Schizophrenia

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  • Created by: Laura
  • Created on: 10-06-13 18:17

Introduction

4 types: Paranoid, Disorganised, Catatonic, Simple, Undifferentiated (where they cannot be catagorised as any other type)

Positive symptoms

Delusions - e.g. paranoia or exaggerated beliefs of own power/importance etc.                          Hallucinations - distortions of sensory perceptions                                                                     Experiences of control - believing they are under control of other forces (e.g. God, aliens etc)        Disordered thoughts - thoughts are muddled and make no sense                                                Disordered speech - or 'word salad', repeating words or rhyming words

Negative Symptoms

Flat effect - lack of expressed emotion in face/body language                                                  speech poverty - (alogia) - lack of speech or vagua and repetitive speech                                      social withdrawal - distancing themselves from others and withdrawing into their own world            inappropriate effect - involves actions such as giggle at a funeral

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Issues surrounding diagnosis + classification - RE

NO scientific test for schiz exists, Diagnostic systems must produce consistency over time 

HOWEVER - diagnostic system is always changing showing lack of consistency + indicating that probs with system still exist

Also between clinicians. If clinicians disagree over a diagnosis whilst using the same system, it suggests that this system has a low reliability. HOWEVER- research has shown consistency doesn't exist (e.g. Rosenhaan - being sane in insane places)

EVAL - psychiatrists dont expect 'normal' people to try and gain admission so validity of research is low due to DC and low mundane realism.  - This does show unreliability of diagnosis

Existence of diff types of schiz raises reliability issues, as those diagnosed with different types of schiz have completely different symptoms so why are they seen as having the same general diagnosis of schiz?

category of undifferentiated is too vague for patients who may have a wide range of symptoms but are hard to classify into other type, patients with undifferentiated may have no symptoms in common with others.

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Issues surrounding diagnosis + classification - VA

For a diagnosis to be valid the diagnosis system used has to measure/assess what is claims to, therefore do patients diagnosed with schiz actually have it? If a diagnostic system is seen to be valid it must also have a high reliability.

The fact that there is inconsistency between clinicians and over time suggests diagnostic system is not measuring what it claims to and has a low reliability. System also need to take place in psychotic stage BUT communication is likely to be poor during this time.

  PREDICTIVE VALIDITY - prognosis etc should be the same for all people with schiz, however   CONTENT VALIDITY - does system cover wide range of symptoms                                   CRITERION VALIDITY - those with schiz should differ in predictable ways from those who do not have schiz- HOWEVER symptom overlaps (disosiative identity disorder) have more schiz symptoms than schiz                                                                                           CONSTRUCT VALIDITY -  casual hypothesis - if high dopamine = schiz, so schiz patient with high dopamine supports hypothesis.

BUT contradictory findings suggest either hypothesis is wrong or diagnosis is wrong. Contradictory findings are common

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Genetic explanations

Schiz does seem to run in families. genetic argument suggests this is due to the condition being carried and passed on through genes. Therefore - the closer the genetic link to someone with schiz the greater the likelihood of developing it as a result of shared genetic inheritance

This is assessed by looking at concordance rates between MZ twins (sharing 100%), DZ and first degree relatives (sharing 50%), second degree (sharing 25%) and thsoe with no blood relationship at all (e.g. adopted). 

Family -  studies have found concordance rates to be higher  amongst first degree relatives. Gottesman - Reviewed concordance rates from fam studies and found children with both parents suffering from schiz had 46% concordance rate compared to a rate of 16% if only one parent had it.                                                                                                                                     Twin - The assumption is that concordance rates should be higher amongst MZ than DZ. Gottesman - in a review of 40 studies found concordance rate of 48% amongst MZ and only 4% DZ which still supports genetic argument.                                                                              Adoption - Concordance rates should be higher amongst biological than adoptive relatives. Tienari - in finland compared 155 adopted children whos parents had schiz with a control group of adopted children who did not have schiz parent. Rates were 10% for those with schiz mum compared to 1% for control group

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Dopamine hypothesis

Suggests that high levels of dopamine may cause schizophrenia. Anti psychotic drugs inhibit effects of dopamine can reduce schiz symptoms. Also, the drug l dopa (which treats parkinsons) produces symptoms similar to that of positive schiz in non schiz patients as do other drugs which increase dopamine activity (e.g. amphetamines, LSD)

Alternatively, dopamine levels may in fact be normal but they may be an excess number of dopamine receptors in the brain creating an increased uptake of dopamine. OWEN found in post mortem examinations that schiz patients have a high density of receptors.

EVALUATION - There is no support for the claim that schiz patients  have excess of dopamine. Though antipsychotics reduce symptoms, they only reduce the positive ones. Even then not all schiz's  with positive symptoms benefit in the same way

Similarly amphetamines can worsen positive symptoms and lessen negative ones.

One of the most effective ways to treat schiz is with clozapine which has a greater effect on serotonin dopamine suggesting that....

Post mortem findings are only correlational

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Psychodynamic

Freud argued that all children go through the psychosexual stages of development, first stage being the oral stage. He argued that if a child has problems at any stage they will become fixated at that stage. Later in life stressful situations could cause an individual to regress back to that stage and they will display behaviour from the stage at which they became fixated.

