Schizophrenia Revision (Diagnosis, Aetiology, Treatments)

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Schizophrenia Description

  • Schneider (1959) - criteria for diagnosing schizophrenia --> positive and negative symptoms.

1) Positive Symptoms

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    • Main diagnositc criteria
    • Excesses / Distortions (e.g. delusions and hallucinations)
    • Positive symptoms usually present in acute episodes.

2) Negative Symptoms

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    • Behavioural deficits --> tend to last beyond acute episodes into chronic episode.
    • Important prognostically - many negative symptoms = poor quality of life. 
    • Apathy, Alogia, Anhedonia, Asociality and Flat Affect 

3) Disorganised Symptoms

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    • Speech and behaviour - problems speaking so listener can understand/trouble making behaviour conform to everyday standards. 
  • Catatonia = repeating gestures over and over/adopt unusual posture and maintain for long periods.
  • Inappropriate Affect = emotional response out of context, e.g. laugh at hearing about a death. 
  • 3 Stages - 1) Prodromal, 2) Active, 3) Residual
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Epidemiology

  • Perala et al (2007) - 3.2% of population have schizophrenia
  • Onset usually mid 20s/early 30s
  • Onset rare after 45 years of age
  • More common in men than women.
  • Often begins after a prolonged period of stress
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Genetic Aetiology

Family Studies

  • Kendler et al (1996) - relatives of schizophrenics at risk, risk increases as genetic similarity increases. 
  • Malaspina (2000)    - Family history of Sz = more negative symptoms = negative symptoms                                    may have stronger genetic component?
  • Kender et al (1995) -  Relatives also at risk of related disorders e.g. schizotypal personality disorder.

Twin Studies

  • Gottesman (1987) - higher concordance for MZ twins than DZ. 
  • Gottesman (1981) - risk increases when Sz twin is more severely ill. 
  • Canon et al (1998)- concordance not 100% so genetics can not be the sole influence. 

Adoption Studies

  • Heston (1966) - control group = 0% had Sz; Sz mother group  16.6% had Sz. 
  • BUT! - Birth mother and child shared environment for a limited period of time. 
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Neurotransmitter Aetiology (Dopamine Theory)

  • Based on the efficacy of drugs that reduce dopamine for treating schizophrenia.
  • Suggests Sz may be caused by overactivity or elevated levels of dopamine. 
  • Comer et al - stress = increased dopamine firing = delusions / hallucinations. 

Amphetamine Psychosis

  • Amphetamines can produce a state similar to paranoid schizophrenia. 
  • They cause increased release of dopamine and NA
  • Further evidence for increased dopamine and schizophrenia link . 
  • Wong et al (1986) - PET scan - higher dopamine in Sz patients than controls. 
  • Glutamate, GABA and Serotonin may mediate dopamine <---> schizophrenia link. 
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Brain Structure and Function Aetiology

1) Enlarged Ventricles

  • McNeil (2000) - Schizophrenia patients often found to have enlarged ventricles.
  • This is not exclusive to schizophrenia
  • Link not fully understood but seem to be related in some way.

2) Prefrontal Cortex (PFC) Dysfunction

  • Prefrontal cortex responsible for a number of the things disrupted by schizophrenia. 
  • Buchanan et al (1998) - reduced grey matter in PFC of schizophrenics. 
  • Barch et al (2003/2003) - poor performance on tasks which utilise PFC.
  • Barch et al (2001) reduced activation in PFC of schizophrenics.
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Diathesis-Stress Model

  • Attempts to explain behaviour as a predispositional vulnerability together with stress from life experiences.
  • Diathesis = disposition or vulnerability. 
  • Outlines the importance of both nature AND nurture in the development of psychopathology.

1) Diathesis (Vulnerability).

  • Can be biological = genes/brain structure. 
  • Can be social = chronic stress, poor social skills
  • Can be psychological = unconscious conflicts, poor life skills. 

