Jessica Wong, Matthew Fernando

A 14-year-old boy presents with auditory and visual hallucinations to the emergency department. He sees and hears demons urging him to self-harm. He believes strongly that he is being pursued by demons. He denies suicidal ideation or sense of being possessed. He started to self-harm a year ago. He drinks 20 cans of full-strength beer every weekend and uses marijuana on a daily basis.

Acute-onset psychoses in children and younger adolescents are relatively uncommon and often presents itself in a complex manner. Psychosis is defined as a “disruption in thinking, accompanied by delusions or hallucinations.” Delusions are “false, fixed beliefs that cannot be resolved through logical argument, while hallucinations are false perceptions that have no basis in external stimuli.” [1] 

A key diagnostic element is the onset of psychosis. Acute onset (within a period of less than 2 weeks) may underline a medical disease rather than a psychiatric illness. [2] Anyone who presents with a likely psychiatric diagnosis will need to undergo a medical evaluation to exclude reversible causes of psychosis. [3-5] Let’s look at how to quickly evaluate and manage acute-onset psychosis.

Differential diagnoses of acute onset psychosis in children

Differentials include the following: hypoglycaemia, cerebral hypoxia, drug intoxication, neurological illness and psychiatric diseases. [3-6]

Physical causes:

HypoglycaemiaType 1 or 2 Diabetes Mellitus
Cerebral hypoxiaPulmonary insufficiency
Severe anaemia
Cardiac insufficiency
Drug intoxication and withdrawalAnticholinergic toxicity
Sympathomimetic toxicity
Serotonin syndrome
Benzodiazepine withdrawal
Neurological diseaseCNS mass lesion, infections
Intracranial injury
Postictal psychosis
Autoimmune mediated encephalopathies 

Psychiatric causes:

Psychiatric diseaseDiagnosis by exclusion
Primary psychotic disorders (e.g. schizophrenia, schizoaffective disorder and transient psychotic episodes) 
Mood disorder
Brief psychotic disorder
History of mental illness in family
Emotional trauma

Key points

Hypoglycaemia and cerebral hypoxia are two important diagnoses not to miss!

Drug-induced delusions or psychosis are especially common in the adolescent population

Psychiatric disease is a diagnosis by exclusion – only consider when potentially fatal and reversible causes have been excluded

Taking a History

  • Setting– is the setting suggestive of drug overdose? 
    • For example, abrupt changes in child’s behaviour, adolescent brought from a rock concert
  • History of substance use
    • Common substances related to psychotic symptoms are cannabis, amphetamines, methamphetamines, alcohol, cocaine, GHB and GBL
  • Drug intoxication
    • Often suggested by patient’s current medications e.g. neuroleptic agents
  • Signs of infection
    • Presence of fevers, chills, headache may indicate an infectious cause such as meningitis, encephalitis
  • History of head trauma or any onset of neurological deficits?
    • New onset of neurological deficits suggest stroke, brain abscess/tumour
  • Emotional trauma or family history of psychiatric disease 
    • Points to a potential diagnosis of a psychiatric disease 

Physical Examination

  • Vitals: look for fever (points to infection or drug overdose)
HypoglycaemiaAltered mental status, diaphoresis, tachycardia or hypotension
Cerebral hypoxiaCyanosis, pallor, shock, respiratory distress
Drug intoxicationSerotonin syndrome: agitation, tachycardia, dilated pupils, diaphoresis, diarrhoea

Anticholinergic overdose: fever, dry mucous membranes, decreased or absent bowel sounds, urinary retention 

Sympathomimetic overdose: fever, dilated pupils, present of bowel sounds
Neurological diseaseNeurological examination; any focal or lateralizing examination suggesting brain injury
Psychiatric diseaseTypically has normal vital signs, normal orientation to person, place and time (may not be the case if patients have paranoid beliefs about where they are and about the staff)

Mental status examination e.g. thought disorder, disorientation, delusional beliefs and hallucinations

Hallucinations are usually auditory in nature 


  • Full Blood Count
    • Elevated white cell count may indicate infection
    • Severe anaemia may contribute to cerebral hypoxia 
  • Urea and Electrolytes
    • Identify hypocalcaemia, hypomagnesemia, hypernatremia, hyponatraemia, metabolic acidosis
  • Blood Sugar Level
    • Hypoglycaemia
  • Liver Function Tests 
  • Thyroid Function Tests
  • CT scan
    • In children with head trauma, increased intracranial pressure, focal neurologic deficits [7]
  • Urine drug screen 
  • +/- EEG 
    • In patients with repeated seizures or non-convulsive status epilepticus
  • Other: ECG, LP, Urine pregnancy test 

Key points

In children and adolescents with acute onset psychosis, findings of serious and reversible causes of psychotic presentations such as hypoglycaemia, impaired oxygenation and CNS infections require early recognition and treatment! 

Rapid correction of blood sugar levels is important to prevent seizures and other neurology consequences

Patients with impaired brain oxygenation require immediate treatment to restore oxygenation 

How to approach a paediatric patient with acute onset psychosis?

