PSYCHOLOGY &
ABNORMALITY
SCHIZOPHRENIC AND PSYCHOTIC DISORDERS
Characteristics of schizophrenia spectrum and
psychotic disorders.
De nitions, examples and case studies of schizophrenia and psychotic
disorders
Schizophrenia - is a sever type of psychotic disorder that a ects all aspects of a person's thoughts,
emotions and actions.
Psychotic disorders - this involves a major break from reality in which individuals perceive there
world in a way di erent from how others perceive it.
The DSM-5 (diagnostic and statistical manual) de ne schizophrenic and psychotic disorders as
sharing the following "positive" and "negative" symptoms:
Positive symptoms (they add behaviors):
• Delusions: belief that aren't based on reality. Eg: believing other people are trying to harm you.
Firmly held irrational beliefs that have no basis in reality.
• Hallucinations: sensory experiences that may involve seeing and hearing things that do not
exist. Eg: hearing voices
• Catatonic behavior: unresponsive to the environment and remain rigid in awkward position.
• disorganized thoughts: mixed up and racing thoughts. Speech might be jumbled and di cult to
understand
Negative symptoms (they worsen or take away behaviors):
• Speech poverty: loss of speech or lack of typical facial expressions. Reduced frequency and
quality of speech.
• Avolition: lack of purposeful, willed behavior. Di culty or inability to start with goal-directed
behavior. Leads usually to lower motivation, lower activity levels.
The main types of schizophrenia spectrum and psychotic disorders are the following:
1
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, 1. Schizotypal personality: Di culty developing meaningful relationships, showing extreme coldness
and at a ect.
2. Substance / medication: Induced psychotic disorder, caused by prolonged excessive alcohol use
or withdrawal from certain drug substances.
3. Schizoa ective disorder (SAD): Features from both schizophrenia and a mood disorder (bipolar)
4. Delusional disorder: Persistent delusions, but the su erers usually lead to a normal life
5. Schizophrenia: Show at least one symptom present for at least 6 months and cannot be attributed
to the use of substance or medication
6. Psychotic disorder due to other medical condition:
7. Catatonia: symptoms that usually involve a lack of movement and communication, and also can
include agitation, confusion, and restlessness
Schizophrenia and delusional disorder
Delusional disorders are characterized by persistent delusions, they have a normal life compared
with schizophrenic individuals. It also excludes those su ering other psychotic symptoms
(hallucinations, disorganized speech, catatonia or negative symptoms)
There are several types of delusional disorders:
• Erotomanic: believe another person is in love with them.
• Grandiose: Believe to have an over-in ated sense of worth, power, knowledge or identity within a skill
or status.
• Jealous: believe that partner is unfaithful
• Persecutory: Believe they are being conspired against or pursued by others who intend to harm them
• Bizarre: Delusions beyond the realm of occurrence. Eg: believing one's internal organs have been
removed and replaced by others, without scars.
• Non-bizarre: these have the potential to be true or possible. Eg: jealousy delusion
To be diagnosed with a delusional disorder, the patient must have experienced symptoms (stated in
the DSM-5) for one month or longer. These symptoms should be unrelated to substance use or other
medical disorder.
Symptom assessment using virtual reality (Freeman 2008)
Freeman explores the potential for the use of virtual reality can eliminate the di culties in interpreting
symptoms and developing treatment.
2
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, VR has been used successfully to treat other disorders such as phobias, they do so by presenting
di erent social environments to the participants.
Symptom assessment:
Normally, symptom assessment happens with an interview and a patient discussing in a clinical room
their behavior in past weeks. This has several issues:
• Relies on the patient answering truthfully always
• Relies on patient discussing personal circumstances which does not rule out that beliefs of
persecution are unfounded.
VR can be used for symptom assessment, this can be done by presenting the patient to several
arti cial social behaviors, this ensures the following:
• Assessment will be novel and standardized
• Ensures paranoid thoughts and behaviors are genuine as social situation is arti cial
Research experiment:
The Research was conducted in the following way:
• two scenes; a library and a underground train in presence of neutral avatars
• 200 students of a non-clinical population
• Prior to the test a large number of validated measurement tools where used to pro le each individuals
level of paranoid thinking, emotional distress and other traits (16 item green et al paranoid thoughts
scale GPTS).
• Participants where placed in the virtual environment
• Afterwards, measures of persecutory thinking, visual analogue rating scales and assessment of
immersion in virtual environment.
