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Psychosis - diagnosis and management

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 one of our health articles more useful.

Important information

Psychosis is a severe mental health problem in which there is extreme impairment of ability to think clearly, respond with appropriate emotion, communicate effectively, understand reality and behave appropriately.

Psychosis occurs in a number of serious mental illnesses and not just schizophrenia - eg, depression, bipolar disorder (manic-depressive illness), puerperal psychosis and sometimes with drug and alcohol misuse. It can also occur in a number of neurological conditions and with drugs not associated with misuse.

Psychosis interferes with the ability to function and can be very debilitating. Disabling symptoms include delusions and hallucinations:

  • A delusion is a false, fixed, strange, or irrational belief that is firmly held. The belief is not normally accepted by other members of the same culture or group. It is important to look at culture, especially with ethnic issues, to decide if strange beliefs are really psychotic. There are delusions of paranoia (plots against them), delusions of grandeur (exaggerated ideas of importance or identity) and somatic delusions (false belief in having a terminal illness).

  • An hallucination is sensory perception (seeing, hearing, feeling, smelling) without an appropriate stimulus, like hearing voices when no one is talking. Not all hallucination suggests psychosis.

See the separate Delusions and Hallucinations article.

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  • The most recent adult psychiatric morbidity survey (2014) found that around 0.5% of people aged 16 years or older in England had received a diagnosis of a psychotic disorder in the preceding year1.

  • An international study found the pooled incidence of all psychotic disorders was 26·6 per 100,000 person-years (95% CI 22·0-31·7)2. Heterogeneity was high (I2 ≥98·5%). Men were at higher risk of all psychotic disorders (incidence rate ratio 1·44 [1·27-1·62]) and non-affective disorders (1·60 [1·44-1·77]) than women, but not affective psychotic disorders (0·87 [0·75-1·00]).

  • UK studies suggest a higher prevalence of psychosis in the black and minority ethnic (BAME) rather than white population3.


Symptoms vary according to the condition but the doctor of first contact will need to address the following general issues:

  • The patient is often brought to the doctor by a third party. This might be because the patient lacks insight but, more likely, because psychosis is a very distressing condition, both for the patient and for those around and a degree of support is required.

  • Occasionally, the first contact may be with family members who have concerns about a member of their family. If the patient cannot be persuaded to come to the surgery, a home visit may be necessary.

  • Where the patient may behave aggressively, consider a joint visit with an experienced community psychiatric nurse and/or the police.

Question the patient directly to discover the symptoms and to ascertain the degree of insight. The accompanying person may be extremely valuable in terms of giving history.

Follow the guidance for psychiatric assessment but history should cover the following ground (the accompanying person may be a very valuable source of information):

  • What is the nature of the hallucination or delusion?

  • What is the time span?

  • Is there a recurring theme?

  • Is there insight into it being unreal?

  • Have there been any recent major life events?

  • Is there a history of substance misuse (alcohol or drugs)?

  • Does the patient's past behaviour suggest psychological vulnerability - eg, irritability, uneasiness, suspiciousness and withdrawn mood?

  • Is there a family history of mental illness?

Whilst taking the history it is possible to make an assessment of the patient's mental state4:

  • Is there loss of touch with reality; are there delusions or a bewildered mood?

  • Is thought or speech disorganised, abstract or vague?

  • Is emotion normal and appropriate? Remember that such experiences will naturally cause extreme anxiety but are there inappropriate emotional outbursts?

  • Is there excitement or confusion?

  • Is there depression or suicidal ideation? Depression can cause psychosis and all forms of mental illness have a risk of suicide, not just depression. There are a number of forms of self-harm assessment.

Physical examination is unlikely to be rewarding in the younger patient but, in the older one, there may be physical signs of alcohol misuse, neurological features and/or other signs of systemic disease. Always look for evidence of poor personal hygiene or self-neglect.

For more information on the presentation of psychosis, see the separate articles listed under 'Differential diagnosis', below.

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Psychosis will usually require urgent referral to mental health services but there are some investigations that can be undertaken in the practice. The management of schizophrenia in primary care is well established but most doctors will want a specialist opinion at the outset.

Differential diagnoses suggest the following tests may be useful:

  • Abnormal LFTs and macrocytosis on FBC are highly suggestive of alcohol misuse5.

  • Serological tests for syphilis6.

  • Screening for AIDS.

  • Urine screen for recreational drugs. Light recreational use of cannabis can produce a positive test for the subsequent fortnight. Heavy and chronic use can produce a positive result for months after the last use7.

  • CT brain scan could exclude a space-occupying lesion or cerebral atrophy if focal signs are present - but not routinely.

Differential diagnosis

The history should help to distinguish between schizophrenia, bipolar disorder and depression; history, however, can be misleading.

Continue reading below


It is very important to recognise and manage a first episode of psychosis correctly, as delay in diagnosis may adversely affect prognosis. If there is an external cause like substance misuse this must be addressed. Remember that psychosis in substance misuse can be part of dual diagnosis7. Family intervention is an evidence-based support programme available in many areas which helps to reduce the relapse rate of psychotic patients in both early and late stages9.

