This document provides an overview of delusions from multiple perspectives. It defines delusions, describes the types and content of delusions, and explains several theories about the formation and maintenance of delusional beliefs, including psychodynamic, learning, theory of mind, role of emotions, and attributional bias approaches. It also discusses factors such as conviction, extension, bizarreness, and pressure that contribute to delusional severity.

1. A. Samanvithaa
Mphil Clinical Psychology

2. Fixed, relatively immutable, persistent, false
belief with no basis in reality.
A belief held by an individual or group that is
demonstrably false, patently untrue,
impossible, fanciful, or self-deceptive.
A person with delusions – complete certainty
and conviction about their delusory beliefs
and resist arguments and evidence that they
are wrong.

3. A belief indicates an abnormality in the
affected person’s content of thought.
The false belief is not accounted for by the
person’s cultural or religious background or
his or her level of intelligence.
The key feature – the degree to which the
person is convinced that the belief is true.
Overvalued ideas – unreasonable ideas that
a person holds, but the affected person has
at least some level of doubt as to its
truthfulness.

4.  May be present in any of the following mental
disorders:
• Psychotic disorders
• Bipolar disorder
• Major depressive disorder with psychotic features
• Delirium
• Dementia
 Karl Jaspers was the first to define the 3 main
criteria for a belief to be considered delusional:
• 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)

5. Conrad proposed five stages involved in the
formation of delusions:
• Trema: Delusional mood representing a total change
in the perception of the world
• Apophany: A search for, and the finding of new
meaning for psychological events
• Anastrophy: Heightening of the psychosis
• Consolidation: Forming of a new world or
psychological set based on new meaning
• Residuum: Eventual autistic state.

6. A condition in which an individual displays
one or more delusions for one month or
longer.
Delusional disorder is distinct from
schizophrenia and cannot be diagnosed if a
person meets the criteria for schizophrenia.
If a person has delusional disorder,
functioning is generally not impaired and
behavior is not obviously odd, with the
exception of the delusion.
Can be specified as having bizarre content.

7. Kendler et al., (1983) have proposed several
poorly correlated vectors of delusional
severity:
• Conviction: The degree to which the patient is
convinced of the reality of the delusional beliefs.
• Extension: The degree to which the delusional belief
involves areas of the patient’s life.
• Bizarreness: The degree to which the delusional
belief departs from culturally determined consensual
reality.

8. • Disorganization: The degree to which the delusional
beliefs are internally consistent, logical and
systematized.
• Pressure: The degree to which the patient is
preoccupied and concerned with the expressed
delusional beliefs.
• Affective response: The degree to which the patient’s
emotions are involved with such beliefs.
• Deviant behavior resulting from delusions: Patients
sometimes, but not always, act upon their delusions.

9. Jaspers distinguishes four forms of beliefs:
• Normal belief
• Overvalued idea
• Delusion-like idea (Secondary Delusions)
• Primary delusion
Primary Delusions:
• Delusional mood: Strange, uncanny mood in which
the environment appears to be changed in a
threatening way.
• Delusional perception: Abnormal significance
attached to a real percept without any cause that is
understandable in rational or emotional terms; it is
self-referent, momentous, urgent, of overwhelming
personal significance and of course false.

10. • Delusional memory: Patient recalls as remembered
an event or idea that is clearly delusional in nature,
that is, delusion is retrojected in time. These are
sometimes called retrospective delusions.
• Delusional ideas: Appear abruptly in the patient’s
mind, are fully elaborated, and unheralded by any
related thoughts.
• Delusional awareness: an experience which is not
sensory in nature, in which ideas or events take on
an extreme vividness as if they had additional reality.

11.  Erotomanic: An individual believes that a
person, usually of higher social standing, is in
love with him or her.
 Grandiose: An individual believes that he or
she has some great but unrecognized talent or
insight, a special identity, knowledge, power,
self-worth, or relationship with someone famous
or with God.
 Jealous: An individual believes that his or her
partner has been unfaithful.
 Persecutory: An individual believes that he or
she is being cheated, spied on, drugged,
followed, slandered, or somehow mistreated.

12.  Somatic: An individual believes that he or she
is experiencing physical sensations or bodily
dysfunctions, such as foul odors or insects
crawling on or under the skin, or is suffering
from a general medical condition or defect.
 Mixed: An individual exhibits delusions that are
characterized by more than one of the above
types, but no one theme dominates.
 Unspecified: An individual's delusions do not
fall into the described categories or cannot be
clearly determined.

13.  Religious delusions: Not caused by excessive
religious belief, nor by the wrong doing which
the patient attributes as cause, but they simply
accentuate that when a person becomes
mentally ill his delusions reflect his predominant
interests and concerns.
 Delusions of guilt and unworthiness:
Individuals believe that they are bad or evil
persons and have ruined their family. They may
claim to have committed an unpardonable sin
and insist that they will rot in hell for this.

14. Delusions of negation/nihilistic delusions:
This is a false belief that one does not exist
or has become deceased. Reverse of
grandiose delusions.
Delusion of control: This is a false belief
that another person, group of people, or
external force controls ones general
thoughts, feelings, impulses, or behavior.
Delusion of poverty: The person strongly
believes that he is financially incapacitated.

