Schizophrenia (complete)

what are the two diagnostic manuals for psychological disorders?

how long must symptoms be presents for a diagnosis of SZ for each of them?

• DSM 5 = mostly in US

  • Diagnostic Statistical Manual edition 5

  • 6 months+

• ICD 10 = European

  • international classification of diseases edition 10

  • 1 months+

what are the exclusions in classifying SZ?

can’t be due to organic brain disease, alcohol or drug-related intoxication, or meet early depression criteria

what is an episodic illness?

periods of symptoms and period when there are less

• sz = periods of psychotic disturbances with periods of normal functioning

what is the difference between positive and negative symptoms?

• positive is an addition to normal behaviour

• negative is the absence of normal behaviour

what are the main positive and negative symptoms of SZ?

positive

• auditory and visual hallucinations

• delusions or control, paranoia and false beliefs.

• though insertion (thinking thought have been placed in mind)

negative

• speech poverty (reduction in quality and amount of speech)

• avolition (lack of interest and motivation)

• social withdrawal - due to paranoia etc

What are hallucinations?

unusual sensory experiences

some related to the environment, others have nothing to do with what senses are picking up from the environment (eg. hearing voices)

auditory or visual

What are delusions?

false beliefs

• paranoia and irrational beliefs

• delusions of grandeur - thinking they are superior

• delusions of the body, part of them is under control

• some delusions can lead to aggression (but generally are victims of violence)

What is Avolition?

• apathy, finding it difficult to begin/keep up with a goal

• sharply reduced motivation for everyday activities

• Anderson’s 3 signs of Avolition - poor hygiene, lack of persistence in work/education, lack of energy

What is speech poverty?

sufferers experience changes in speech pattern

• ICD-10 views this as a negative symptom

• DSM places emphasis on speech disorganisation (classified as a positive symptom)

What characteristics of SZ are not needed for a diagnosis?

• weight gain

• multiple personalities

• insomnia

What are the key features of the biological approach to explaining SZ?

believes that SZ is due to biological factors such as…

• genetics

• neural correlates (dopamine hypothesis)

What % heritable is schizophrenia?

50% heritable

What is the basis of the genetic explanation?

• SZ is inherited through generations, by transmission of genes

• inheritance patterns are complex and involve a combination if genes

• 100s genes involved (polygenic)

What two candidate genes are involved in schizophrenia?

• PCM1 = pericentriolar material 1 (codes for protein involved in cell division

• DRD3 = dopamine receptor gene

What are the problems with twin studies?

1. concordance rates are never 100% - this suggests that genetics are not the only cause of SZ. other factors are involved such as hostile family relationships or drug use.

2. sample size - MZ twins are rare and only 1% would be expected to have SZ so must be cautious in drawing conclusions

3. twins share an environment so difficult to determine what is genetics and what is not (concordance rates may be displaying the effects of their shared environment)

What is the supporting evidence for the genetic explanation for SZ?

gottesman 1991 - concordance rates of SZ

MZ= 48%

DZ = 17%

gives strong evidence that genetics are an important factor in determining SZ

Tienari 1991 - finnish adoption study

• group 1 = 155 adopted whose bio mother had SZ

• group 2 = matched group of adopted children with no family history of SZ

findings →

• group 1 = 10% developed SZ

• group 2 = 1% developed SZ

gives strong evidence that genetics are important

What are neural correlates?

measurements of structures/neurochemistry of the brain that correlated to symptoms of SZ

What is the dopamine hypothesis?

• the involvement of dopamine in SZ

• dopamine is a neurotransmitter in the limbic system associated with motivation and attention

• imbalance of dopamine can be inherited or due to environmental factors

What are Hyperdopaminergia and Hypodopaminergia?

hyper = excess activity of dopamine in the subcortical areas of the brain

hypo = low activity of dopamine in the prefrontal cortex

what are the causes of hyperdopaminergia?

