• 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.

Epidemiology

• About 3% of the population will experience psychosis at some time in their lives, the age of onset is usually between 15 and 30.
• Women tend to present at a slightly older age than men and they are more susceptible at certain times, such as when pre-menstrual, the puerperium and the menopause.

Presentation

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. ²
• 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 abuse (alcohol or drugs)?³
• Does the patient's past behaviour suggest psychological vulnerability, e.g. irritability, uneasiness, suspiciousness and withdrawn mood?²
• Is there a family history of mental illness?

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

• Is there loss of touch with reality, delusions or 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? ³ 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 abuse, 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 our dedicated articles on Schizophrenia and Mania and Hypomania.

Investigations

Psychosis will usually require 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.

• Abnormal LFTs and macrocytosis on FBC are highly suggestive of alcohol abuse.
• Serological tests for syphilis should not be forgotten. Screening for AIDS should be preceded by counselling.
• Urine screen for drugs of abuse. Light recreational use of cannabis can produce a positive test for the next fortnight. Heavy and chronic use can produce a positive results for months after the last use.
• Brain scan may show a space occupying lesion or cerebral atrophy.

Differential diagnosis

The history should help distinguish between schizophrenia, bipolar disorder and depression but history can be misleading.
See the articles on Schizophrenia, Mania and Bipolar and Manic Depression for further details.

Management

It is very important to recognise and manage a first episode of psychosis correctly as delay in diagnosis may adversely affect ultimate prognosis.⁴ If there is an external cause like substance abuse this must be addressed. Remember that psychosis in substance abuse can be part of dual diagnosis.

Prognosis

The outlook in patients with psychosis is not as bleak as it once was due to the policy of early intervention and improvements in drug treatment. However, It must not be forgotten that psychosis can lead to disastrous consequences. Suicide can occur in any form of mental illness. A study of young people in Sweden, followed up for 10 years showed that 2.5% had killed themselves and 25% had attempted suicide.⁵

One study found that factors which determined 5 year prognosis after a first episode of psychosis included Global Assessment of Functioning (GAF) score during the year before first admission, education level, actual GAF score at first admission, gender, and social network.⁶ Another found that 20% of patients were in symptomatic and functional remission within 2 years.⁷

Psychosis appears to deteriorate rapidly in the early stages before reaching a level of stability. Any effective early intervention is therefore likely to improve the long-term prognosis.⁸