According to Freud psych has three parts. The ID, ego and superego. The ego develops in the first 2 years and works on the reality principle. His explanation of schizophrenia is that;

Most schizophrenics had a childhood with cold, overbearing parents leading to a fixation at an early oral stage. Schiz develops when adult regresses to oral stage before ego is developed, thereby losing touch with reality + resulting in symptoms such as delusions.

Regression to a pre ego stage results in a person striving to regain sense of reality and control - auditory hallucinations may be compensation for this.

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Cognitive Explanations

claims that physiological brain abnormalities lead to cognitive malfunction, one such malfunction relates to ATTENTION. Normal brains can focus attention by filtering out unnecessary info, but, the brain of a schizophrenic is unable to filter properly therefore leading to an overload of information.  Their sensory expriences are therefore different (e.g. auditory hallucinations)

However these experiences are not confirmed by others, leading to mistrust and rejection of those closest to them and development of hallucinations. Also the theory cannot explain why they can't filter out this information.

Double bind theory - family theory - mixed messages from mother e.g. body language saying one thing whilst verbally saying something different --> link with negative symptoms

FRITH + HELMSLEY 

Eval - sees root causes as physiological but fails to elaborate on this, is more descriptive than explanatory. Evidence is weak - findings suggest that those with schiz perform poorly on  cog tasks. MEYER LINDENBERG. Cog skills tests have also found these deficits exist in ppl with other conditions e.g. bipolar suggesting it can only be a partial explanation.

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Researching effectiveness of treatments/therapies

Treatments should bring about an improvement in the individual by reducing symptoms. Research can establish which treatment is best, however, problems with research exist thereby reducing our ability to draw firm conclusions. To evaluate studiesmany things need to be taken into consideration;

Operational definition: there must be an agreed definition of the disorder which can be measured                                                                                                                  Allocation to treatment groups: random to avoid bias                                                              Effect of existing treatment: pps may have already and some treatment which may confound results of research into new treatment e.g. drugs which reduce concentration making CBT less effective.                                                                                                                                  Placebo effect: a therapy may show improvements simply due to attention and expectation of success so a placebo group should be included in research.                                                        Measuring improvement: what is the criteria for deciding if a treatment is effective or not? is it clear?

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Therapies - Conventional Antipsychotics

These block some dopamine receptors and so reduce effects of dopamine and positive schiz symptoms. Research by Sampath. 

Effectiveness - Conventional antipsychotics often most effective but not in all cases. More effective with positive symptoms. Side effects =sedation, reduced concentration, parkinsons symptoms, tardive dyskinesia. 

Appropriatness - Appropriate in treating biochemical cause. Can be inappropriate as patient compliance is required +because of the side effects etc  patients might stop taking medication.

ATYPICAL;

These block dopamine activity and effect serotonin activity. They reduce symptoms, even those not responding to conventional + can also reduce negative symptoms. Research - AWAD        Eval - more effective in reducing symptoms including some negative symptoms but this improvement may be small. Less side effects but in minority cases they can be serious.

Appropriateness - same as conventional, Effectiveness of antipsychotics support biochemical research

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ECT

Small electric current is passed through the brain (whilst patient is under mild anaesthetic) to induce a seizure which is thought to effect brain deficits whoch could be the cause of hallucinations, delusions etc. 

Research - studies that have compared a real ECT condition with a placebo found the real ECT to have a bigger improvement on brain deficits.

Effectiveness - ECT is effective but more so when combined with other treatments e.g. drugs. When used alone not as effective as drugs. Beneficial effects are mostly short term. More effective with positive rather than negative symptoms.

Appropriatness - Appropriae as a bio treatment effecting brain function. May be inappropriate for its side effects such as memory loss. not clear whether neurological damage may be caused. 

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CBT

Aims to challenge irrational thoughts and beliefs which can contribute to schiz (e.g. paranoia). Many schiz already use coping strategies to deal with hallucinations, delusions etc. CBT is used to enhance and/or improve existing strategies. Also attempts to identify what triggers symptoms (e.g. stress) and to find ways to avoid these triggers.

Research - Gould Et al - in a meta analysis found significant reductions in positive symptoms following CBT.

Effectiveness -  effective in treating some positive symptoms and can improve social functioning . but most patients also recieve drugs so assessing effectiveness of CBT in isolation is difficult

Appropriateness - Appropraite in treating cognitive symptoms (e.g. hallucinations, delusions). Enhancing existing coping strategies is very appropriate. However, long, time consuming, expensive and need commitment so patients drop out. Biological factors acknowledged by cognitive approach are not addressed. Effectiveness supports cognitive explanation of schiz but in limited way as its less effective on its own.

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Psychodynamic therapy

Purpose is to identify past conflicts which leads to schiz. These are in the unconscious so a relationship of trust must be built with the therapist to bring unconscious conflicts into consciousness where they can be dealt with. As conflicts are seen as the cause of symptoms once they are dealt with the symptoms should reduce.

Gottdiener - meta analysis of 37 studies founds 66% of those receiving psychotherapy improved compared to 35% not recieving therapy, even when not accompanied by drugs.

Effectiveness - effective for some but difficult to assess whether improvements are a result of therapy or just increased attention. Gottdiener found CBT just as effective.

Appropriateness - not appropriate for all as trust relationship with therapist may not be possible for patient. Long, expensive, time consuming so need commitment from patients who may drop out. Some reports that therapy has been detrimental . Finally, gaining insight into childhood conflicts may not be possible for all.

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