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Delusions: a symptom approach (Defining & examples (Do people truly…
Delusions: a symptom approach
Rational beliefs
Hume
Weigh up evidence and evaluate it. Changing beliefs according to said evidence.
Delusions: beliefs
not
based in evidence
Defining & examples
A false belief based on incorrect inference about external realities which is held firmly despite contesting beliefs and lack of proof
Religious beliefs don't count as are accepted by an entire culture
Many delusionary claims are unfalsifiable - so how do we know that they are incorrect?
Though we don't
know
they are false, they are considered delusions if they are bizarre
DSM
Bizarre delusions
"My son was replaced by a CPR dummy"
Non-bizarre delusions
"Gigi Hadid is in love with me"/ delusional jealousy
Do people
truly believe
their own delusions?
Behaviour is often not entirely aligned with the delusion
Sass:
actions are not as would be expected in accordance with belief in delusions
Currie:
delusions are
not
beliefs, but
imaginings
which are misidentified as beliefs
Does a delusion necessarily mean an
incorrect
inference about
external
realities?
No.
Could also be about the
internal e.g.
"I am Jesus"
Prevalence of
religion-related delusions
changes with time and place:
Cook
1-80%
huge variation
Rokeach: the 3 Christs of Ypsilanti
3 patients who each believed they are Jesus
Fought with one another violently
Eventually explained away the others
Symptom Approach & DSM
A sign or feature indicating a disease or disorder
Delusions are a symptom of multiple different disorders in the DSM-5
Whereas, Syndrome Approach = a condition or disease characterised by symptoms
DSM
Positive symptom: additional element not present in the healthy population
Diagnoses may include
Schizophrenia
Delusional Disorder
Brief Psychotic Disorder
Substance or Medication Induced Psychosis
Brain injury etc
Characterisation of syndromes by symptoms is controversial
Cohen
Symptoms may have
different underlying causes and effects
so... might not provide accurate diagnoses
e.g.
Bentall
patients with hallucinations are better at self-monitoring than those with just delusions
Note:
delusions are the belief and hallucinations are the experience, they can occur independently and together
Continuum Approach
Delusions
are
present in the general population, but they are mild and not impairing
Psychotic symptoms are simply the extreme end of the spectrum
Treatment
Pharmacological Treatment
Side effects can be difficult so alternatives are preferable
Weight gain, sexual dysfunction, type 2 diabetes and others :
Evidence that antipsychotics effective in managing delusions
Cognitive Behavioural Therapy
Therapist presents alternative hypotheses to delusions: collaboration and consideration of evidence to support alternatives
Self-persuasion?
Reasoning Biases reveal cognitive dysfunction so CBT justified
Seems effective
Landa
Motivational vs Deficit
M
A coping mechanism which can neutralise/explain negative or strange experiences via a delusion
Delusions are
beneficial
as they protect the person from a negative experience
e.g.
reducing discomfort or confusion
Help make sense of a disturbing experience
Unfalsifiable - if we can't test it then does it have any use?
Some argue that these views are obselete
Ellis:
"tired and outdated"
But perhaps M accounts for specific delusions may be plausible/ justifiable?
McKay
D
Delusions are
dysfunctional
as they create a false sense of reality
A product of dysfunctional thinking/ brain processes
Falsifiable framework
The anomalous experience
Maher:
the locus of the pathology is in the
neuroscience of the experience
e.g.
Capgras delusion
The delusion that a close loved one (like your Mother) is actually an imposter
D
This delusion is caused by maladaptive brain processes
Amygdala
: extreme emotional response leading to high suspiscion
Anomalous experience of faces
Ellis:
Skin response indicates lower familiarity in psychotic group when looking at familiar faces.
Problem with face recognition due to dysfunction in the
Visual Cortex and/or Limbic System
Turner:
Brain surgery in treatment of epilepsy later developed feelings that his Mother wasn't really herself
But not full belief in delusion? So other factor at play -
*Two-factor theory
M
The delusion protects against negative emotional responses or resolves inner conflicts
Enoch:
resolution of ambivalence (conflicting love and hate) towards person
Capgras:
delusion is an attempt to cover forbidden incestuous desires "I want to sleep with her and it's OK because she isn't really my Mother"
Also believed this about aunt, brother and uncle - too much incest to be true?
A bit Freudian... unfalsifiable
Delusion also occurs in relation to pets/ inanimate objects - incest not the root of these.
e.g.
Cotard delusion
The delusion that you are already dead
M
Works as a protective factor against the fear of the inevitable: death - Terror Management Theory
If fear of death is the motivator, why not believe you are invincible/ immortal?
Perhaps motivation is actually fear of unknown after death, not death itself? Or perhaps death and immortality beliefs achieve the same goal so it makes no difference?
D
Global disruption to brain pathways regarding sensory experiences
e.g.
Fregoli delusion
The delusion that people known to the patient follow them in disguise
D
Impaired brain functioning
Ellis
After a stroke, patient claimed that two acquaintances were following her
Davies:
higher emotional response to unfamiliar faces
M
Coping mechanism
e.g.
"My father follows me in disguise" provides comfort if Father is in fact dead -
Collacot
Fails to explain why patients with this delusion might believe that the misidentified strangers have
hostile
intentions
Other Anomalous Experiences leading to Delusions
Mirrored-self misidentification: person in the mirror seen as a stranger
Breen
caused by face processing deficit in brain
Tinnitus ear illness -> 'Bees in the head' delusion
Southard
Deja Vecu
Turner
patient has disrupted recognition systems (Temporal Lobe) which lead to anomalous feelings of familiarity
Maher
says Anomalous experiences are enough to explain delusions
But things like Tinnitus are very common, and not everyone develops 'Bees in the head' delusion?
Deja Vu also common but most people don't delusionally believe that they have
actually
lived the same life more than once
Two-factor theory
1
Anomalous experience
2
Why is this belief adopted and maintained despite implausibility?
Irrational thinking hypothesis: Delusional people are
under-responsive
to evidence
NO!
Some delusions suggest that patients are
Over-responsive
to evidence
e.g.
hear buzzing which sounds like bees (tinnitus) so concretely believe that bees are present
Supported by
'Jumping to conclusions'
evidence that psychosis patients rely too heavily on evidence and don't evaluate evidence rationally, compared to healthy population
Even true when reward offered for accuracy
McKay
Prediction error
expectation and occurrence discrepancy
Corlett
delusions associated with aberrant prediction error signalling - higher response to
unsurprising
events
Suggests increased salience of ordinary, everyday experiences which could lead to feelings of unfamiliarity
Factors
1: Disruption in brain causes anomalous sensory experiences which trigger prediction error signals
2: Excess PES increase salience of experience and cause over-active response