Psychosis refers to patients suffering a loss of contact with reality. It affects 3 out of 100 people in their lifetime. Psychosis is a constellation of symptoms and signs rather than a diagnosis itself.

Causes of psychosis

  • Schizophrenia
  • Mood disorders:
    • Bipolar affective disorder
    • Severe depression with psychosis
    • Schizoaffective disorder
  • Delusional disorder
  • Post-partum psychosis
  • Unspecified nonorganic psychosis (considered if organic causes excluded and does not fit criteria for other conditions)
  • Medicinal: corticosteroids, Parkinsonian medication, anti-malarials
  • Recreational: psychedelics (LSD, psilocybin), stimulants (cocaine, MDMA), cannabis, alcohol
  • Acute: delirium, encephalitis
  • Degenerative: Parkinson’s, Alzheimer’s
  • Structural: SOL
  • Endocrine: thyrotoxicosis, Addison’s
  • Temporal lobe epilepsy


  • Positive:
    • Hallucinations: auditory, visual, olfactory, tactile
    • Delusions
    • Thought disorder: derailment, poverty, circumstantiality, perseveration, blocking
  • Negative:
    • Social withdrawal
    • Alogia (poverty of speech)
    • Apathy
    • Amotivation
    • Emotional blunting
    • Catatonic behaviour
  • Cognitive


  • Multifactorial and dependent on the cause
  • Primary psychiatric disorders are strongly linked to interactions between genes and environment
  • ‘Positive’ symptoms in psychiatric disorders associated with excess activity of neurotransmitter dopamine at D2-like receptors in the mesolimbic pathway (this forms basis of psychotropic therapy to treat ‘positive’ symptoms
Chronic mental disorder usually developing in early life with 0.5% lifetime risk
Negative symptoms can be indicative of a prodrome
First rank symptoms – last ≥1 month:
– Auditory hallucinations – usually 3rd person in form of running commentary with negative statements
– Thought interference
– Delusions of control
– Delusional perceptions

Questions to consider in a psychosis history

  • Open question: “Has anything odd or unusual been happening recently?”
  • Delusions (ask onset and fixity – how sure they are):
    • Persecutory: “Is anyone out to get you?” “Is anyone plotting against you?”
    • Reference: “Do you feel people are talking about you?”
    • Passivity: “Do you feel you are not in control?”
  • Thought disorder:
    • Form of thought: “Are you able to think clearly?”
    • Thought insertion: “Do you have any thoughts which are not your own?”
    • Thought withdrawal: “Are any thoughts being taken from your mind?”
    • Thought broadcasting; “Can anyone access your thoughts?”
  • Hallucinations:
    • Auditory:
      • “Are you hearing any voices?”
      • “Who are they?”
      • “Can you hear them like you can hear me?”
    • Visual: “Can you see things that others cannot?”
  • Insight: “If I were to say I thought you were unwell, how would you feel?”
What is the difference between hallucinations and pseudohallucinations?
Patients experiencing pseudohallucinations have insight that their experiences are not real and they can stop them.


1. Refer to on-call psychiatric team
2. Full psychiatric assessment (including MSE) and collateral history
3. Rule out organic causes
  • Full physical examination
  • Bloods: FBC, U&Es, LFTs, TFTs, vitamin B12/folate, serology
  • Urine drug screen
  • Imaging: CT/MRI head
  • Lumbar puncture
  • EEG
4. If psychiatric cause:
  • Consider sectioning under Mental Health Act or consider Early Intervention Services if 1st episode (dependent on local services)
  • Bio:
    • 1st line – atypical antipsychotic (PO or IM depot)
    • 2nd – trial another antipsychotic
    • 3rd – clozapine
    • 4th – combination
    • Electroconvulsive therapy (ECT) if catatonic
  • Psycho: psychoeducation, psychotherapy
  • Social: social support, advocacy

Written by Dr Muhammad Zain Haq, Psychiatry Lead (F2)
Reviewed by Dr Patrick Ezeani (Consultant Psychiatrist)

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