8. Charles Bonnet syndrome

Ben Rodgers

Charles Bonnet syndrome (CBS) was first described in 1769 when he described hallucinations in his bright elderly father after cataract surgery. It is a condition characterised by the presence of complex visual hallucinations in patients suffering from acquired visual impairment,1 and occurs in up to 50% of people with age related macular degeneration (ARMD). Hallucinations typically develop hours to days after the loss of vision and may be of an insidious or sudden onset.1 Patients typically maintain intellectual functioning and full or partial insight into the fact that the hallucinations are not real.2

The hallucinations are typically pleasant, although they may sometimes cause the patient distress.1 The hallucinations are said to be extremely vivid and patients may experience a sharp contrast between the clarity of hallucinations and reality. Although there are no stereotyped hallucinations specific to CBS, the most common hallucinations are those of faces, animals and geometric shapes. Interestingly, patients may experience visions of themselves, sometimes at earlier stages in their lives, a phenomenon known as heautoscopia or autoscopia.1

There is often no identifiable trigger and hallucinations can last for anywhere from seconds to hours. The exact pathophysiological mechanism surrounding CBS is not currently known, but there are a number of hypotheses, which include sensory deprivation (e.g. “phantom vision” comparable to phantom limb pain) or perceptual release (i.e. the release of subconscious perceptions into the consciousness secondary to reduced afferent sensory input due to vision loss).1


1. Menon GJ, Rahman I, Menon SJ, Dutton GN. Survey of Ophthalmology. 2003;48(1):58-72. Epub 2003/02/01

2. Pang L. Optometry and vision science: official publication of the American Academy of Optometry. 2016;93(12):1466-78. Epub 2016/08/17.

9. Cotard delusion

Lucy Button

Cotard delusion has become the eponym for a nihilistic delusion.1 The word ‘nihil’ is Latin for ‘nothing’, therefore a nihilistic delusion is a belief in nothingness; either in the context of the patient’s own existence or the future or the world. A Cotard delusion is characterised by a patient’s belief that the self, part of the self or their body, such as their internal organs, are diseased, deceased or are non-existent. Within this description, there is an element of delusional thinking that is hypochondriacal or focuses on immortality.

The delusion has been described as a delirium of negation and is associated with self-loathing and severe depression.2 Jules Cotard, in 1880, described this condition the ‘délire des négations’ as a new form of depression with associated anxiety and an agitated melancholia.3 However, this concept was later disputed and it was suggested that Cotard had observed these symptoms as part of a syndrome consisting of nihilistic, or hypochondriacal delusions with affective symptoms. Cotard’s syndrome is therefore the combination of this delusion with varying degrees of depression, and it has been identified in patients with neurological and more usually with psychiatric disorders1,2,4.

Cotard delusion may manifest or present itself in a patient with a pre-existing mental or neurological health disorder with significant affective symptoms and possibly suicidal ideation with an explanation of their non-existence.5


1. Ramirez-Bermudez J, Aguilar-Venegas LC, Crail-Melendez D, Espinola-Nadurille M, Nente F, Mendez MF. J Neuropsychiatry Clin Neurosci. 2010;22(4):409-16

2. Riggs S, Perry T, Dowben J, Burson R. Vive La France: Perspect Psychiatr Care. 2016

3. Pearn J, Gardner-Thorpe C. Neurology. 2002;58(9):1400-3

4. Berrios GE, Luque R. Acta Psychiatrica Scandinavica. 1995;91(3):185-8

5. Huarcaya-Victoria J, Ledesma-Gastanadui M, Huete-Cordova M. Case Rep Psychiatry. 2016;2016:6968409.

10. Couvade syndrome

Ben Rodgers

Couvade syndrome originates from the Breton/French verb “couver”, which means “to brood or incubate”1 and is applied to rituals practiced by many races and cultures around the world from as early as 60BC, whereby expectant fathers are expected to adhere to strict diet and sexual restrictions or even mimic labour (some of whom have claimed to have felt contractions) while their partners are pregnant.1

In Western culture Couvade syndrome, rather than Couvade ritual, describes the wide range of psychosomatic symptoms, – usually weight gain, loss of appetite, nausea and vomiting, and toothache.1,2 Typically, the symptoms experienced resolve after the birth of the child.2 Couvade syndrome is more common in patients with a previous psychiatric diagnosis of depression or anxiety,2 and appears to be an expression of anxiety and occasionally parturition envy.1


1. Laplante P. Canadian Family Physician Medecin de Famille Canadien. 1991;37:1633-60. Epub 1991/07/01

2. Trethowan W.H., Conlon M.F. The British Journal of Psychiatry. 1965;111(470):57-66.

In Part One, the author of the sections on alcoholic hallucinations and anti NMDA receptor encephalitis was incorrectly listed as George Braham, instead of George Bramham. BJFM would like to apologise for this oversight.


11. De Clerambaults syndrome

George Reid

Known also as Erotomania, de Clerambaults syndrome is a recognised delusional disorder that describes the false belief in which a deluded individual believes that a person who is socially and financially attractive, is madly in love with them.1 The syndrome is classically described in women, but cases of affected males and even an equal prevalence has been reported1,2. The subjects of the delusional beliefs are often those with apparent wealth, authority and high social standing. All these attributes are romantically desirable to the delusional person. The delusional individual on the other hand is often a relatively isolated, introverted person, which may encourage the delusions to flourish and grow.2

A number of triggers include high emotions, hormonal disturbance (for example around pregnancy), alcohol and certain medications have been described. However, a strong family history of psychiatric disorders has also been reported.1,2 As time progresses, the delusional person sees signs and messages from their lover which only reaffirms their false beliefs. A song on the radio, a headline in a newspaper, and even an ambiguous facial expression can all contain new meaning for the deluded person and demonstrate the mistaken individual’s perpetual love.2


1. Kennedy N, McDonough M, Kelly B, Berrios GE. Comprehensive Psychiatry. 2002;43(1):1-6

2. Seeman MV. The Psychiatric Quarterly. 2016;87(2):355-64.