schizophrenia Flashcards
what are positive symptoms?
additional experiences to those of a ordinary person
- hallucination and delusions
what are negative symptoms?
the loss of usual abilities and experiences
- avolition
- speech poverty
what are hallucinations?
sensory experiences
- hearing voices
- seeing things that arent there
what are delusions?
irrational beliefs
- e.g. thinking you’re related to a famous historical figure
- make people behave in ways that seem normal to them but bizarre to others
what is avolition?
finding it difficult to begin or keep up with goal directed activity
Lack of motivation
- e.g in hygiene or grooming
what is speech poverty?
a reduction in the amount or quality of speech in a person
what is a strength of diagnosis and classification?
it has high reliability
- high inter rater reliability (+97)
- high test retest reliability (+92)
what are limitations of diagnosis and classification?
Co-morbidity
- Buckley et al found that around half of those diagnosed with Sz also had depression or substance abuse
Gender Bias
- Men more likely to get diagnosed to women - 1.4:1 ratio
- women may not be getting diagnosed or the treatment necessary
Culture Bias
- British African-Caribbean 10x more likely to get diagnosed with Sz
- Haitians believe hearing voices are their ancestors
what are the genetic explanations for Sz?
- Family studies
- Candidate genes
- Role of mutation
what is family studies?
having a family member with Sz increase the chance of developing it
- 43% for identical twin
- 9% for sibling
what is candidate genes?
how faulty genes could cause schizophrenia
- most likely genes coding for Dopamine
- Ripke et al found 108 genetic combinations increasing vulnerability to Sz
what is the role of mutation?
a mutation in parental DNA can cause Sz
- can come from radiation, poison or viral infection
- evidence comes from correlation of Paternal age and Risk of Schizophrenia
Strength of Genetic Approach
Evidence
- Gottesman large scale family study found someone with an Sz aunt has a 2% chance, Sz sibling 9%, Sz identical twin 43%…
- Tienari et al found that biological children of a parent with Sz still have a high chance even when growing up with adoptive family
- Hilke et al found a correlation of 33% in identical twins and 7% in non-identical twins
Limitations of Genetic approach
Environmental factors
- risks in birth complications (Morgan et al)
- Cannabis smoking in teenage years (Di Forti et al)
- Childhood trauma - 67% correlation (Morkved)
what is Neural explanations to Sz?
- original dopamine hypothesis
- updated dopamine hypothesis
what is the original dopamine hypothesis?
- drugs treating Sz caused symptoms similar to Parkinsons - a condition associated with low DA levels
- Schizophrenia may be due to high DA levels in subcortical areas of the brain (hyperdopaminergia)
- e.g. high levels of DA receptors in Brocas area causing auditory hallucinations
what is the updated dopamine hypothesis
Davis proposed the idea of abnormally low DA receptors in the brain (hypodopaminergia)
- it has been suggested that Cortical hypodopaminergia leads to Subcortical hyperdopaminergia
- abnormal DA function origins in genetic variation and early experiences of stress (Howes)
strength of the neural explaination
Evidence supporting
- Amphetamines increase DA Amphetamines worsen symptoms of those with Sz and can induce it in those without (Curran et al)
- Antipsychotics reduce DA and also reduce intensity of symptoms (Tauscher et al)
limitation of the neural explaination
Glutamate
- post mortem brain scans have shown high levels of glutamate in those with Sz
- suggests the role of other neurotransmitters
what is Family Dysfunction?
- the Schizophrenogenic Mother
- Double-bind Theory
- Expressed Emotion
what is the Schizophrenogenic mother?
- Fromm-Reichmann proposed idea
- meaning schizophrenia causing mother
- many of their patients talked of a particular type of parent
- the mother is cold, controlling and rejecting - leading to family climate of tensions and secrecy
- leads to distrust - develops in delusions and ultimately schizophrenia
what is Double-Bind theory?
- Bateson suggested if a developing child often find themselves trapped in situations where they fear doing the wrong thing, but receive mixed messages and can comment on the unfairness or seek clarification
- When they get it ‘wrong’ they are punished by the withdrawal of love
- Makes world seem confusing and dangerous
- often leads to dysfunctional thinking and paranoid delusions
what is Expressed Emotion?
the level of emotion expressed to a person with Sz by their carers
- verbal criticism often accompanied by violence
- hostility - e.g. anger and rejection
- Emotional over involvement - e.g. needless self-sacrifice
this causes stress in the individual and is often a cause of relapse but can also be a trigger for a vulnerable person
Strength of Family Dysfunction
Research Support
- Read et al found that those with Sz are disproportionately more likely to have insecure attachments (usually type C or D)
- Read et al also found 69% of men and 59% of women with Sz have a history of physical or sexual abuse
- Morkved et al also found that 67% of people with Sz had childhood trauma