Freeman came with the following results:
• Those scoring high in the 'GPTS' showed high levels of persecutory ideation (others try to harm you or
you are at ill-risk) → More likely to make comments such as "lady sitting down next to me laughed at
me when I walked past" rather than positive/neutral comments
• Individuals who experience auditory hallucinations in real world, also experienced them in VR.
Evaluation of Freeman's experiment:
Strengths of the research:
• Fairly large sample
• Standardized VR approach, increasing the reliability of measurements
• Both quantitative and qualitative data
3
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, • Researchers have more control over any possible confounding variables as scene is in VR, increases
internal validity
Weaknesses of the research:
• Did not represent clinical population
• Simulated environment reduced the ecological validity
• Relies still on self-reports can lead to response bias
Issues & Debates:
• Cultural bias: it relies on cultural norms to western cultures, some cultures are more tolerant in relation
to hearing voices. Also norms such as levels of eye contact and space will vary amongst cultures
• Application to real life: it can potentially be used to asses p's symptoms, and also for treatment
strategies.
Explanations of schizophrenia and delusional disorder
Genetic (Gottesman and Shields 1972)
Gottesman and Shields carried out a twin study research into the genetic inheritance of
schizophrenia.
General symptom of schizophrenia is psychosis (series of function abnormalities such as sensory
disfunction and memory impairment) this symptoms have genetic origins "endophenotypes"
therefore it can be claimed that schizophrenic symptoms are identi able genetic markers which
may be inherited.
Concordance rate: the presence of a particular trait or disorder in both individuals within a set of
twins
Gottesman found a much higher concordance rate in MZ twins (48%) than in DZ twins (17%)
Gottesman and shields experiment's procedure:
• 467 twins Maudsley hospital London (1948-1964)
• Gathered data of 57 twins (24 MZ and 33 DZ) which at least one of twins diagnosed with
schizophrenia.
• Twins where identi ed as MZ or DZ using blood group, ngerprint analysis, visual tests, data collection
(hospital notes and case studies) and tape recordings of interviews.
Gottesman's ndings:
• 58% of MZ twins shared schizophrenic status
• 9% if DZ twins shared schizophrenic status
4
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ABNORMALITY
SCHIZOPHRENIC AND PSYCHOTIC DISORDERS
Characteristics of schizophrenia spectrum and
psychotic disorders.
De nitions, examples and case studies of schizophrenia and psychotic
disorders
Schizophrenia - is a sever type of psychotic disorder that a ects all aspects of a person's thoughts,
emotions and actions.
Psychotic disorders - this involves a major break from reality in which individuals perceive there
world in a way di erent from how others perceive it.
The DSM-5 (diagnostic and statistical manual) de ne schizophrenic and psychotic disorders as
sharing the following "positive" and "negative" symptoms:
Positive symptoms (they add behaviors):
• Delusions: belief that aren't based on reality. Eg: believing other people are trying to harm you.
Firmly held irrational beliefs that have no basis in reality.
• Hallucinations: sensory experiences that may involve seeing and hearing things that do not
exist. Eg: hearing voices
• Catatonic behavior: unresponsive to the environment and remain rigid in awkward position.
• disorganized thoughts: mixed up and racing thoughts. Speech might be jumbled and di cult to
understand
Negative symptoms (they worsen or take away behaviors):
• Speech poverty: loss of speech or lack of typical facial expressions. Reduced frequency and
quality of speech.
• Avolition: lack of purposeful, willed behavior. Di culty or inability to start with goal-directed
behavior. Leads usually to lower motivation, lower activity levels.
The main types of schizophrenia spectrum and psychotic disorders are the following:
1
fi ff ffi fi ff ffi
, 1. Schizotypal personality: Di culty developing meaningful relationships, showing extreme coldness
and at a ect.
2. Substance / medication: Induced psychotic disorder, caused by prolonged excessive alcohol use
or withdrawal from certain drug substances.
3. Schizoa ective disorder (SAD): Features from both schizophrenia and a mood disorder (bipolar)
4. Delusional disorder: Persistent delusions, but the su erers usually lead to a normal life
5. Schizophrenia: Show at least one symptom present for at least 6 months and cannot be attributed
to the use of substance or medication
6. Psychotic disorder due to other medical condition:
7. Catatonia: symptoms that usually involve a lack of movement and communication, and also can
include agitation, confusion, and restlessness
Schizophrenia and delusional disorder
Delusional disorders are characterized by persistent delusions, they have a normal life compared
with schizophrenic individuals. It also excludes those su ering other psychotic symptoms
(hallucinations, disorganized speech, catatonia or negative symptoms)
There are several types of delusional disorders:
• Erotomanic: believe another person is in love with them.
