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Schizophrenia Explanations (Biological Explanations (Dopamine (Initial…

- - - - Neurotransmitter
      - Helps to control the brain’s reward and pleasure centres
      - Helps to regulate movement, attention, perception and emotional responses
    - - Initial concept = an increase in Da lead to positive symptoms of SZ
      - Based on the concept that messages from neurons that transmit Da fire too easily/too often or too many D2 receptors
      - Da neurons play key role in guiding attention, so disturbances in this process may well lead to the problems relating to attention, perception and thoughts found in people with SZ
      - Based on the sig amount of evidence demonstrating the occurrence of amphetamine-induced psychosis
      - Griffith = induced psychosis in a group of non-SZ volunteers - administered doses of dextroamphetamine (increasing Da levels, Da agonist), resulted in an abrupt onset on SZ positive symptoms
    - - Tech and research advanced, revealed different subtypes of Da receptor sites (D1-D5) in the cerebral cortex and limbic system
      - Recent research = antipsychotic drugs affect D2 receptors and reduce positive symptoms leading to a revised hypothesis (more in depth understanding)
      - Cole = controlled research investigating effectiveness of APs (phenothiazines)
      - Found 75% of patients in drug condition improved, 25% in placebo condition improved
      - Supports impact of altering Da levels on reducing symptoms which suggests Da levels are implicated in causing symptoms
    - - One Da pathway in brain = MLP
      - Carries signals from VTA to NAc where D2 receptors are located
      - Too much Da (hyperfunction) from neurons that fire too quick/often, cause overstimulation and ultimately lead to positive symptoms of SZ (hallucinations/delusions)
      - Supported by the treatment of SZ through APs which reduce dopaminergic transmission and activity in this pathway and reduce positive symptoms
    - - Da pathway
      - Carries signals from VTA to frontal lobe where D1 receptors are located
      - Reported that too little Da (hypofunction) in this area of the brain have been associated with individuals who have SZ symptoms (cognitive impairments and negative symptoms - Davis) as this pathway is vital in emotional responses, motivation, cognition and motor function
  - - - Cavities in the brain
      - Produce cerebrospinal fluid that provides protection and buoyancy for the brain and spine and provides nutrients and chemical stability for the brain
      - We have 4 - 2 lateral ventricles, 3rd ventricle and 4th ventricle
    - - Some individuals with SZ = larger lateral and 3rd ventricle
      - Torrey et al = used brain scans, found on average the ventricles of people with SZ were 15% bigger than normal
      - SZ with enlarged ventricles = tend to display more negative symptoms than positive and have greater cognitive disturbances
      - Possible that the increased ventricle size have negative consequences for function in these localised areas
      - The lateral ventricles are situated near cortical structures involved in language processing which could lead to negative symptoms such as alogia
- - - - Freud = individuals with SZ are fixated at oral stage of psychosexual development
      - Fixation due to frustration or trauma from a cold/unresponsive mother
      - Results in a weak/non existent ego that struggles to deal with anxiety/stress so resorts to ego defence mechanisms
    - - Argued that people with SZ regress back to the oral stage when faced with stress/anxiety as this is the point at which they are fixated
      - As the oral stage is pre ego, when regressing back to here, the individual has no sense of reality (as the ego is based on the reality principle) and the id is given free reign
      - Argued SZ symptoms are just the unchecked activities of the id (eg. delusions of grandeur/visual hallucinations due to the id being prone to fantasy)
      - When the ego attempts to take back control, this can result in auditory hallucinations
    - - Frieda Fromm Reichman
      - Proposes that the mothers of SZ individuals have specific characteristics that causes SZ
        
        Overprotective
        
        Controlling
        
        Distant
        
        Rejecting
      - The mother being too overprotective stifles the child’s emotional development
      - Emotional distance deprives the child of emotional security
      - Leaves individual vulnerable when faced with stress
      - SZ occurs due to child being confused/distrustful of others leading to delusions of persecution and paranoid delusions
  - - - Can process thoughts in rational/irrational way
      - Trigger for hallucination
      - SZ individuals have a faulty interpretation of the hallucination (eg. the devil is talking to me)
      - Faulty interpretation = starting point for other SZ symptoms
      - Faulty interpretation = vicious cycle
        
        Social withdrawal (-ve)
        
        Feelings of sadness/shame/fear
        
        Voices become more critical (delusions of persecution/self harm/+ve)
        
        Triggers more hallucinations
    - - 2 types of thought:
        
        Preconscious thought (without awareness)
        
        Conscious thought (with awareness)
      - Typical person:
        
        Preconscious filters important info into conscious thought and filters unimportant info out of conscious thought
      - SZ person:
        
        Preconscious filter does not exist so therefore all stimuli from environment enters conscious thought - think everything is important and needs a reaction
        
        Conscious thought is overloaded leading to delusions/hallucinations/disorganised speech and thinking/alogia
- - - - 2 types of comms - verbal/non verbal
      - SZ = conflicting messages - one message cancels out other
      - Leads to a confused child who fails to create a sense of reality
      - Berger
        
        Retrospective study
        
        Questionnaire
        
        30 double bind statements, ppts asked to rate on a 4 point scale in terms of how frequently they recalled their mothers using such statements
        
        20 SZ ppts consistently reported higher incidences than the control group of 40 college students
    - - High EE = constantly expressing negative emotions
      - High EE environment = stressful, can trigger psychosis or relapse
      - High EE environments:
        
        Critical comments (you are so lazy)
        
        Hostility
        
        Overinvolvement
        
        Lack of warmth
      - Vaughn and Leff
        
        Interviews over an 18 month period
        
        69 SZs (aged 17-39) who had been discharged from hospital treatment back to family home
        
        53% of SZs with a high EE family relapsed
        
        12% with low EE family relapsed
  - - - Higher rates of diagnosis in urban areas than rural
      - Singh = urbanicity has a 3x greater effect on the development of SZ than genes
      - Faris & Dunham = found higher rates of SZ in densely populated inner Chicago than less populated outskirts
      - Van Os = identified factors of urban living that may contribute to the development of SZ:
        
        Poverty - stressful trying to provide
        
        Pollution - hampers brain development in children and adolescents
    - - EMs have higher diagnosis rates than white people
      - Thought to be due to migration
      - Migration = adaptation, marginalisation and discrimination = stress
      - Stress = psychosis
      - Cochrane and Sashidharan = black Afro-Caribbean male immigrants are 7x more likely to be diagnosed than British white people
      - Highest rates of psychosis = Greenlanders in Denmark