Delusions are defined as fixed beliefs that are firmly held despite clear proof to the contrary. They are categorized as bizarre, non-bizarre, mood-congruent, or mood-neutral. Common delusional themes include control, jealousy, guilt, reference, and grandeur. Biological, psychological, and cognitive theories attempt to explain delusion formation, with factors including brain abnormalities, emotions, perception, and biases in attention and reasoning. Delusions may arise from errors in reasoning about the mental states of others.

1. DELUSIONS -
THEORIES
Presented by- Lyn Elsa Georgy

2. definition
 Karl Jaspers was the first to define the three
main criteria for a belief to be considered
delusional in his 1913 book General
Psychopathology. These criteria are:
 certainty (held with absolute conviction)
 incorrigibility (not changeable by compelling
counterargument or proof to the contrary)
 impossibility or falsity of content (implausible,
bizarre or patently untrue)

3. Delusions are categorized into four
different groups
 Bizarre delusion: A delusion that is very strange and
completely implausible; an example of a bizarre delusion
would be that aliens have removed the affected person's
brain.
 Non-bizarre delusion: A delusion that, though false, is at
least possible, e.g., the affected person mistakenly believes
that he is under constant police surveillance.
 Mood-congruent delusion: Any delusion with content
consistent with either a depressive or manic state, e.g., a
depressed person believes that news anchors on television
highly disapprove of him, or a person in a manic state might
believe he is a powerful deity.
 Mood-neutral delusion: A delusion that does not relate to
the sufferer's emotional state; for example, a belief that an
extra limb is growing out of the back of one's head is neutral
to either depression or manic.

4. Themes
 Delusion of control: This is a false belief that another
person, group of people, or external force controls one's
general thoughts, feelings, impulses, or behavior.
 Nihilistic delusion: This is a false belief that one does
not exist or has become deceased.
 Delusional jealousy (or delusion of infidelity): A
person with this delusion falsely believes that a person
is lying to them or that a spouse or lover is having an
affair, with no proof to back up their claim.
 Delusion of guilt or sin (or delusion of self-
accusation): This is a false feeling of remorse or guilt
of delusional intensity.

5.  Delusion of mind being read: The false belief that other people can know
one's thoughts.
 Delusion of reference: The person falsely believes that insignificant
remarks, events, or objects in one's environment have personal meaning or
significance.
 Erotomania : A delusion where someone believes another person is in love
with them.
 Religious delusion: Any delusion with a religious or spiritual content.
These may be combined with other delusions, such as grandiose delusions
(the belief that the affected person is a god, or chosen to act as a god, for
example).
 Somatic delusion: A delusion whose content pertains to bodily functioning,
bodily sensations, or physical appearance. Usually the false belief is that
the body is somehow diseased, abnormal, or changed—for example,
infested with parasites.
 Delusion of poverty: The person strongly believes that he is financially
incapacitated. Although this type of delusion is less common now, it was

6. Theories

7. Delusion formation- factors
 Disorders of brain functioning
 Influences of personality and temperament
 Self esteem
 Role of affect
 Resultant of Perceptual disturbances
 Result of depersonalization
 Cognitive overload, styles
 - Brockington, 1991

8. Biological theories
 Damage to frontal lobes (pre) – responsible for
self analysis, control, executive functions can
precipitate delusions- Stuss and Buss (1986,
1990).
 Increased dopamine can result in delusional
and hallucinatory behavior ( Sherer, Kumor,
Cone & Jaffe, 1988)
 Left temporal brain lesions-correlated with
hallucinatory and delusional states. Cutting,
1985)

9. Freudian hypothesis
 Basic hypothesis- delusions stem from repressed
homosexual tendencies. Based on his case study reviews of
judge Schreber.
 The basic proposition is that ― I a man cannot love a man ,
therefore its repressed, however it manages to find a way out
of the unconscious after some distortions, ultimately in the
form of delusions-
 Propositions in the unconscious-
 Delusions of persecution- I hate him, he hates me, hence he
is after me.
 Delusions of love- I love her and she loves me.
 Delusions of jealousy- I do not love him, she loves him and
he love her.
 Delusions of grandeur- I do not love him, I love me, and
others love me.

10.  Griesinger (1845)- delusions of nihilism-
subjective within is misplaced on to outside
things. Everything is dead.
 Delusions of guilt, unworthiness, religious
delusions predominantly seen as secondary to
depressive mood. Higgins,(1990).

