Capgras delusion

• Capgras delusion refers to a delusion that either oneself or another person has been replaced by an exact clone
• It may be part of a psychotic illness or as a result of trauma to the brain

Ekbom's syndrome

• Ekbom's syndrome is a delusional belief where a patient feels that they are infested with parasites
• They often complain of feeling ‘crawling’ in the skin
• It can appear as part of a psychotic illness or a secondary organic disease such as B12 deficiency, hypothyroidism and neurological disorders

Cotard delusion

• Cotard delusion refers to the belief that a patient is dead, non-existent or 'rotting'
• Again, it may occur in psychosis but can appear as a result of parietal lobe lesions

Othello syndrome

• Othello syndrome is a strong delusional belief that their spouse or partner is unfaithful with little or any proof to back up their claim
• It is associated with alcohol abuse, psychosis and right frontal lobe damage

De Clerambault's syndrome

• De Clerambault's syndrome, otherwise known as erotomania, is a delusional disorder in which the patient has a specific, fixed, false belief that someone else is in love with them
• The patient is usually a woman and the person they are fixated upon is usually of a higher social status, despite only a brief or non-existent acquaintance
• This is not normally any unusual behaviour or hallucinations accompanying the delusion