• elevated pre-synaptic dopamine (more being synthesised and stored in its vesicles)

• excess dopamine released into the synapse

• increased density of receptors on post-synaptic neurons

there is evidence for all 3

What are the practical applications for the dopamine hypothesis/biological approach?

antipsychotic drugs

block activity of dopamine in the brain, and reduce the symptoms of SZ (eg. hallucinations)

suggests that overactivity if dopamine is important in SZ

early diagnosis

if we see what can predispose people (eg. genes) then we can treat them early

what are 3 negative evaluations of the biological explanations?

research is all correlational

• which means there is a relationship but does not help to define cause and effect

ignores environmental risk factors for SZ

• include; markers of social adversity (abuse, migration, lack of friends), pregnancy complications and prenatal stress. - could be argues it is reductionist

issues and debates

• deterministic = suggests that a person is destined and that there is no choice

what are the biological treatments for SZ?

• typical antipsychotics, introduced 1952

• atypical antipsychotics, introduced 1970s

What are the functions of typical antipsychotics?

• dopamine antagonists (work against the actions of dopamine

• block actions of D2 dopamine receptors on the post-synaptic neuron by binding to them

• reduces positive symptoms (hallucinations in a few days and delusions in a few weeks)

• symptoms controlled in 2 weeks

• sedative effect

Examples of antipsychotics

How can they be taken?

clozapine, risperidone

• tablets syrup or injections

• daily up to 1000mg a day (doses start small and increase)

• most on 400-800mg

what is the function of a-typical antipsychotics?

• block dopamine receptors and also act on other neurotransmitters eg. serotonin

• it is thought they temporarily bind to D2 receptors and rapidly dissociate allowing for normal dopamine action

• address positive and negative symptoms

what are the side effects of typical antipsychotics?

• dry mouth/constipation

• 20-25% have motor issues (eg. tardive dyskinesia, involuntary tics)

results in 50% discontinuing the medication in the 1st year

What are the side effects of atypical antipsychotics?

agranulocytosis

• autoimmune disorder causing severely low levels of white blood cells

• puts person at high risk of infection

• need blood monitoring monthly which may create more issues with paranoia

Why are antipsychotics an effective method of treatment for SZ?

• cheap compared to other treatments

• lead to enhanced quality of life - living independently outside of institutionalised care

  • enables return to work

supporting evidence for the effectiveness of typical antipsychotics

Thornley 2003

• reviewed 50 controlled trials including over 1500 ppts

• chlorpromazine reduces relapse over six months to two years and promotes overall improvement in symptoms and functioning compared to a placebo.

however…

• not effective for everyone (large portion of people are drug-resistant

• negative symptoms not treated

• most studies focused on the short-term rather than long-term benefits.

supporting evidence for the effectiveness of atypical antipsychotics.

meltzer 2012

• concluded clozapine more effective at treating both types of symptoms than typical APs

• patients showed improvement in symptoms even those that were drug resistant to typical APS (30-50%).

• evidence to show atypical APs are more effective

what are the issues and debates for biological the treatments?

based on bio explanations which may be seen as reductionist

• can be too simplistic and miss other factors that are involved in the development of SZ (eg dysfunctional family environment) leading to treatment of symptoms rather than causes

Why may antipsychotics be ineffective?

treats the symptoms and not the causes

• drugs only effective at reducing symptoms and do not address the source of the problem (not a complete treatment)

• alternative psychological treatments may be more suitable as well as drugs (interact)

  • CBT

  • Family therapies

What are the two main psychological explanations for SZ?

• family dysfunction

• cognitive deficits

what is family dysfunction?

What are two characteristics of it?

• SZ has been linked to living in a dysfunctional family environment

  • not operating properly

  • 4 Cs (conflict, communication problems, Criticism and control)

Could be characterized by…

• high expressed emotion (EE)

• double bind situations

What is high EE as an explanation for SZ?

• dysfunctional family characteristic where there are high levels of negative emotion

  • verbal criticism

  • hostility

  • emotional over control

• put person under stress triggering SZ

What 2 symptoms of SZ may high EE lead to?

• social withdrawal - avoid hostility or criticism

• thought insertion - from over-involvement and control, or verbal criticism

What are double bind situations as an explanation for SZ?