11. Delusions and attention
 Psychotic patients also exhibit similar
unhelpful cognitive styles like patients with
neurotic disorders like anxiety and depression.
For example their delusional beliefs may be
based on the operation of catastrophisation of
bodily sensations, selective attention to
threatening stimuli, (or a all or none thinking
style).
 Differences in paranoid vs non paranoid
schizophrenics (Magaro, 1980); former
extensive scanners of environment, latter poor.

12. Delusions and perception
 Pavlov (1934) first proponent that perceptual
anomalies can cause delusions(reference and of
being controlled), the explanation he gave was that a
pathological inertness of cells in the sensory cortex,
which results in hyperarousal of other surrounding
cells, which causes irrelevant ideas to enter the
conscious, acc to pavlov, delusion is a reflection on
these irrelevant ideas.
 Kays (1972), Cooper and Potter(1976)- higher
incidences of perceptual difficulties in visual and
auditory modality in paranoid patients, when

13. Delusions and emotions,
motivation
 Bleuler (1906) suggested emotions weaken
normal associations between normal thoughts
and leads to the development of schizophrenic
patients, whereas in paranoia, emotions lead
to the pathological adherence to the delusion.
 In contrast Jaspers and Scheinder
differentiated between primary and secondary
delusions based on the affective component.

14. Cognitive styles and processes
1. Jumping to conclusions- A number of research
studies that people with delusions have a
tendency to seek relatively less information
before reaching a conclusion, this has been
more specifically described as ― Data Gathering
Bias‖ –( Garety and Freeman, 1999)
2. Attribution bias- people with persecutory
delusions generally tend to blame other people
(rather than by chance than by themselves) for
bad events happening to them, which is an
exaggeration of the self serving bias that
normals usually show. (Bentall, 1996)

15. Theory of Mind (ToM)/ meta
representations
 Theory of Mind is the ability - displayed by adult humans - of making
inferences about the content of other people‘s minds.
 It has recently been noted that the subject matter of Delusional
disorders is distinctive, since the false beliefs are ‗social‘ in content,
and typically concerned with the assumed dispositions, motivations
and intentions (DMIs) of other people. For this reason, Delusional
disorders have been labelled ‗Theory of Mind‘ delusions, because
they seem to involve inferences (or theories) about what is going on
in the minds of other people (Charlton & McClelland, 1999).
 For example the commonest types of Delusions of jealousy over
sexual infidelity and those in which there is a false belief of
persecution. It has been suggested that these delusions derive from
errors of inference relating to the contents of other people‘s minds.
 Since Delusional disorder is related to reasoning about the
dispositions, motivations and intentions of other people, the
mechanism by which such reasoning is performed in humans
requires consideration.

16. Sexual jealousy in evolutionary
context
 Jealousy in men can be seen as an evolved psychological adaptation that
operates to reduce the chance of sexual infidelity in a partner, and reduce the
chance of misdirected investment (even the act of mating typically requires
substantial investment of resources, and loss of the opportunity to invest these
in courting other mates; Buss, 1994).
 Jealousy in women is significantly different since female mammals do not
suffer from uncertainty as to the identity of their offspring, and sexual infidelity
per se is not a problem. The problem for a female is to secure investment to
help in rearing offspring, and jealousy is primarily concerned with ensuring tha
the male partner directs his investment efforts towards the woman‘s own
offspring. So female jealousy is less concerned with the act of sexual infidelity
and more with the danger of a male partner transferring his affections (and
resources) to another female (Wiederman & Allgeier, 1993; Buss, 1994).
 Hence selection pressures have led to different cues that stimulate the emotion
of jealousy in men and women: men primarily fear physical infidelity (the
partner having sexual intercourse with another man) while women primarily
fear emotional infidelity (the partner falling in love with another woman)
(Townsend, 1995; Geary et al, 1995; Mullen & Martin, 1994).

17.  Enoch (1991) regards th nature of the
relationship between the partners as a key
aspect, the deluded partner is very attached to
emotionally dependent and may have a
misplaced sense of owning that person
completely. The victim is much more sexually
attractive that the deluded.

18. References-
 Smith, L., Nathan, P., Juniper, U., Kingsep, P.,
& Lim, L. (2003). Cognitive Behavioral Therapy
for psychotic symptoms: a treatment manual.
Perth : Australia.
 Adams, H.E., & Sutker, P.B. (2001).
Comprehensive handbook of psychopathology.
Gulf Professional Publishing.
 Sims, A. C. P. (2002). Symptoms in the mind.
Elsevier Science Ltd: London.