A child with acute onset psychosis must undergo rapid evaluation that focuses on identifying and treating reversible organic causes. Early evaluation and management of agitation, behaviours that may be risky to oneself (e.g. trying to escape perceived tormentors) or where risk may be directed towards the patient from others can be a critical part of diagnosis and treatment, preventing injury to both the patient and staff. [8,9]

Assessment top tips:


Mental State Assessment

Risk Assessment

Physical Investigations 


  • Listen to the patient
  • Acknowledge and respect patient’s point of view (avoid challenging delusional beliefs, but equally avoid colluding with them)
  • Gather information slowly initially
  • Family involvement

Mental State Assessment

  • Will often not volunteer psychotic symptoms
  • Thought disorder: “trouble with thinking clearly”
  • Hallucinations: “strange experiences recently, hearing voices when no one is there, people talking about you”
  • Delusions: “unusual events recently monitored in any way, strange experiences watching TV, whether they are worried about anyone or anything”
  • It is important to keep in mind that there is no perfect question, but if there’s a sense that something is out of place, then it is important to explore further with the patient

Risk Assessment

  • Ask the patient directly- for example: “do you feel like hurting yourself or someone else?” Sometimes, it is good to relate risk assessment to something else they have mentioned, rather than suddenly asking the question out of context. For instance: “it sounds like it’s been really stressful for you. Sometimes when people are really stressed, they think about hurting themselves – have you ever thought about hurting yourself?”
  • Identify if patient seems guarded or depressed, has hallucinations commanding them to do things (e.g. hurt themselves or others), drug/alcohol abuse or grandiose delusions
  • Also remember to check if there’s any risk to others 

De-escalation techniques

  • Always refer to local protocols and seek senior support when managing acute agitation in children and adolescents, especially if considering using medications
  • First, try doing verbal de-escalation
    • Use clear and calm statements of what will happen in the emergency department 
    • Reassure to the patient about what you are doing and that you are trying to help 
    • Use non-confrontational, but receptive manner with a calm and soothing tone of voice 
    • Reduce environmental stimulation such as loud noise or bright lights
    • Reassure the parent and involve social work and psychiatry when necessary
    • If patient becomes increasingly agitated, have security personnel nearby 
    • If patient cannot be verbally de-escalated, excuse yourself and send for help with the consideration of involving staff trained in physical restraint if there is an immediate risk of harm to the patient or others that cannot otherwise be contained
    • Always have a mechanism that instructs others to call for security when in danger, such as an alarm button 
  • If agitation persists, consider using oral benzodiazepines to reduce agitation
    • Why do we use Benzodiazepines? This is because it is a quick onset drug with a short half-life. Alternatively, we can use antipsychotic agents or promethazine
    • Monitor for and treat side-effects, particularly including respiratory depression with benzodiazepines
  • If oral medications are ineffective or cannot be administered, consider IM treatment (or IV treatment as a last resort)


And that’s how you manage acute onset psychosis in children and adolescents in emergency department in a nutshell!

Always remember to investigate for reversible causes before jumping into the diagnosis by exclusion – psychiatric disease 

Key learning points

  • Psychosis in children and younger adolescents is uncommon
  • Cannabis is a common precipitant to psychosis 
  • An ‘acute’ psychosis requires a medium- to long-term plan for ongoing treatment and monitoring 
  • New onset of psychosis in a child or adolescent must prompt consideration of other medical causes prior to primary psychiatric diagnosis. 
  • Once the patient can be safely evaluated, assess for hypoglycemia, hypoxia, altered mental status, abnormal vital signs and neurologic deficit immediately 

References and further reading

  1. Davids K, Charney D, Coyle J Nemeroff C. Neuropsychopharmacology, Lippincott Williams & Wilkins, Philadelphia 2002.
  2. Panza G, Paletta S. Early-Onset Psychosis with Adolescence Onset. InClinical Cases in Psychiatry: Integrating Translational Neuroscience Approaches 2019 (pp. 1-22). Springer, Cham.
  3. Reimherr JP, McClellan JM. Diagnostic challenges in children and adolescents with psychotic disorders. The Journal of clinical psychiatry. 2004;65:5-11.
  4. Lee HE, Jureidini J. Emerging psychosis in adolescents: a practical guide. Australian family physician. 2013;42(9):624.
  5. Israni AV, Kumar S, Hussain N. Fifteen-minute consultation: an approach to a child presenting to the emergency department with acute psychotic symptoms. Archives of Disease in Childhood-Education and Practice. 2018;103(4):184-8.
  6. Cepeda C. Psychotic symptoms in children and adolescents: assessment, differential diagnosis, and treatment. Routledge; 2006.
  7. Cunqueiro A, Durango A, Fein DM, Ye K, Scheinfeld MH. Diagnostic yield of head CT in pediatric emergency department patients with acute psychosis or hallucinations. Pediatric radiology. 2019;49(2):240-4.
  8. Gerson R, Malas N, Feuer V, Silver GH, Prasad R, Mroczkowski MM, De Pena-Nowak M, Feuer V, Gaveras G, Goepfert E, Gerson R. Best Practices for Evaluation and Treatment of Agitated Children and Adolescents (BETA) in the Emergency Department: Consensus Statement of the American Association for Emergency Psychiatry. Western Journal of Emergency Medicine. 2019;20(2):409.
  9. Aneja J, Singhai K, Paul K. Very early-onset psychosis/schizophrenia: Case studies of spectrum of presentation and management issues. Journal of family medicine and primary care. 2018;7(6):1566.

Written by Dr Jessica Wong, medial intern working in Victoria, Australia

Reviewed by Dr Matthew Fernando, consultant in child and adolescent psychiatry working at the South London and Maudsley NHS Foundation Trust

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