Bateson 1956 - investigated family communication styles

• risk factor for the development of SZ was double bind situations

• ‘no win’ situations

• child receives conflicting messages about their relationship

• child does not know how to respond as whatever they do may feel wrong

What 2 symptoms of SZ may double bind situations lead to?

• paranoid delusions - stem from the belief that the world is dangerous and that people are trying to hurt them

• disorganised thinking - results from seeing the world as confusing and hard to make sense of

what is the supporting evidence for Double bind situations?

Berger (1965)

found that people with SZ reported a higher recall of double bind statements by their mothers than the control group

however…

• retrospective

• SZ may affect the accuracy of recall

• reliant on honesty and non-bias relationships with mothers

What is the contradictory evidence for double-bind situations?

hall & Levin (1980)

analysed data from previous case studies and found no difference between families with and without SZ family members in the number of double binds observed

however

• families may change behaviour under overt observation

• case studies are unique and it is hard to generalised to the wider population

What is the supporting evidence for high expressed emotion?

Marcus 1987

prospective longitudinal study of ‘high risk’ children who had a parent with SZ

• found that the children who went on to develop SZ were more likely to come from families with negative relationships (high EE)

• out of the high-risk group nobody that had received ‘good parenting developed SZ

• suggests high EE may trigger the development of SZ (not necessarily a cause)

What is the basis of the cognitive explanations for SZ?

• focus on impaired information processing

• frith et al 1992 identified the two types of dysfunctional thought processes that can underlie the symptoms of SZ

1. deficit in metarepresentation

2. deficit in central control

what is metarepresentation?

the ability to reflect on, and have insight into, our own intentions and the actions of others

identifying if thoughts have originated from within ourselves or the environment

what 3 symptoms of SZ can be explained by deficiency in metarepresentation?

• hallucinations - believing sound or thoughts from the internal self are external

• delusions of control - believing that external forces are in control of internal forces

• thought insertion - believing external thoughts from others are internal.

what test can be used to test processing deficits?

the stroop test

what is central control?

• ability to suppress automatic responses while we perform deliberate actions instead

• disorganised speech can result from the inability to suppress automatic thoughts

what is the supporting evidence for cognitive explanations for SZ?

Shen et al 2013

• compared 86 people with SZ and 86 controls

• 13 different computerised tests (eg. pressing the response key when an image appears or the Stroop test)

• found people with SZ performed significantly worse on activities that required sustained and focused attention.

what is the contradictory evidence for cognitive explanations of SZ?

McKenna 1994

found that people with SZ are not any easier to distract than others when engaging in a cognitive task - challenges the idea of cognitive deficiencies

What are the practical applications of psychological explanations?

• development of family interventions aimed at reducing EE and avoiding double binds

• use of CBT to challenge symptoms such as paranoia and delusions to give the patient more control over their reality

what are the issues and debates of the psychological explanations for SZ?

• on the nurture side of the nature-nurture debate

• underestimates nature, which is a problem as there is strong genetic evidence behind SZ

• difficult to define how much of a role the family environment has - not a complete explanation

What are the two main psychological therapies?

• CBT

• family therapy

what is CBT?

cognitive explanations say SZ symptoms result from dysfunctional thought processes, leading to faulty interpretation of events

CBT aims to correct these thought patterns

what is the procedure of CBT?

1. techniques to identify/challenge irrational beliefs by reality testing to reduce stress

2. coping strategy enhancement (CSE) patients develop cognitive strategies to cope with their symptoms eg. use of distraction, concentrating on a specific task

3. increasing social activity and relaxation techniques

what are 3 strengths of CBT?

• allows patient to take responsibility for their own treatment

• long-term treatment providing strategies to help in the future

• ways of challenging dysfunctional thinking so that the patient can engage in other areas of their life more

What are 3 weaknesses of CBT?

• willingness to engage (based negative symptoms) may make the therapy less effective

• hallucinations and delusions make hard to engage

• practical issues length of therapy can lead to drop out

What is the supporting evidence for CBT?

pilling et al 2002

• meta-analysis of CBT

• 392 ppts

• concluded CBT was effective in improving mental state during treatment and after at a follow-up

What is family therapy?