2) Stress

  • Stressors = life events which can disrupt the equilibrium of a person's life and can be a specific event e.g. divorce/loss or could be from chronic factors such as long-term illness. 
  • Can be biological = onset of disease / exposure to toxins. 
  • Can be social = traumatic event
  • Can be psychological = perceived loss of control. 
  • DIATHESIS + STRESS = SCHIZOPHRENIA DISORDER
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Past Treatments of Schizophrenia

  • Electric Shock Therapy (E.S.T.) 
  • Literally "Shaking" the madness out of a person.
  •  
  • Cold baths - have a calming effect. 
  • Trepanation - holes in skull to relieve pressure. 
  • Blood letting - to let out badness in blood. 
  • In the past people were confined to psychiatric unit and could not leave. 
  • People did not have the choice/right to refuse treatment.
  • Could past treatments and treatment of individuals be classed as inhumane?
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Drug Treatments (Anti-psychotics).

1st Generation

  • E.g. Thorazine, Haldol
  • Able to reduce positive symptoms but had little effect on negative symptoms - partially effective
  • Only had effects on dopamine (which is responsible for positive symptoms)
  • Lieberman (2005) - Many dropped out of trials due to unwanted side effects.

2nd Generation

  • Wahlbeck et al (1999) - Clozapine - improved positive and disorganised symptoms.
  • Found to be effective at reducing relapse (Conley et al, 1999)
  • BUT! - also found to reduce white blood cell count/immune function among other effects.

3rd Generation

  • E.g. Zyprexa, Risperdal
  • Dolder et al (2002) - As effective as 1st gen but less side effects and lower drop out rates.

MATRICS Project - developed to compare medications for treating certain individuals.

Battery of tests completed to assess Sz stageand most suitable medication chosen based on results.

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Evaluation of Drug Treatments

  • Despite unwanted side effects are an indispensible part of treatment. 
  • Limited success of previous drugs has prompted development of new ones & promising new drugs are continually being trialled and evaluated.
  • Medication is not a cure but can make symptoms a lot more manageable. 
  • Hogarty et al (1974) - Use must be continued to avoid relapse.
  • Most individuals are not fully compliant so the level of relapse is high. 
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Cognitive Therapy / CBT

  • Influenced by Beck and Ellis. 
  • Person's beliefs / appraisals of a situation are faulty --> misattribution. 
  • Must change faulty assumptions and thinking. 
  • Challenge delusional thinking --> challenge evidence for beliefs and provide more realistic explanation. 
  • A range of coping strategies have been developed:
  • e.g. thought blocking (drowning out voices), relaxation techniques, testing faulty cognitions (delusions)
  • Latest approach is coping strategy enhancement.
  • Uses a range of cognitive-behavioural strategies at same time. 
  • Turkington et al (2002) - Useful at minimising some symptoms but not all 
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Community Care Treatment

  • Management / treatment of patients within a community setting. 
  • Developed since closure of long-term institutes. 
  • Assumption that if acute symptoms are treated vigorously then person can return to care of GP/community. 
  • Reduces the need for long-term institutes & people can return and live with family. 
  • Support is tailored to each individual - organised by nurse or small team. 
  • Mueser et al (1998) - If needed, other services can be brought in to impove effectiveness. 

Efficacy

  • Stein & Test (1980) - 89% relapse for inpatients compared to 18% for community care. 
  • BUT! - gains steadily lost at end of program.
  • Excellent idea and principle but not enough support services available. 
  • Highlights the importance of treatment tailored to each individual and stage of illness. 
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Factors Affecting Recovery

1) Non-Compliance

  • Julien (2008) - Conventional antipsychotics (1st Gen) = 65% compliance.
  • Julien (2008) - Atypical (2nd/3rd Gen) = 85% compliance.
  • Comer (2010) - 2nd/3rd Gen able to treat some negative symptoms but also have many negative effects.
  • Low compliance = poor prognosis and increased chance of relapse.
  • Moritz et al (2009) Full compliance is linked to fewer psychotic symptoms & side effects.

2) Social Factors

  • Disorder strongly affected by social context.
  • Acute symptoms can be influenced by the family situation.
  • Increased chance of relapse if social situation unfavourable. 

3) Beliefs about Medication

  • Families worried about side-effects/addiction --> no addictive behaviour seen.
  • "Chemical straitjacket" - notion untrue - do not take away free will, simply help individual deal with world more rationally.
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Prognosis

  • Schizophrenia can be treated
  • There is often a high chance of relapse (less if compliant with medication)
  • Social situation and stress strongly influence level of relapse. 
  • 1/3 recover normally.
  • 1/3 wax and wane.
  • 1/3 need permanent drug treatment.
  • May not be cured but at least symptoms can be reduced / controlled.
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