Assessing a first episode of psychosis in adults and young people

When assessing an adult or young person with psychotic symptoms for the first time, consider:
  • a psychotic disorder is usually diagnosed when signs and symptoms of psychosis (including at least one positive sign or symptom) persist for at least 1 week and cause distress and functional impairment, and other causes have been excluded
  • transient positive signs and symptoms are not uncommon—up to 10% of people experience a symptom at some stage in their lives and mostly do not develop a psychotic disorder (see Possible diagnoses in a patient experiencing positive psychotic signs or symptoms for other common causes)
  • it may not be possible to distinguish the diagnosis initially—it may be clarified by the longitudinal course of the disorder. For example, a brief psychotic episode or schizophreniform disorder cannot be diagnosed until symptoms resolve, and is frequently reclassified as schizophrenia if symptoms persist or recur
  • it can be difficult to elicit symptoms of psychosis from a patient because the patient may not disclose their symptoms or may lack insight into their pathological nature. Furthermore, as a result of psychosis, a patient can develop cognitive impairment (often before the onset of psychosis)
  • assessment is best undertaken by a specialist—refer people with psychotic symptoms to a psychiatrist or mental health service. Young people should ideally be referred to a youth mental health service such as Headspace, if available. The urgency of review depends on the acuity of the patient’s presentation.

Before comprehensively assessing a person with psychotic symptoms, determine if they pose a threat to themselves or others. If there is a risk of harm, see Approach to managing acute behavioural disturbance.

Table 1. Signs and symptoms of psychotic disorders

[NB1]

Positive signs and symptoms

hallucinations (eg hearing voices)

delusions (eg persecutory, bizarre, grandiose)

impaired insight

disorganised thinking and speech

Negative signs and symptoms

lack of motivation

poor self-care

blunted affect

reduced speech

social withdrawal

Cognitive signs and symptoms

impaired planning

reduced mental flexibility

impaired memory and concentration

impaired social cognition [NB2]

Excitement

disorganised behaviour

aggression

hostility

catatonia

Note:

NB1: At least one positive sign or symptom must be present to diagnose a psychotic episode.

NB2: Social cognition includes emotion recognition, theory of mind and understanding social rules.

Figure 1. Possible diagnoses in a patient experiencing positive psychotic signs or symptoms
Positive psychotic signs and symptoms are a feature of many conditions that should be considered as possible diagnoses:
Note:

NB1: The duration of signs and symptoms required for these diagnoses is arbitrary.

NB2: The stability of this diagnosis is poor—patients often relapse and are subsequently diagnosed with another disorder (eg schizophrenia).

NB3: If signs or symptoms persist for longer than expected, see Substance-induced psychotic disorder.

If it is safe to do so, observe patients with psychotic signs or symptoms for 24 to 48 hours before starting antipsychotic therapy. During this time:

When acute signs and symptoms have settled, undertake neurocognitive testing, if available, to identify cognitive deficits, because cognitive symptoms require targeted treatment.

Figure 2. Assessments to help identify cause(s) of psychotic signs and symptoms.

[NB1]

Assessments to help identify cause(s) of psychotic signs and symptoms include:

  • a comprehensive history, including:
    • details of the presenting symptoms
    • a developmental history, including details about relationships, employment, function and early life stress or trauma
    • family history, including mental and physical health
    • medical and psychiatric history, including treatment history
    • substance use, including alcohol, tobacco and other drugs
  • mental state examination
  • physical examination and neurological assessment; check blood pressure, heart rate, temperature and respiratory rate
  • investigations, including
    • full blood count
    • blood electrolytes (including calcium), creatinine and urea concentrations
    • liver biochemistry
    • blood glucose concentration
    • thyroid function tests
    • urine toxicology
    • inflammatory markers (eg erythrocyte sedimentation rate [ESR], C-reactive protein [CRP])
  • oxygen saturation (with or without blood gas measurement)
  • electrocardiogram (ECG)
  • brain imaging (eg computerised tomography [CT], magnetic resonance imaging [MRI]).

Additional assessments for people at risk of conditions associated with psychotic signs and symptoms, include:

  • hepatitis C serology for people at risk of hepatitis C
  • human immunodeficiency virus (HIV) antibody/antigen testing and syphilis serology for people at risk of a sexually transmitted infection
  • pain assessment in people at risk of delirium
  • electroencephalogram (EEG) when indicated (eg a history of head trauma, seizures)
  • antinuclear antibodies (ANA), N-methyl-D-aspartate (NMDA) receptor antibodies, and anti–glutamic acid decarboxylase (anti-GAD) antibodies for people at risk of autoimmune psychosis (eg NMDA receptor encephalitis); seek expert advice for further assessment.
Note: NB1: Some of the assessments used to identify cause(s) of psychosis are also baseline parameters potentially affected by antipsychotic therapy and are listed in Baseline parameters potentially affected by antipsychotic therapy; these do not need to be performed twice.
Figure 3. Baseline parameters potentially affected by antipsychotic therapy.

[NB1]

Note:

BMI = body mass index

NB1: Some of the baseline parameters potentially affected by antipsychotic therapy are also assessed to identify cause(s) of psychosis and are listed in Assessments to help identify cause(s) of psychotic signs and symptoms; these do not need to be performed twice.

NB2: Also consider screening for sexual difficulties and, in females of childbearing potential, taking a menstrual history.