Paper 3 - Schizophrenia Flashcards
Outline what is meant by Schizophrenia
Schizophrenia is a serious mental disorder suffered by about 1% of the world population. People from all cultures and levels of society develop schizophrenia- it is
the most common mental disorder accounting for up to 50% of all mental patients.
Schizophrenia affects thoughts processes and the ability to determine reality. Degrees of severity varies between sufferers: some encounter only one episode, some have persistent episodes but live relatively normal lives through taking medication, while others have persistent episodes, are non-responsive to medication and remain severely disturbed. Schizophrenia may be a group of disorders, with different causes and explanations.
Outline the different classification of schizophrenia
Schizophrenia does not have a single defining characteristic- it is a cluster of symptoms some of which appear to be unrelated. The two major systems for classification of mental disorders, are the World Health
Organisation’s International Classification of Disease edition 10 (ICD-10) and the American Psychiatric Association’s Diagnostic and Statistical Manual edition 5 (DSM5).
Outline the different editions of the classifications of schizophrenia
Previous editions of ICD and DSM recognised subtypes of schizophrenia (e.g. paranoid schizophrenia involved mainly powerful hallucinations and delusions). Both DSM-5 and ICD-10 have dropped subtypes because they tended to be inconsistent e.g. someone with a diagnosis of paranoid schizophrenia would not necessarily show the same symptoms a few years later
Define positive symptoms
Atypical symptoms experienced in addition to normal experiences
Outline the positive symptoms of schizophrenia
Hallucinations - These are unusual sensory experiences. Some hallucinations are related to events in the environment whereas others bear no relationship to what the senses are picking up from the environment.For example, voices heard either talking to or commenting on the sufferer, often criticising them. Hallucinations can be experienced in relation to any sense. The sufferer may, for example, see distorted faces or occasionally people or animals that are not there.
Delusions - Also known as paranoia, delusions are irrational beliefs. These can take a range of forms. Common delusions involve being an important historical, political or religious figure, such as Jesus or Napoleon. Delusions also commonly involve being persecuted, perhaps by government or aliens or of having superpowers. Another class of delusions concerns the body. Sufferers may believe that they or part of them is under external control. Delusions can make a sufferer of schizophrenia behave in ways that make sense to them but seem bizarre to others. Although the vast majority of sufferers are not aggressive and are in fact more likely to be victims than perpetrators or violence, some delusions can lead to aggression
The DSM-5 places its emphasis on speech disorganisation in which speech becomes incoherent or the speaker changes topic mid-sentence. Furthermore disorganised thinking can also be considered as a positive symptom for a sufferer of schizophrenia which can present as breaks or interpolations in the train of thought. Catatonic behaviour may involve the sufferer performing strange positions and movements, or long periods of motionlessness. They may display rigidity or excessive movement. In cases where people experience excitability as a symptom, they may move in an erratic and extreme manner
Define negative symptoms
Atypical experiences that represent the loss of a usual experience such as clear thinking or ‘normal’ levels of motivation
Outline negative symptoms as a classification in Schizophrenia
Avolition - This can be defined as losing the will to perform the behaviours necessary to accomplish purposeful acts, such as activities of daily life, goals, and
desires. Can also be described as finding it difficult to begin or keep up with goal directed activity i.e. actions performed in order to achieve a result. Sufferers of schizophrenia often have very reduced motivation to carry out a range of tasks and results in lowered activity levels, sometimes called ‘apathy’. Andreason (1982) identified 3 identifying signs of avolition; Poor hygiene and grooming, Lack of persistence in
work/education and Lack of energy
Speech poverty- Schizophrenia is characterised by changes in patterns of speech. Speech poverty can be defined as minimal verbal communication that lacks the additional unprompted content characteristic of normal
speech. The ICD-10 recognises speech poverty as a
negative symptom. This is because the emphasis is on
reduction in the amount and quality of speech. This is sometimes accompanied by a delay in the sufferer’s verbal responses during conversation.
Characteristic of the symptom is the tendency only to speak when prompted, and to provide very limited answers. For example, a person might respond to the question, “How did you feel when your mother yelled at you?” with “bad.” When prompted to provide more.
Define Reliability in diagnosis and classification
Reliability refers to the consistency of a classification system such as DSM e.g. to assess particular symptoms of schizophrenia. Reliability alone counts for nothing
unless these systems and scales are also valid.
Outline Validity in diagnosis and classification and how to test it
Validity refers to the extent that a diagnosis represents something that is real and distinct from other disorders and the extent that a classification system such as DSM accurately diagnoses schizophrenia.
One standard way to assess validity of diagnosis is concurrent validity (amount of agreement between two different assessments)
Outline Evidence investigating validity
Cheniaux et al (2009) found that inter-rater reliability amongst two psychiatrists was low. One diagnosed 26 out of 100 patients with schizophrenia using the DSM, and 44 out of 100 using the ICD. The other diagnosed 13 using the DSM and 24 using the ICD. Looking at the results from the Cheniaux et al. study above we can see that schizophrenia is much more likely to be diagnosed using ICD than DSM. This suggests that schizophrenia is either over-diagnosed in ICD or under diagnosed in DSM. Either way, this highlights an issue with concurrent validity. Different assessment systems do not arrive at the same diagnosis
Outline Reliability in diagnosis and classification and how to test it
Reliability means consistency of symptom measurement - an important measure being inter-rater reliability; this is the extent to which different clinicians agree on their assessments.
