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  • Created by: RobynWeir
  • Created on: 11-06-16 20:37


The extent to which the results are consistent. You can test reliability ility by using

  • Inter-rater reliability - see if more than one other professional diagnoses the patient the same as you.
  • Test Re-test - see the same patient again and see if you diagnose them the same on a different day.

Issues with reliability stem from the vagueness of the classification systems. The ICD = UK. The DSM = USA. Reliability is questioned due to the differences is subtypes, the DSM has 7 while the ICD only has 5. Also, patients must have symptoms for at least 1 month in the ICD and for 6 months in the DSM.

Supported by Becker - 54% agreement between 2 psychiatrics, some inconsistencies were down to human error but mainly the inadequacy of the classification system. Also support by Jakohsen who found a conor dance rate of 98% using the ICD. However, still not 100%. 

Challenged by Nilson who found 81% concordance using DSM and 60% using ICD shows inconsistencies. Also, Seto found schizophrenia is labelled 'intergration disorder' in Japan as it is too hard to apply to people. There is no real agreement whether schizophrenia even exists so cannot be reliable. Fine lines between subtypes - subjective interpretation.

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The extent to which the diagnosis is accurate. Can check validity by:

  • Reliabilty - diagnosis cannot be accurate if it is not consistent. 
  • Predictive validity - if the treatment provided is successful, diagnosis was accurate. 
  • Descriptive validity - all patients with same diagnosis act the same way.

Issues with accuracy is that there are sother many subtypes, it is difficultto be 100% accurate. Diagnosis is based on subjective data from patient whof has lost touch with reality and interpretation by medics. Comorbidity is when patients show symptoms of more than one disorder eggs bipolar.

Supported by Rosenhan who found 7 out of 8 participants were diagnosed after reported one symptom and it took 19 days to convince medics they were healthy. However considered unrealisitic and unethical as they would be labelled for life 'recovered schizophrenics'.

Challenged by stats which show African Americans 2x more likely to be diagnosed than white Africans, their flat affect and alogia could be result of prejudice. Also, undifferentiated schizophrenia showsuch the lack of validity as people are too hard to diagnose so placed here. Stats also show higher rates for lower classes shows subjective nature. 

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Biological explanation - Genetics

General population has 1% chancentre of developing schizophrenia. Kendler shows first degree relatives of schizophrenics are 18 times more at risk. Percentage increases to 40% chance if both parents have the disorder and 48% if an identical twin does. Also use twin studies in this explanation - concordance rates between MZ and DZ twins. Adoption studies are used to separate nature and nurture as the child grows up away from schizophrenic parent. 

Heston supports genetics, found in 47 adoption cases were mothers were schizophrenics, 17% of children went on to develop it which demonstrates the influence of genetics. However, criticised for temporal validity (conducted in 1960s when classification was limited). Also ignores the environment the children grew up in. 17% is still low, 83% didn't develop it.

Supported by quadruplets who all developed it (ignores social influences grew up together).

Adoption studies are criticised for not being random as parents chose children genetically similar to them so run the risk of being similar to their biological parents. Also, genetic theories are considered socially sensitive (blame parents unlike cognitive). Twin studies deemed useless as they grow up in same environment and shared same womb which could've influenced development. Twin studies also contain conflicting research (concordance between 11% - 58%) Finally, no single gene found, questions whether schizophrenia even exists.

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Biological explanation - Biochemistry

Dopamine hypothesis. Dopamine is a neurotransmitter found in the limbic system in the brain. What should happen--- electrical pulse fills a neuron with neurotransmitters  (dopamine) which bind to receptor sites in the synapse. Then MAOA should break down excess neurotransmitters and proceed with the reuptake process. Faults can occurs if receptor sites are too sensitive, receptors sites are faulty (through drugs or genes), MAOA is faulty so excess dopamine is not broken down, reuptake process may not occur or there is just natural over production of dopamine.

Supported by Wong found twice as many receptor sites in schizophrenics. Also, post mortems show excess dopamine or sensitive receptors. However post mortems are bidirectional may have excess dopamine due to schizophrenia. Kessler found elevation of receptor sites in schizophrenics on PET scans. Most ethical, doesn't blame anybody just a natural fault.

Challenged as dopamine is involved in other disorders like depression or bipolar so issue of comorbidity. Also anomalies as not all schizophrenics have excess dopamine. Considered deterministic by ignoring free will, patients have no choice (unlike cognitive) 

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Psychological - cognitive

Cognitive explanation believesays schizophrenia is a result of faulty attention process. Schizophrenics are said to be unable to filter out irrelevant things so become overwhelmed by the demandsame of the environment. Bentall showed that schizophrenics have cognitive bias towards more threatening words in a stoop test. 

Also schizophrenics are said to have a break down of communication which means they cannot develop schemas. Therefore every new situation leads to sensory overload.

Meta representative faults mean schizophrenics have problems self monitoring or keeping track of intentions so thoughts often appear implanted.

Supported by Mcguian who found the larynx is active during claims of hearing voice - hearing own thoughts without realising. Also positive implications -  treatment (CBT) however, can be seen as invasive for schizophrenics.