• assumes that SZ is due to family experiences of conflict, communication problems etc (high EE, double binds)

• aims to develop a cooperative relationship in a family

• can help to learn constructive ways of communicating and expressing negative emotions

What is the procedure of family therapy?

• information about the cause, course and symptoms of SZ provided

• all family members share their experience

• develop coping skills to help everyone manage having SZ in the family

• 3-12 months approx

• everyone taught to recognise the signs of relapse and how to respond quickly

what are 3 strengths of family therapy?

• no side effects

• benefits the whole family (damage control)

• treats causal factors (high EE and DBs)

What are 4 weaknesses of family therapy?

• need to have a family group

• time-consuming

• the whole family need to be motivated to attend

• not appropriate for severe cases of SZ (where symptoms are severe and sharing experiences was worsen the situation)

What is the supporting evidence for family therapy?

Pharoah et al 2010

conducted a meta-analysis of 53 trials from Europe, Asia and north America comparing family therapy (and drugs) and standard care (drugs alone)

concluded that family therapy

• decreases the frequency of relapse,

• reduces the chance of hospital admission

• encourages compliance with medication

• significantly reduces EE in the family

more likely to treat the underlying cause than bio treatments

what is a management method of SZ?

token economies

what are token economies?

• reward systems used to manage behaviour with SZ

• those who have been institutionalised for long periods may have developed bad habits (poor hygiene, not getting dressed for the day)

• staff positively reinforce patients by giving them a token for desirable behaviour

• tokens can then be swapped for more tangible rewards such as going on a walk outside or getting a sweet

What are 3 main issues with token economies?

• not a treatment as for desired behaviour patients are dependent on receiving a reward (no benefit to positive symptoms)

• manipulative + patronising - underestimating cognitive factors

• discrimination = privileges more available to those less unwell

What is the supporting evidence for token economies?

mcmonagle and sultana 2009

• meta-analysis of token economy systems involving 110 people with SZ

• slight evidence for improved mental state especially for negative symptoms

however

• only 3 studies of random allocation meaning there is bias results as least unwell patients would have taken part

what is a diagnostic system?

• set of possible types of abnormality (classification)

• and the rules for recognising them (diagnosis)

  • rules set out in manuals such as DSM and ICD

what are 4 advantages of classification and diagnosis?

1. communication = diagnosis improves communication between health professionals

2. treatment = reliable diagnosis can lead to appropriate treatment

3. prognosis = diagnosis can provide valuable information about the course of a disorder.

4. cause = Knowing diagnosis can aid research into the potential causes of the disorder.

what are 3 issues with classification and diagnosis?

1. misdiagnosis = may be given the wrong treatment

2. labelling = can be helpful in providing correct treatment but could lead to self-fulfilling prophecy (a belief that can influence behaviour)

3. historical-cultural context = disorders in the manuals may reflect the current attitudes (social/political) eg. Homosexuality was included in earlier manuals under sexual disorders, must understand the individuals cultural frame/context

What is reliability in classification and diagnosis?

• level of agreement/consistency of diagnosis between psychiatrists over time and culture (inter-rater)

• consistency of diagnosis over time given no change in symptoms (test-retest)

what is the contradictory evidence for reliability in classification and diagnosis of SZ?

copeland et al (1971)

• gave same patient descriptions to 134 US and 194 UK psychiatrists

• 69% of US diagnosed SZ but only 2% of UK

what is the supporting evidence for reliability in classification and diagnosis of SZ?

Soderberg et al (2005) reported a correlation of 0.81 among psychiatrists using the DSM system to diagnose schizophrenia.

shows that more recently there has been improvements in the manuals making them more reliable

How can the issues of reliability in the classification and diagnosis of SZ be dealt with?

improve the manuals

• there were many differences between the early versions of the DSM and ICD

• those in current use are more similar but still contain some differences eg. the length of symptom presentation for diagnosis

what is validity in the classification and diagnosis of SZ?

extent to which SZ is unique with it’s characteristics symptoms and signs

• to be valid, patients should have different symptoms than those with different disorders.