15. Delusion of reference: The person falsely
believes that insignificant remarks, events, or
objects in ones environment have personal
meaning or significance.
Delusion of mind being read: The false
belief that other people can know ones
thoughts.

16. Psychodynamic theory
Learning theory
Theory of mind
The role of emotions
Probabilistic reasoning bias
Theory of attributional bias
Multifactorial model

17.  The result of a conflict between psychological
agencies, the id, ego, and super-ego.
 Delusion is seen as a personal unconscious
inner state or conflict which is turned outwards
and attributed to the external world.
 Freud (1911) proposed that delusion formation
involving denial, contradiction and projection of
repressed homosexual impulses that break out
from unconscious.
 He considered that latent homosexual
tendencies especially formed the basis of
paranoid delusions.

18. Later, psychoanalytical authors gave up this
very narrow hypothesis and suggested that
delusions might be a compensation for any—
i.e. not necessarily sexuality-related—kind of
mental weakness, e.g. lack of self-
confidence, chronic anxiety or identity
disturbances.
This concept in a way resembles Alfred
Adler’s theory of individual psychology.

19. Learning theorists have tried to explain
delusions in terms of avoidance response,
arising specially from fear of interpersonal
encounter.

20. The capacity of attributing mental states such
as intentions, knowledge, beliefs, thinking
and willing to oneself as well as to others.
This capacity allows us to predict the
behavior of others.
E.g., delusions of reference can be
explained, at least in good part, by the
patients’ inability to put themselves in another
person’s place and thus correctly assess their
behavior and intentions.

21. Thought insertion and ideations of control by
others can be traced back to dysfunctional
monitoring of one’s own intentions and
actions.
Hence, thoughts enter the patient’s
consciousness without his or her awareness
of any intention to initiate these thoughts.

22. Delusions driven by underlying affect (mood
congruent) may differ neurocognitively from
those which have no such connection (mood
incongruent).
Specific delusion-related autobiographical
memory contents may be resistant to normal
forgetting processes, and so can escalate
into continuous biased recall of mood
congruent memories and beliefs.

23. Regarding threat and aversive response,
identification of emotionally weighted stimuli
relevant to delusions of persecution has been
associated with activation of the amygdala
and the anterior insula.
Limbic-mediated inappropriate conjunction of
affective tone to memories of imaginary
events could impair reality monitoring and
lead to delusions by adding misleading
contextual information

24.  It assumes that the probability-based decision-
making process in delusional individuals
requires less information than that of healthy
individuals, causing them to jump to
conclusions, which is neither a function of
impulsive decision-making nor a consequence of
memory deficit.
 Deluded patients are not deluded about
everything and there may be no global deficit in
reasoning abilities.
 The findings in reasoning abilities in delusional
patients are only subtle and one might question
the strength of their causality in delusional
thinking.

25. Negative events that could potentially
threaten the self-esteem are attributed to
others (externalized causal attribution) so as
to avoid a discrepancy between the ideal self
and the self that is as it is experienced.
An extreme form of a self-serving attributional
style should explain the formation of
delusional beliefs, at least in cases where the
delusional network is based on ideas of
persecution, without any co-occurring
perceptual or experiential anomaly.

26. During the course of illness, the preferential
encoding and recall of delusion-sensitive
material can be assumed to continually
reinforce and propagate the delusional belief.

27.  The emergence of symptoms assumed to depend
upon an interaction between vulnerability and stress.
 The formation of delusion begins with a precipitator
such as life event, stressful situations, drug use
leading to arousal and sleep disturbance.
 This often occurs against the backdrop of long-term
anxiety and depression.
 The arousal will initiate inner outer confusion causing
anomalous experiences as voices, actions as
unintended or perceptual anomalies which will turn on
a drive for a search for meaning, leading to selection
of explanation in the form of delusional belief.

28.  Neuropsychological examinations will yield clues
to subtle brain dysfunctions in delusional
patients.
 Maher [54] was one of the first to suspect
neurocognitive dysfunctions in delusional
patients.
 In his theory of ‘perceptive-cognitive anomalies’,
he stressed a neuropsychological causality by
assuming disorders of basic cognitive
processing (e.g., losses in perception and
attentiveness) to underlie delusional disorders.

29. More recent neuropsychological studies show
that subjects with ‘pure’ delusions tend not to
show any severe neuropsychological
dysfunctions.
Delusional disorders are associated only with
slight cognitive impairments, if any, as
delusions require an intact neurocognitive
system.

30.  Kiran, C., & Chaudhury, S. (2009 ). Understanding
delusions.Industrial Psychiatry Journal,18(1)(Jan-
Jun), 3-18. doi: 10.4103/0972-6748.57851
 Kunert, H. J., Norra, C., & Hoff, P. (2007). Theories of
Delusional Disorders.Psychopathology,40, 191-202.
doi:10.1159/000100367
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC30166
95/
 https://www.psychologytoday.com/blog/sideways-
view/201506/the-psychology-delusions
 https://www.psychologytoday.com/conditions/delusion
al-disorder
 https://www.slideshare.net/LynGeorgy/delusions-
theories