Unraveling Schizophrenia: Understanding and Explaining

Unraveling Schizophrenia: Understanding, Explaining, and Treating
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Slide 1: Tekstslide
PsychologyFurther Education (Key Stage 5)

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Unraveling Schizophrenia: Understanding, Explaining, and Treating

Slide 1 - Tekstslide

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Learning Objective
At the end of the lesson, you will be able to understand the diagnostic criteria, explanations, and treatment methods for Schizophrenia.

Be able to name and explain key studies, as well as evaluating their strengths and weaknesses

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What do you already know about Schizophrenia?

Slide 3 - Woordweb

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Diagnostic Criteria for Schizophrenia
  • According ot the ICD-11, schizophrenia should be diagnosed if a person shows at least one of the core symptoms for at least one month. Two symptoms may be necessary in less clear-cut cases. Other causes of the symptoms must be eliminated before a diagnosis is made - for example, substance misuse, side effects of medication or an underlying physical condition, such as a brain tumour.

  • The ICD-11 categorises symptoms into six dimensional descriptors (Reed et al., 2019), each rated on a four-point scale (not present, mild, moderate and severe). The dimensions include positive and negative symptoms, as well as symptoms relating to mood, cognition and behaviour.

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Positive Symptoms
  • Hallucinations: These are involuntary perceptual experiences that happen in the absence of external stimuli. This means people with schizophrenia may see or hear things that others cannot, and they have no control over this. Hearing voices si a core symptom of schizophrenia, but hallucinations can also be visual, olfactory (smell) and somatosensory (touch).

  • Experiences of influence, passivity or control: This refers to the subjective experience that our thoughts, feelings and actions are being controlled by external forces. ICD-11 refers to these unusual feelings as experiences, noting that delusional beliefs may develop as a way of explaining them. E.G: We believe aliens are implanting thoughts into our brains because we feel that our thoughts do not belong to us.

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Positive Symptoms
  • Delusions: fixed beliefs that conflict with reality. While some delusions relate to everyday situations, such as believing you are being monitored by the police, delusions can also be more bizarre, such as believing aliens are recruiting people to populate a new universe.

  • Other symptoms: Disorganised thinking and behaviour, people may often lose their 'train of thought', This can lead to incoherent (muddled) speech and word salads, where ideas become jumbled.

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Negative Symptoms
  • As noted above, negative refers to an absence of thoughts, feelings or behaviours that would generally be considered psychologically normal. 
  • E.G people with schizophrenia sometimes experience flat affect, meaning they do not experience typical emotional highs and lows. 
  • They may experience avolition, which means they are not able to carry out goal-directed behaviours, like getting ready to go out or organising the ingredients to cook a meal.
  • Other examples of negative symptoms include alogia (lack of spoken language), asociality (social withdrawal) and anhedonia (inability to experience pleasure).

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Age of onset
  • The prevalence of schizophrenia is similar for males and females (about 0.3-0.7 per cent), but the age of onset is usually earlier for males (early to mid-20s) compared with females (late 205). Late onset (i.e. from age 40) is more common in females. 

  • This disorder is rarely diagnosed in children under the age of 13 as the symptoms can overlap with various other disorders, such as autism and obsessive-compulsive disorder. This can make diagnosis difficult and unreliable.

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Case Study: Aneja et al. (2018)

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  • ICD-11 people only need to display symptoms for 1 month, DSM-5 requires 6 months. Access treatment rapidly
  • Detailed case history - he showed symptoms before onset (loss of interest, social withdrawal...)  increases validity of diagnosis


  • Use of young children (he was unable to provide consent)
  • ICD-11 also makes it difficult to diagnose due to symptom overlap. E.G catatonia and hallucinations may be experienced by people with depression but can be caused by drug withdrawal, stress and sleep deprivation. - Reduces reliability of diag.
  • Lacks cultural validity - Child was from India, stigma of mental health - could've made condition worse. Cannot generalise findings to other cultures.

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Investigating Delusions with Virtual Reality
VR has been used for the following:

- Fear of flying
- Fear of heights
- Fear of public speaking
- Medical training

It is thought that experiencing the situations which they have developed these fears and issues from in VR will help those in their experiences in the real world.

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Investigating Delusions with Virtual Reality
  • Freeman (2008) believes that virtual reality ‘allows one of the key variables in understanding psychosis, social environments, to be controlled, providing exciting applications to research and treatment’. Freeman outlines seven applications of this method, two of which are symptom assessment and treatment.

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Key Study: Freeman et al. (2003) Aim
  • Freeman wanted to explore the potential use of VR to help with the challenges of assessing symptoms and developing treatment for schizophrenia.