What are 5 issues affecting validity in the classification and diagnosis of SZ?

• co-morbidity

• gender bias

• culture bias

• symptom overlap

• range of symptoms

How does co-morbidity effect validity (incl supporting evidence)?

• two or more conditions occurring together in the same person at the same time

• Buckley et al 2009

  • found that 50% of patients with SZ have depression or substance abuse, 23% OCD and 19% PTSD

• if conditions occur together a lot, this questions the validity of disorders as they may be the same condition

how does gender bias effect validity (incl supporting evidence)?

longnecker et al (2010)

• since 1980s men have been diagnosed with SZ more

• men may be more genetically vulnerable

• female patients function better (more likely to work, maintain good relationships etc) than males so diagnosis may be missed

How does culture bias effect validity (incl supporting evidence)?

Keith et al (1991)

• 2.1% African Americans diagnosed compared to 1% of white population

• many people from African cultures are praised for hearing voices and ‘being able to communicate with ancestral spirits’

• means they are more likely to report these experiences which are then misinterpreted as symptoms

How does symptom overlap affect validity?

• considerable overlap with SZ and other disorders. (eg bipolar)

• the person may show symptoms of typical SZ (eg delusions) but could have a different disorder that has the same symptom

• means it is hard to define boundaries between SZ and other disorders

  • could lead to incorrect diagnosis

how does the range of symptoms affect validity?

• there are a range of symptoms that could be present for the diagnosis of SZ (pos/neg)

• 2 individuals could display very different behaviour but have the same diagnosis of SZ

What is the interactionist approach?

considers how biological, psychological and social factors interact to influence the development of SZ.

what is the diathesis-stress model?

model states that individuals have varying internal vulnerabilities for SZ (diathesis) that combine with external environmental stressors to account for the development of the disorder.

• internal vulnerabilities originally thought to be genetic (leading to biochem abnormalities) but now includes childhood trauma affecting brain development

  • inability to process information normally

• external stress trigger could be any negative psychological experience

what is the supporting evidence for the diathesis-stress model?

Gottesman 1991

• concordance rates of 48% for MZ, suggest genetic impact but also other factors involvement (environmental triggers like dysfunctional families)

Marcus 1987

• prospective longitudinal study of ‘high risk’ children who had a parent with SZ

• children developing SZ are more likely to come from high EE families

• none who received ‘good’ parenting developed SZ

• suggests that genetic vulnerability for developing SZ only triggered in appropriate environmental conditions

What is the support for other vulnerabilities to SZ?

early adverse events such as child abuse could be contributors to the diathesis.

• read et al (2001) suggests traumatic childhood events can cause changes in brain development, causing vulnerability

  • suggests that vulnerabilities can be neurodevelopmental, not just genetic

how has cannabis been linked to SZ?

evidence shows that cannabis use, mainly at a young age, creates a higher risk of developing SZ

• Semple et al 2005 - The major psychoactive component in cannabis, THC, creates transient negative effects on cognitive functioning and psychotic symptoms

• not all users develop SZ

• suggests it is not a cause but must interact with another factor

cannabis may be a stressor to a genetic vulnerability

What are the general evaluations of the interactionist approach?

• not clear how different risks interact to contribute to the development of SZ

• causes differ between people meaning there is no universal criteria for the development of SZ

How can the interactionist approach be used to treat SZ?

• combined treatments are most effective

• patients given antipsychotics to reduce the symptoms

• engage in psychological treatments such as CTB and Family therapy for coping

  • may increase compliance with drug treatments

    • drug treatment throughout

What is the supporting evidence for interactionist treatments of SZ?

guo et al 2010

found that patients receiving drug and therapeutic treatments had:

• improved understanding of condition

• improved quality of life and social function

• more likely to continue treatment

• less likely to relapse than when doing drug therapies alone

What are the issue and debates with the interactionist approach treatment for SZ?

• holistic for explaining and treating SZ

• the diathesis-stress model shows we can’t explain SZ by simplifying it down into small elements

• in this case most effective treatment is holistic