- Created by: Amy Sinclair
- Created on: 13-05-14 19:45
- Schneider (1959) - criteria for diagnosing schizophrenia --> positive and negative symptoms.
1) Positive Symptoms
- Main diagnositc criteria
- Excesses / Distortions (e.g. delusions and hallucinations)
- Positive symptoms usually present in acute episodes.
2) Negative Symptoms
- 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
- 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
- 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
- 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.
- 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.
- 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.
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.
- 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.
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.
- 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.
- 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
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?
Drug Treatments (Anti-psychotics).
- 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.
- 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.
- 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.
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.
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
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.
- 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.
Factors Affecting Recovery
- 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.
- 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.