The National Institute for Health and Care Excellence (NICE) emphasises the need to treat all patients who have psychosis with respect throughout the whole care plan, including the experience of compulsory hospitalisation where necessary10.

Aims of treatment11

Important information

Reduce time between appearance of symptoms and initiating therapy (ie duration of untreated psychosis).

Accelerate remission and prevent relapse.

Use both biological and psychological measures.

Maximise the patient's ability to get back to normal life.

Prompt assessment
Admission to a psychiatric unit is often required at the outset. Compulsory admission and possibly enforced treatment under the Mental Health Act may be required. The condition is so distressing that some patients may go voluntarily. The family also tends to prefer the patient to be in a safe environment. See the separate Compulsory Hospitalisation article.

In the initial management of a first episode of psychosis the GP's role will primarily be to make a presumptive diagnosis and arrange secondary care assessment. Occasionally the patient's behaviour will be such that it presents a threat to personal safety or the safety of others. In such circumstances the GP may be required to provide rapid tranquilisation.

First-line treatment in suspected schizophrenia now involves the use of the newer atypical antipsychotics - eg, risperidone or olanzapine is first-line but haloperidol is still used. NICE recommends that GPs should only prescribe such drugs if they are on familiar territory11. Otherwise, close communication with mental health services is required. See also the separate Schizophrenia article.

Mania and hypomania
Drugs used include atypical antipsychotics, benzodiazepines - to aid sleep or reduce agitation - and mood stabilisers such as lithium and carbamazepine (usually under specialist supervision).

Psychosis in depression is usually part of the spectrum of bipolar disorder. See also the separate Bipolar Disorder article.


The outlook in patients with psychosis has improved, due to the policy of early intervention and improvements in drug treatment.

After pharmacological, psychological, and other interventions, many people experience regression or resolution of symptoms, although some negative symptoms may remain4:

  • It is estimated that 80% of people show some response to treatment within the first year.

  • Only 20% of people will have no further psychotic episodes within the following five years.

  • The most common course is initial improvement of symptoms with ongoing recurrent acute psychotic episodes or relapses over many years.

  • It has been reported that around 15% of people experience persistent psychotic symptoms that are unresponsive to treatment two years after the acute episode. These people may require rehabilitation and support including help with activities of daily living.

Factors associated with a poor prognosis include12:

  • Longer duration of untreated psychosis.

  • Early or insidious onset of schizophrenia.

  • Male sex.

  • Negative symptoms.

  • Family history of schizophrenia.

  • Low IQ, low socio-economic status, or social isolation.

  • Significant psychiatric history.

  • Continued substance misuse.

Further reading and references

  1. Adult Psychiatric Morbidity Survey; Survey of Mental Health and Wellbeing, England, 2014, NHS Digital - published 2016 [next survey due 2024]
  2. Jongsma HE, Turner C, Kirkbride JB, et al; International incidence of psychotic disorders, 2002-17: a systematic review and meta-analysis. Lancet Public Health. 2019 May;4(5):e229-e244. doi: 10.1016/S2468-2667(19)30056-8.
  3. Qassem T, Bebbington P, Spiers N, et al; Prevalence of psychosis in black ethnic minorities in Britain: analysis based on three national surveys. Soc Psychiatry Psychiatr Epidemiol. 2015 Jul;50(7):1057-64. doi: 10.1007/s00127-014-0960-7. Epub 2014 Sep 11.
  4. Psychosis and schizophrenia; NICE CKS, September 2021 (UK access only)
  5. Koivisto H, Hietala J, Anttila P, et al; Long-term ethanol consumption and macrocytosis: diagnostic and pathogenic implications. J Lab Clin Med. 2006 Apr;147(4):191-6.
  6. Friedrich F, Geusau A, Greisenegger S, et al; Manifest psychosis in neurosyphilis. Gen Hosp Psychiatry. 2009 Jul-Aug;31(4):379-81. doi: 10.1016/j.genhosppsych.2008.09.010. Epub 2008 Oct 9.
  7. Psychosis with coexisting substance misuse; NICE Clinical Guideline (March 2011)
  8. Sami MB, Shiers D, Latif S, et al; How to approach psychotic symptoms in a non-specialist setting. BMJ. 2017 Nov 8;359:j4752. doi: 10.1136/bmj.j4752.
  9. Onwumere J, Bebbington P, Kuipers E; Family interventions in early psychosis: specificity and effectiveness. Epidemiol Psychiatr Sci. 2011 Jun;20(2):113-9.
  10. Service user experience in adult mental health: improving the experience of care for people using adult NHS mental health services; NICE Clinical Guideline (December 2011)
  11. Psychosis and schizophrenia in adults: treatment and management; NICE Clinical Guideline (Feb 2014 - last updated March 2014)
  12. Sami MB, Shiers D, Latif S, et al; Early psychosis for the non-specialist doctor. BMJ. 2017 Nov 8;357:j4578. doi: 10.1136/bmj.j4578.

Article history

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

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