  • Typically symptom assessment had relied on an interviewer and patient in a clinical setting discussing behaviour. This relies on self report which is means that a patient may not tell the truth.

  • Using VR a situation can be manipulated and genuine reaction to it can be observed. This can ensure that paranoid thoughts and behaviour are genuine.

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Key Study: Freeman et al. (2003) Procedure
  • A trial was conducted on 200 students - a non-clinical population. Prior to use of VR, these participants were assessed on levels of paranoid thinking, emotional distress and other cognitive and social traits. The Green Paranoid Thoughts Scale was used

  • They were immersed in the virtual world using the VR equipment. A library scene or underground scene was used with neutral avatars. For example, Ps went on a virtual 5 minute ride on the underground. They were asked to report their experiences during the 'ride'.

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Key Study: Freeman et al. (2003) Results
- Those who scored highly on the questionnaire assessment of paranoia experienced high levels of persecutory ideation during the VR trail.

- This meant that they were more likely to make comments such as 'lady sitting next to me laughed at me when I walked past' rather than positive or neutral comments such as 'getting on with my own business'.

- In related laboratory studies, Freeman reports that those individuals who experience auditory hallucinations in the real world also experience them in the VR environment.

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Key Study: Freeman et al. (2003) Conclusions
  • VR can provide a standardised assessment of symptoms. Patients reactions to avatars can assess severity of paranoid delusions.

  • Can be used to measure physiological correlations of behaviour.

  • Can be used to predict patients behaviour to social factors alongside pre-measures of personality factors.

  • Can identify differential predictors e.g. other predictors like levels of social anxiety or co-morbidity of psychological issues can be assessed in terms of reaction in the VR setting.

  • Environmental predictors for anxiety can be detected e.g. size of room can be safely manipulated to see effects on social paranoia. Casual factors for anxiety can be detected.

  • Treatments can be developed: Patients can be educated about personal triggers. Patients can experience anxiety provoking situations in VR to lessen anxiety in real world.

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  • A large sample of 200 students was used. It identifies how pre-tests of paranoia in a non-clinical sample relate to experiences of paranoia using VR.

  • The specifically designed VR programme adopts a standardised approach to assessment. It shows how participants actually behave rather than relying on self report. This is of use when generalising to real patients.

  • A wide range of situations can be created using VR which can be tailored to needs of individual patients. It therefore has good real world application in identifying and treating some symptoms of schizophrenia.

  • Patient may experience side effects e.g. nausea and headaches.

  • Sampling bias: All patients were from a London university, the findings cannot be generalised outside population

  • Limited trials have been conducted on real patients. Use of a non clinical population limits generalisability to real patients.

  •  Ecological validity can be questioned. Although very realistic, Ps know that it is not a real situation. Anxiety would be higher in the real world.

  •  This method relies on self-report. VR users are asked to make comments about their experiences, this may lead to response bias.

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Issues and debates
  • Application to everyday life:
  • VR trials can be used to assess patient symptoms, as well as potentially identify causal factors and treatment strategies. However, the method has not been used extensively in clinical populations at the time of Freeman's writing, meaning it is yet to be determined whether it can replace conventional clinical interviews and questionnaires in diagnosing schizophrenia.

  • Cultural bias: 
  • The diagnosis of schizophrenia and other psychotic disorder is particularly open to criticism because it relies on culturally based expectations of what constitutes normal social behaviour. This is important because some cultures are more tolerant than others in what is considered normal with regard to hearing voices. There are also social norms around interacting in public, levels of eye contact and personal space which vary among cultures. Use of VR in diagnosing symptoms would need to take such factors into consideration to avoid creating biased interpretations of individuals' behaviour and comments.

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Schizophrenia: Biological (Genetic)
  • Genetic basis: schizophrenia runs in families: Strong relationship between genetic similarity of family members and likelihood of both developing schizophrenia. Often tested family/twin studies 

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Schizophrenia: Biological (Genetic)
  • Gottesman and Shields (1972) examined the records of 57 schizophrenics (40% monozygotic twins and 60% dizygotic twins) between 1948 and 1964.

  • In this sample, they found concordance rates (the probability of a twin having schizophrenia if the other twin has it) of 42% for monozygotic twins and 9% for dizygotic twins. This again provides evidence for a genetic link for schizophrenia.

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Biological - Genetic (Gottesman, 1966)
  • Since the siblings in both groups (MZ and DZ) were raised in the same household, the higher concordance rate in MZ twins was thought to be due to the greater amount of shared DNA.

  • Concordance rates (where both twins are schizophrenic) for schizophrenia increases between people as the genetic similarity increases.  

