Acute Behavioural Disturbance (ABD)

Acute Behavioural Disturbance (ABD)

Acute behavioural disturbance (ABD) is a clinical presentation rather than a diagnosis and may arise from a wide range of medical, substance-related, neurological, or psychiatric causes. It is essential that clinicians avoid making assumptions about the underlying cause based solely on a patient's behaviour, appearance, or past medical history, as this can lead to diagnostic error, delayed treatment, and poorer patient outcomes.

A thorough and systematic assessment is crucial to identifying the underlying cause of the behavioural disturbance. Recognising whether the presentation is driven by an acute medical condition (such as hypoxia, hypoglycaemia, sepsis, delirium, or traumatic brain injury), substance intoxication or withdrawal, or a primary mental health disorder allows clinicians to deliver appropriate, timely, and targeted treatment. Early identification of the underlying cause not only improves patient safety and clinical outcomes but can also reduce the risk of escalation, minimise the need for restrictive interventions, and enhance the patient's overall experience within the emergency department. Maintaining a compassionate, non-judgemental, and trauma-informed approach throughout assessment and management helps preserve patient dignity while fostering trust and engagement with care.

Non Medical

  • Relationship conflict
  • Anniversaries of past traumatic events
  • Interactions with police or security staff
  • Family violence
  • Poor prehospital care experience
  • Distress experience by people with intellectual disability or autism
  • Prolonged waiting times
  • Distress from suicidal thoughts
  • Bereavement

General Medical

  • Head trauma
  • Encephalitis, meningitis, or other infection
  • Encephalopathy, particularly from liver or renal failure
  • toxins, including prescription medication
  • Pain, especially in people with intellectual disability or autism
  • Metabolic derangements e.g hyponatraemia
  • Hypoxia
  • Thyroid disease
  • Seizures or post ictal

Intoxication or Withdrawal

  • Alcohol
  • Nicotine
  • CNS stimulants e.g. cocaine, amphetamine-type substances
  • CNE depressants e.g. GHB, benzodiazepines, opioids
  • Novel psychoactive substances e.g. synthetic cannabinoids
  • Hallucinogens and dissociative e.g. LSD, magic mushrooms

Psychiatric

  • Psychotic disorders
  • Mania
  • Agitated depression
  • Anxiety disorders
  • Personality disorders 
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