In the case of diagnosis inter-rater reliability means the extent to which two or more mental health professionals arrive at the same diagnosis for the same patients.
Outline Evidence investigating reliability
Cheniaux et al. (2009) had two psychiatrists independently diagnose 100 patients using both DSM and ICD criteria. Inter-rater reliability was poor, with one psychiatrist diagnosing 70 with schizophrenia according to DSM and ICD, and the other diagnosing 37 according to DSM and ICD. This evidence highlights weaknesses in the use of classification systems to diagnose schizophrenia. This is an issue as the external reliability is low as the psychiatrists failed to diagnose the patients consistently. This poor reliability is an issue for the diagnosis of schizophrenia. HOWEVER, It is important to note that Cheniaux research was carried out using the DSM-IV and not DSM-5 and evidence generally suggests that the reliability and validity of diagnoses has improved as classification systems have been updated.
Define symptom overlap
Symptom overlap is the perception that symptoms of schizophrenia are also symptoms of other mental disorders.
Outline symptom overlap and evaluate
Despite the claim that the classification of positive and negative symptoms would make for more valid diagnosis of schizophrenia, many of the symptoms of the disorder are often found with other disorders, which makes it difficult for clinicians to decide which particular disorder someone is suffering from. Read (2004) argued people diagnosed with schizophrenia have sufficient symptoms
of other disorders that they could also receive at least one other diagnosis. For example, Symptom overlap especially occurs with bipolar disorder, where negative symptoms e.g. depression and avolition are common symptoms, as well as positive symptoms e.g. hallucinations.
This highlights issues with the validity of trying to classify schizophrenia because a patient might be diagnosed as schizophrenic with the ICD, however, many of the same patients would receive a diagnosis of bipolar disorder according to DSM criteria. A consequence of this issue could mean that individuals are misdiagnosed which can lead to years of delay in receiving relevant treatment, during which time suffering and further degeneration of symptoms can occur for the individual.
Define co-morbidity
Co-morbidity is the phenomenon that 2 or more
conditions occur together.
Outline Co-morbidity and evaluate
One issue which impacts the reliability and validity of a diagnosis is comorbidity. This is when two or more conditions occur together (e.g. Depression and Bipolar). For example, Schizophrenia is commonly diagnosed with other conditions. Buckley et al. (2009) concluded that around half of patients with a diagnosis of schizophrenia also have a diagnosis of depression (50%) or substance abuse (47%). Post traumatic stress disorder also occurred in 29% of cases and OCD in 23%. Therefore, comorbidity is an issue for the diagnosis and classification of schizophrenia. Different diagnoses could be given for the same person; in one instance they could be diagnosed with schizophrenia, diagnosed with bipolar in another instance or they could be diagnosed with both conditions. This issue could lead to inconsistencies in diagnoses between clinicians in relation to which disorder is diagnosed e.g. Schizophrenia or Depression, creating problems for the reliability of diagnosis.
Furthermore, comorbidity is also an issue for the classification of schizophrenia. Having simultaneous disorders suggests that schizophrenia may not actually be a separate disorder. A consequence is that it lowers the (descriptive) validity of schizophrenia, which can make effective treatment for schizophrenia difficult to achieve.
Define Culture bias in diagnosis
Culture bias concerns the tendency to over-diagnose
members of other cultures as suffering from
schizophrenia.
Outline Culture bias in diagnosis and evaluate
Culture bias is another problem which affects the validity
of diagnosis. Although cross-cultural research of schizophrenia suggest a similar prevalence across races,
research has shown that Schizophrenia, despite culturally
formulated updates to diagnostic manuals, is repeatedly
diagnosed at a higher rate in the African American population.
Research by Cochrane (1977) reported the incidence of schizophrenia in the West Indies and Britain to be similar, at around 1%, but that people of Afro-Caribbean origin are 7 times more likely to be diagnosed with schizophrenia when living in Britain. Considering the incidence in both cultures is very similar this suggests that higher diagnosis rates are not due to a genetic vulnerability, but instead may be due to a cultural bias
Although there is not one explanation determining why African Americans are overrepresented. Two possible speculations are:
* Clinician bias - unconscious process stemming from stereotypes and biases which results in misdiagnosis (Schwartz, 2014).
* Under diagnosis of other disorders (Depression/Bipolar) in African Americans could contribute to the over-diagnosis of Schizophrenia.
Gara et al (2019) found that African American men with severe depression tend to be misdiagnosed with schizophrenia in comparison to other racial groups. The findings suggest that clinicians put more emphasis on psychotic than depressive symptoms in African-Americans, which skews diagnoses toward schizophrenia even when these patients show similar depressive and manic symptoms as white patients.
