Major depression esp. post ECT
Alcohol excess incl. Korsakoff syndrome
Iatrogenic e.g. ECT, cardiac bypass surgery
Serious disorders not to be missed
B1 deficiency incl. alcohol abuse
Dissociative fugue states
Drugs: various e.g. Cannabis, amphetamines (see list)
Thyroid/other endocrine: hypercalcaemia/hypothyroid?
Is the patient trying to tell me something?
Conversion reaction (hysterical fugue)
A careful history is required recording the nature of memory loss incl. onset, duration, fluctuation and associations. Interview family members and check for possible bizarre behaviour. The key history should incl. past medical history including diabetes, hypertension, cerebrovascular disease; drug history esp. alcohol, smoking or illicit drugs (cannabis, amphetamines, opioids, solvent sniffing), lithium, barbiturates, benzodiazepines, anticonvulsants, digoxin, OTC drugs, etc.; and psychiatric history, incl. severe anxiety, stress, depression, fugue features, dissociation or personality disorder.
General features: appearance of patient incl. central cyanosis, hydration status, vital signs
Psychiatric assessment and mental state examination
Consider memory loss as a presenting feature of severe stress, anxiety or depression (which can present as pseudo dementia in the elderly).