a variety of audiences and can assist in local dissemination. This information does not supersede or replace the guidance itself.

  • Commissioners should be aware of the poor prognosis and high hospital utilisation rates in people with co-morbid psychosis and substance misuse
  • As psychiatric services fall outside the national PbR tariff, prices for interventions or pathways will need to be negotiated locally
  • Although psychiatric services are not included in the PbR mandatory tariff, hospital costs in this patient group often do fall within the PbR framework (medical admissions and accident and emergency)
  • Commissioners should ensure that there is a clear local pathway for the identification of this group of patients and rapid referral to specialist services
  • Contracts with specialist psychiatric providers should define clear pathways for patients on hospital discharge and ongoing community care.

PbR=Payment by Results

  1. National Collaborating Centre for Mental Health. Psychosis with coexisting substance misuse: assessment and management in adults and young people. Clinical Guideline 120. London: NICE, 2011. Available at:
  2. National Institute for Health and Care Excellence. Psychosis with coexisting substance misuse: assessment and management in adults and young people. Clinical Guideline 120. London: NICE, 2011. Available at:
  3. Kendler K, Gallagher T, Abelson J, Kessler R. Lifetime prevalence, demographic risk factors, and diagnostic validity of nonaffective psychosis as assessed in a US community sample. The National Comorbidity Survey. Arch Gen Psychiatry 1996; 53 (11): 1022–1031.
  4. Farrell M, Howes S, Taylor C et al. Substance misuse and psychiatric comorbidity: an overview of the OPCS National Psychiatric Morbidity Survey. Addict Behav 1998; 23 (6): 909–918.
  5. Menezes P, Johnson S, Thornicroft G et al. Drug and alcohol problems among individuals with severe mental illness in south London. Br J Psychiatry 1996; 168 (5): 612–619.
  6. Kirkbride J, Croudace T, Brewin J et al. Is the incidence of psychotic disorder in decline? Epidemiological evidence from two decades of research. Int J Epidemiol 2009; 38 (5): 1255–1264.
  7. Barnes T, Mutsatsa S, Hutton S et al. Comorbid substance use and age at onset of schizophrenia. Br J Psychiatry 2006; 188: 237–242.
  8. McCrone P, Menezes P, Johnson S et al. Service use and costs of people with dual diagnosis in South London. Acta Psychiatr Scand 2000; 101 (6): 464–472.
  9. National Institute for Health and Care Excellence. Bipolar disorder: the management of bipolar disorder in adults, children and adolescents, in primary and secondary care. Clinical Guideline 38. London: NICE, 2006. Available at:
  10. National Institute for Health and Care Excellence. Schizophrenia: core interventions in the treatment and management of schizophrenia in adults in primary and secondary care. London: NICE, 2009. Available at: nhs_accreditation
  11. National Institute for Health and Care Excellence. Alcohol use disorders: diagnosis and clinical management of alcohol-related physical complications. Clinical Guideline 100. London: NICE, 2010. Available at: nhs_accreditation
  12. National Institute for Health and Care Excellence. Drug misuse: psychosocial interventions. Clinical Guideline 51. London: NICE, 2007. Available at: nhs_accreditation
  13. Cleary M, Hunt G, Matheson S, Walter G. Psychosocial treatments for people with co-occurring severe mental illness and substance misuse: systematic review. J Adv Nurs 2009; 65 (2): 238–258.
  14. Barrowclough C, Haddock G, Wykes T et al. Integrated motivational interviewing and cognitive behavioural therapy for people with psychosis and comorbid substance misuse: randomised controlled trial. BMJ 2010; 341: c6325.
  15. Drake R, Essock S, Shaner A et al. Implementing dual diagnosis services for clients with severe mental illness. Psychiatr Serv 2001; 52 (4): 469–476. G