This is an issue as it suggests a lack of validity in diagnosing schizophrenia in people of African-American origin as differences in symptom expression are overlooked or misinterpreted by clinicians. The consequence of the misdiagnosis is that it prevents them receiving the optimal treatment for their disorder and puts them at risk of the side effects of medication taken for schizophrenia, such as diabetes and weight gain
Define Gender bias in diagnosis
The tendency for diagnostic criteria to be applied differently to male and females and for there to be differences in the classification of the disorder.
Evaluate Gender bias in diagnosis
Some critics of the DSM diagnostic criteria argue that some diagnostic categories are biased towards pathologising one gender rather than the other. For example, Broverman et al. (1970) found that clinicians in the US equated mentally healthy ‘adult’ behaviour with mentally healthy ‘male’ behaviour, illustrating a form
of androcentrism. As a result there was a tendency for women to be perceived as less mentally healthy when they do not show ‘male’ behaviour. Also interestingly, some research has indicated that a psychiatrist’s gender might affect their ability to diagnose.
Loring and Powell (1988) randomly selected 290 male and female psychiatrists to read cases studies of patients’ behaviour and make a judgement on these people using standardised diagnostic criteria (e.g. DSM). When the patients were described as ‘male’ or no info about
gender was given, 56% of psychiatrists have a schizophrenia diagnosis. When patients were described as ‘female’, only 20% were given a diagnosis of schizophrenia. Interestingly, the gender bias was not as evident among the female psychiatrists, suggesting that diagnosis is influenced not only by gender of the patient but also the gender of the clinician.
There is also gender bias in the fact that when making diagnoses, clinicians often fail to consider that males tend to suffer more negative symptoms than women
(Galderisi et al., 2012) and women typically function better than men, being more likely to go to work and have good family relationships (Cotton et al. 2009).
This high functioning may explain why some women have not been diagnosed with schizophrenia when men with similar symptoms might have been; their better
interpersonal functioning may bias clinicians to under-diagnose the disorder, either because symptoms are masked altogether by good interpersonal functioning, or
because the quality of interpersonal functioning makes the case seem too mild to warrant a diagnosis.
These misconceptions could be affecting the validity of a diagnosis as clinicians are not considering all symptoms. This can be an issue and can lead to men and women
who experience similar symptoms being diagnosed differently.
Clinicians also have tended to ignore the fact that there are different predisposing factors between males and females, which give them different vulnerability levels at
different points of life, which may impact the validity of diagnosis. The first onset occurs in males between 18-25 years whereas, females between 25-35 years. This
difference may be related to differences in the types of stressoras both sexes experience at different ages and to age-related variations in female menstrual cycle, which tends to be overlooked during diagnosis
Briefly outline what is in the biological explanations for schizophrenia
There are several biological explanations for schizophrenia, which see the disorder as determined by physiological means. The biological factors focused on here are genetics, abnormal dopamine functioning and neural correlates. Although causes of schizophrenia are not fully understood, research does indicate that biological factors play a role in the development of the disorder.
Outline the General Genetic Link Theory in the biological explanations for schizophrenia
The genetic explanation sees schizophrenia as transmitted through genes passed on to individuals from their families. We share a different % of genetics with our relatives depending on how genetically similar we are to them. For example, we share 50% of our genetics with 1st degree relatives e.g. parents, siblings (purple on graph). We share 25% with 2nd degree relatives e.g. grandparents, aunts/uncles (pink on graph) We share 12.5% with 3rd degree relatives e.g. cousins, great grandparents (green).
Investigations that look at the genetic similarity between family members and how it is associated with the likelihood of developing schizophrenia are good evidence for understanding the influence that genes play. However, we have to be careful when using this evidence as showing a genetic link because family members tend to share aspects of their environment as well as many of their genes
Gottesman (1991) conducted a large-scale family study and found a strong relationship between the degree of genetic similarity and shared risk of schizophrenia. For example, 48% concordance rate in MZ twins in comparison to 17% in DZ twins.
Outline more specific genetic explanation in the biological explanations of schizophrenia
It is not believed that there is a single ‘schizophrenic gene’, but that several genes are involved, which increase an individual’s overall vulnerability to developing schizophrenia this is a polygenic approach to schizophrenia i.e. it requires a number of factors to work in combination. Because different studies have identified different candidate genes it also appears that schizophrenia is aetiologically heterogenous, i.e. different combinations of factors can lead to the condition.
Ripke et al. (2014) carried out a huge study combining all previous data from genome-wide studies (i.e. those looking at the whole genome as opposed to particular genes) of schizophrenia. The genetic make-up of 37,000 patients was compared to that of 113,000 controls; 108 separate genetic variations were associated with increased risk of schizophrenia.
Genes associated with increased risk included those in the brain and in tissues with an important role in immunity, as well as those coding for functioning of a number of neurotransmitters including dopamine. This supports the overall idea of a biological causation in the disorder