• Grandiose: Believe to have an over-in ated sense of worth, power, knowledge or identity within a skill
or status.
• Jealous: believe that partner is unfaithful
• Persecutory: Believe they are being conspired against or pursued by others who intend to harm them
• Bizarre: Delusions beyond the realm of occurrence. Eg: believing one's internal organs have been
removed and replaced by others, without scars.
• Non-bizarre: these have the potential to be true or possible. Eg: jealousy delusion
To be diagnosed with a delusional disorder, the patient must have experienced symptoms (stated in
the DSM-5) for one month or longer. These symptoms should be unrelated to substance use or other
medical disorder.
Symptom assessment using virtual reality (Freeman 2008)
Freeman explores the potential for the use of virtual reality can eliminate the di culties in interpreting
symptoms and developing treatment.
2
fl ffff ffi fl ff ff ffi
, VR has been used successfully to treat other disorders such as phobias, they do so by presenting
di erent social environments to the participants.
Symptom assessment:
Normally, symptom assessment happens with an interview and a patient discussing in a clinical room
their behavior in past weeks. This has several issues:
• Relies on the patient answering truthfully always
• Relies on patient discussing personal circumstances which does not rule out that beliefs of
persecution are unfounded.
VR can be used for symptom assessment, this can be done by presenting the patient to several
arti cial social behaviors, this ensures the following:
• Assessment will be novel and standardized
• Ensures paranoid thoughts and behaviors are genuine as social situation is arti cial
Research experiment:
The Research was conducted in the following way:
• two scenes; a library and a underground train in presence of neutral avatars
• 200 students of a non-clinical population
• Prior to the test a large number of validated measurement tools where used to pro le each individuals
level of paranoid thinking, emotional distress and other traits (16 item green et al paranoid thoughts
scale GPTS).
• Participants where placed in the virtual environment
• Afterwards, measures of persecutory thinking, visual analogue rating scales and assessment of
immersion in virtual environment.
Freeman came with the following results:
• Those scoring high in the 'GPTS' showed high levels of persecutory ideation (others try to harm you or
you are at ill-risk) → More likely to make comments such as "lady sitting down next to me laughed at
me when I walked past" rather than positive/neutral comments
• Individuals who experience auditory hallucinations in real world, also experienced them in VR.
Evaluation of Freeman's experiment:
Strengths of the research:
• Fairly large sample
• Standardized VR approach, increasing the reliability of measurements
• Both quantitative and qualitative data
3
fffi fi fi
, • Researchers have more control over any possible confounding variables as scene is in VR, increases
internal validity
Weaknesses of the research:
• Did not represent clinical population
• Simulated environment reduced the ecological validity
• Relies still on self-reports can lead to response bias
Issues & Debates:
• Cultural bias: it relies on cultural norms to western cultures, some cultures are more tolerant in relation
to hearing voices. Also norms such as levels of eye contact and space will vary amongst cultures
• Application to real life: it can potentially be used to asses p's symptoms, and also for treatment
strategies.
Explanations of schizophrenia and delusional disorder
Genetic (Gottesman and Shields 1972)
Gottesman and Shields carried out a twin study research into the genetic inheritance of
schizophrenia.
General symptom of schizophrenia is psychosis (series of function abnormalities such as sensory
disfunction and memory impairment) this symptoms have genetic origins "endophenotypes"
therefore it can be claimed that schizophrenic symptoms are identi able genetic markers which
may be inherited.
Concordance rate: the presence of a particular trait or disorder in both individuals within a set of
twins
Gottesman found a much higher concordance rate in MZ twins (48%) than in DZ twins (17%)
Gottesman and shields experiment's procedure:
• 467 twins Maudsley hospital London (1948-1964)
• Gathered data of 57 twins (24 MZ and 33 DZ) which at least one of twins diagnosed with
schizophrenia.
• Twins where identi ed as MZ or DZ using blood group, ngerprint analysis, visual tests, data collection
(hospital notes and case studies) and tape recordings of interviews.
Gottesman's ndings:
• 58% of MZ twins shared schizophrenic status
• 9% if DZ twins shared schizophrenic status
4
fi fi fi fi