Challenged as theory is considered bidirectional  (faulty thoughts could be the result of schizophrenia). Also socially sensitive as it blames the individual(counterproductive). Not much research for this explanation-all non falsifiable unlike biology. 

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Psychological - role of the family

Psychodynamic theory argues schizophrenia is a result of family communication. An unstable family is known as a schizophrenogenic family who tend to have high levels of emotional tension, close alliances and are secretive. Also identifies the double bind hypothesis where families give contradicting messages eg "it's for your own good" after giving an insult. This can confuse an individual and alter their view on reality.

Expressed emotion is used in explaining relapse rates. Highost EE = high expressed emotional. Low EE = low expressed emotion. Families tend to become over involved in recovery and become angry if it fails.

Supported by Vaughn - found 51% relapse rate for high EE environments compared to 13% in low EE. However, still some relapses. Also, Berger found schizophrenics reported more double bind statements from mothers than non schizophrenics.

Challenged by Ricks who found mothers of schizophrenics were shy and withdrawn rather than over involved and critical which challenges the theory. Also bidirectional as schizophrenia could cause family dynamics. Socially sensitive as it blames the family  (counterproductive). Ignores the 6% of schizophrenics who are homeless. 

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Treatments - biological - medication

Typical drugs = old type. They sedated patients without making them unconscious. These drugs completely blocked activity of dopamine within 48 hours. 

Atypical drugs are the new type developed in the 1990s. They contain clozapine targeted at both serotonin and dopamine. They bind to receptors but are more flexible so do not completely block them and completely blocking them led to the development of parkinsons. 

Supported by Silverman who argued that althoughthere are side effects, they do aid schizophrenics. Medication allows schizophrenics to get on with their lives spending less time in hospitals. Comer said medication is praised for being the only treatment that can work alone. Relapse rates showed a decline from 55% on typical drugs to 42% on Atypical drugs, however, many still relapsing so not effective. They are cheap and easy to access.

Challenges by Sympath who found relapse rate for people who stopped medication was 75% compared to 33% who didn't stop showing patients must rely on for a long time. Risk of addiction / side effects such as impairment, blurred vision. Many believe effects are really psychological  (placebo effect). Finally, criticised for being palliative rather than curative. 

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Treatments - biological - ECT

Electro convulsive therapy. Based on the belief that anot epileptic seizure alters chemicals in the brain. Doctors believe both schizophrenia and seizures can exist at the same time. ECT has changed drastically over time, now it is more protective of the patients well being even if they have no idea what exactly ECT does still.

The patient is given an anesthetic and muscle relaxant, electrodes are placed unilaterally on the brain, a voltage of electricity is passed through for a split second. Patients can now have up to 12 sessions. In older days, patients suffered several consequences as no anesthetic was given, shocks were higher and for longer, patients often suffered broken bones/fractures.

Supported by Fisk who found 60-80% success rate on ECT cases. However this was only evident for certain subtypes. Also, Bragg reviewed ECT cases and found all had positive outcomes. However, only used 42 cases.

Challenged by Adams who said there is no real understanding how ECT works and compared it to "banging a TV til it works". Severe side effects even with the newer version-  memory loss, motor disruption  (counterproductive). Unethical as many claim schizophrenics are not in the right mind to give informed consent. Only effective for short term release unlike CBT. Considered palliative not curative. 

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Treatments - Psychological - CBT

Aims to alter the way the patient thinks and emotional dysfunctions. Therapist builds a relationship with patients to identify underlying causes. Homework is set for patients to gradually overcome any issues eg social problems so making conversation daily. Therapy empowerthe patient. Chadwick found a man who claimed to predict the future from watching TV,  after 50 attempts, he realised he was thinking irrationally. 

Tarrier proposed a more modern version - CSE (coping strategy enhancement). Patients were asked to identify triggers and coping strategies like distraction when experiencing a delusion. He found 73% of patients improved with this by targeting one symptom at a time.

Supported by Tarrier who found alleviation of positive symptoms in a CSE group compared to a non treatment group. However,  ignores any negative symptoms. Also, Sensky found CBT effective for all symptoms for pateints who were resisting medicine. Zimmerman found CBT effective for 12 months for most patients. However, high relapse rate-not effective. CBT is highly recommended as it empowere the patients and fits individuals needs. CBT is said to be 60-80% effective but only alongside medication.

Challenged by paranoid schizophrenics who find CBT invasive and threatening. Also requires a lot of motivation which a lot of schizophrenics don't possess. 

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Treatments - Psychological - Family intervention

This therapy aims to reduce energy negative expressions of the family teaching them how to cope and communicate better. Falloon devised family management for schizophrenics returning home to ensure they do not relapse by teaching family member to be empathetic, not demanding and change expectations. This later became psychoeducation whigh led to multiple prosram message to aiexplain schizophrenics.

Supported by Jackson who found 60% relapse rate for routine treatment compared to 25% for family treatments. However, 25% still relapsed. Also, Falloon found 11% relapsed on family therapy compared to 50% on medication. 

Challenged due to ignoring the 6% of schizophrenics who are homeless and therefore couldn't attend family treatment. Also could be counterproductive as tension could increase, family may feel responsible.

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