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Biological - Genetic (DiGeorge & COMT)
  • sometimes problems arise during cell division and whole strands of DNA become duplicated or even deleted; this causes a 'printing error in the biological manual' and can increase a person's risk of developing schizophrenia. For example, in DiGeorge syndrome, a strand of DNA containing 30-40 genes is deleted from chromosome 2.  1 in 4 people with this condition develop schizophrenia, compared to less than 1 in 100 people without DiGeorge syndrome. 

  • This has been linked to the deletion of a specific gene called COMT (Kim et al., 2020). This gene codes for an enzyme which breaks down neurotransmitters such as dopamine. This suggests that the absence of this gene could be partially responsible for the complex neurochemical imbalances that seem to underpin the symptoms of schizophrenia.

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Biological - Genetic (DiGeorge & COMT)
Generalisability - Can the findings be generalised to the wider population? E.g. Sample size, participants, cultural differences etc 
Reliability - If the researcher was to repeat the study again, could they generate the same results? 
Application - How can we apply the results to the real world and Psychological practise? 
Validity - did the study measure what it set out to measure? How true were the results to the real world? 
Ethics - Were there any ethical guidelines broken? What could the researcher do to overcome theses issues? 

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Biological - Biochemical (Dopamine hypothesis)
  • Suggests schizophrenia is caused by changes in dopamine function in the brain. An excess of dopamine causes the neurones that use dopamine to fire too often and therefore transmit too many messages, overloading the system and causing the symptoms of schizophrenia

  • Lindstroem et al. (1999) gave 10 people with and 10 people without schizophrenia L-Dopa, a drug that increases dopamine levels, and found that those with the disorder took up the drug quicker than those without schizophrenia.

  • Excess dopamine levels have been found to cause greater neural activity associated with the positive symptoms such as ............... and .................. 

Slide 24 - Tekstslide

Evaluating: Biochemical (Dopamine hypothesis)
  • Reductionism vs holism?
  • The idea that a single neurotransmitter is responsible for schizophrenia is no longer accepted.

  • Determinism vs free will?
  • Explanation is deterministic as It suggests that the workings of the brain are responsible for the symptoms of schizophrenia.

  • Nature vs Nurture?
  • Does not take into account the environment e.g nurture debate, and 

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Exam question
  • Jameela has schizophrenia. She experiences hallucinations and is very socially withdrawn. Her doctor explains to her family that her symptoms may be caused by an imbalance of dopamine in her brain. Explain the dopamine hypothesis with reference to Jameela's symptoms? (4 marks)

  • 2 marks for explaining 
  • 2 marks for referencing to the example

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Cognitive Explanation
  • Suggests that schizophrenia is a result of ‘faulty information processing’ due to specific ‘cognitive deficits’. It claims that schizophrenia sufferers have problems with meta-representation, which is involved with giving us the ability to reflect upon our thoughts, behaviours and feelings, as well as giving us the sense of self-awareness

  • Frith (1992) took this further and argued that several symptoms of schizophrenia could be explained by mentalising impairment (impairment of the ability to attribute mental states such as thoughts, beliefs and intentions to people, allowing an individual to explain, manipulate and predict behaviour) and that theory of mind is impaired in schizophrenics.

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  • Helps to explain individual differences in mental health by highlighting differences in ways people process information

  • Supporting research usually takes a nomothetic approach. The data is then used to draw conclusions and generalise findings to wider population. 

  • Fails to take into account individual differences between people. Using case studies would allow for a more idiographic approach

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  • Outline one evaluation point for two of the genetic explanations of schizophrenia
  • Genetic/Biochemical/Cognitive

  • Which explanation do you think is the strongest in explaining schizophrenia and why?

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According to the ICD-11, how long should a person show core symptoms to be diagnosed with schizophrenia?
At least one year
At least one week
At least one month
At least six months

Slide 30 - Quizvraag

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What is a potential weakness of using VR in assessing paranoia?
Wide range of situations can be created
Real world application in identifying symptoms
Patients may experience side effects like nausea and headaches.
Limited trials on real patients

Slide 31 - Quizvraag

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Excess dopamine levels have been found to cause greater neural activity associated with the positive symptoms of schizophrenia, such as:

Slide 32 - Quizvraag

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What is the main claim of the cognitive explanation for schizophrenia?
Schizophrenia is a result of social factors
Schizophrenia is caused by genetic factors
Schizophrenia is a result of 'faulty information processing'
Schizophrenia is a result of chemical imbalances

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Write down 3 things you learned in this lesson.

Slide 35 - Open vraag

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.
Write down 2 things you want to know more about.

Slide 36 - Open vraag

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.
Ask 1 question about something you haven't quite understood yet.

Slide 37 - Open vraag

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.