Schizophrenia - Classification Flashcards
What is Schizophrenia?
- Schizophrenia is a type of psychosis, a severe mental disorder characterised by a profound disruption of cognition and emotion so that contact with external reality and insight are impaired. This affects a person’s language, thought, perception, emotions and even their sense of self.
- Schizophrenia is the most common psychotic disorder, affecting 1% of the population at some point in their lifetime.
- The symptoms can interfere severely with everyday tasks, so that many sufferers end up homeless or hospitalised. It has been estimated that no more than 1 in 5 individuals recover completely, even with treatments available that can relieve many symptoms.
- It can occur any time in life, but usually occurs late in adolescence or early adulthood. The peak of incidence onset is 25-30 years.
Classification v Diagnosis
Classification = organising symptoms into categories based on which symptoms cluster together in sufferers i.e. categorising the symptoms of schizophrenia.
Diagnosis = deciding whether someone has a particular mental illness using the classifications.
Symptoms of schizophrenia
- Positive symptoms = atypical symptoms experienced in addition to normal experiences (an excess or distortion of normal functioning). These include hallucinations and distortions.
- Negative symptoms = atypical experiences that represent the loss of a usual experience (a diminution or loss of normal functioning).
Positive symptoms
- Hallucinations; disturbances of perception in any of the senses, that either have no basis in reality or are distorted perceptions of things that are - the most common are auditory hallucinations (hearing voices) and many schizophrenics report hearing voices or seeing people telling them to do something e.g. harm themselves or others, or commenting on their behaviour
Delusions = firmly held irrational beliefs that have no basis in reality; common types include -
1) Delusions of persecution - the belief that others want to harm, threaten or manipulate you
2) Delusions of grandeur - the belief that they are an important individual, even god-like and have extraordinary powers e.g. believe they are Jesus Christ
3) Delusions of control - the belief that their body is under external control
4) Delusions of reference - the belief that events in the environment appear to be directly related to them
Negative symptoms
- Avolition - a lack of purposeful, willed behaviour, or the reduction, difficulty on inability to start and continue with goal-directed behaviour i.e. actions performed to achieve a result, as people with schizophrenia often have a sharply reduced motivation to carry out a range of activities and results in lowered activity levels e.g. no longer being interested in going out and meeting friends, poor hygiene, lack of persistence in work or education, sitting at home all day and doing nothing
- Speech poverty (alogia) - limited speech output with limited, often repetitive content, involving reduced frequency and quality of speech, sometimes accompanied by a delay in the sufferer’s verbal responses during conversation; they know the words but cannot spontaneously produce them
Other symptoms of clinical schizophrenia
- Disorganised thinking - the feeling that thoughts have been inserted or withdrawn from the mind, and in some cases the person may believe that their thoughts are being broadcast for others to hear
- Affective flattening - a reduction in the range and intensity of emotional expression, including facial expression, voice tone, eye contact and body language
- Social / Occupational dysfunction - for a significant portion of the time since the onset of the disturbances, one or more major areas of functioning such as work, interpersonal relations or self-care are markedly below the level achieved prior to the onset
- Catatonic behaviour - this refers to bizarre and abnormal motor movements e.g. holding the body in a rigid stance, moving in a frenzied way, peculiar facial movements and copying the movements of others
- Anhedonia - a loss of interest or pleasure in almost all activities, or lack of reactivity to a normally pleasurable stimuli
Classifications and diagnosis of schizophrenia
The DSM-5 and ICD-10 are the methods used to diagnose and classify schizophrenia.
- Does not have one single defining characteristic; it is a cluster of symptoms which sometimes appear unrelated
- The two major systems for classification of mental disorders are the World Health Organisation’s International Classifications of Disease edition 10 (ICD-10) and the American Psychiatric Associations’ Diagnostic and Statistical Manual edition 5 (DSM-5); the ICD-10 is mainly used in Europe and the DSM-5 mainly used in America, which differ slightly in their classification of Schizophrenia
- In the DSM-5 system, two of the positive symptoms must be present for diagnosis, but only one if delusions are bizarre or hallucinations consist of a voice keeping a running commentary of people’s thoughts or behaviour or multiple voices are present
- Requires signs of disturbance to be continuous for at least 6 months, with one or major areas of functioning such as work, interpersonal relations or self-care must be lower than how they were before onset for a significant period of time also
- In the ICD-10 system, two or more negative symptoms are sufficient for diagnosis or one positive symptom
- The ICD-10 also recognises a range of subtypes of schizophrenia, such as paranoid, characterised by powerful hallucinations and delusions, but relatively few other symptoms, and hebephrenic schizophrenia which involves primarily negative symptoms
- Previous DSM editions recognised subtypes of schizophrenia, but this has been dropped in DSM-5
Reliability and validity in schizophrenia diagnosis
Reliability -
- Consistency of the classification system to assess the symptoms of schizophrenia, with the level of agreement on the diagnosis by different psychiatrists across time and cultures and stability of diagnosis over time given no change of symptoms
Validity -
- Whether the research has measured what it intended to measure, which is the extent to which schizophrenia is a unique syndrome with characteristics, signs and symptoms
- Validity is how accurate a diagnosis is as a unique syndrome with characteristics, signs and symptoms.
4 issues with reliability and validity in the diagnosis and classification of schizophrenia:
- Symptom overlap
- Co-morbidity
- Cultural differences/cultural bias
- Gender bias
Key Terms:
Gender bias, cultural bias, co-morbidity, symptom overlap and culture
Gender bias - the tendency to describe the behaviour of men and women in psychological theory and studies in such a way that might not represent accurately the symptoms of either one of the genders
Cultural bias - refers to the tendency to ignore cultural differences and interpret all phenomena through the ‘lens’ of one’s own culture (own cultural assumptions) which is therefore mistakenly assumed that findings derived from studies carried out in one culture can be applied all over the world
Co-morbidity - the occurrence of two illnesses or conditions together e.g. someone has schizophrenia and depression - if this occurs frequently, it calls into question the validity of schizophrenia as a distinct mental illness
Symptom overlap - when two or more conditions share symptoms, and if this occurs frequently, it questions the validity of schizophrenia
Culture - the rules, customs, morals that bind a group of people together and define how they are likely to behave
Assessing the reliability and validity of schizophrenia diagnosis and classification - symptom overlap
- There is considerable overlap between the symptoms of schizophrenia and other conditions, despite the claim that the classification of positive and negative symptoms would make for more valid diagnoses (symptom overlap).
- For example, schizophrenia and bipolar disorder share positive symptoms like hallucinations and delusions. This calls into question the validity of the classification and diagnosis of schizophrenia as a unique syndrome with its own characteristics, signs and symptoms.
Assessing the reliability and validity of schizophrenia diagnosis and classification - co-morbidity
- Co-morbidity refers to the extent that two or more conditions occur together. Co-morbidities are common among patients with schizophrenia e.g. substance abuse, anxiety and depression.
- Where two conditions are frequently diagnosed together, it calls into question the validity of the classification and diagnosis of both illnesses. In terms of diagnosis, if many patients are diagnosed with both conditions, psychiatrists may not be able to tell the difference between the two conditions.
- In terms of classification, it may be that if one illness (e.g. severe depression) looks a lot like schizophrenia and vice versa, they might be better seen as a single condition.
Research evidence - Symptom overlap
1) Serper et al (1999)
- They assessed patients with co-morbid schizophrenia and cocaine abuse, cocaine intoxication on its own and schizophrenia on its own
- They found that despite there being considerable overlap in symptoms between the two conditions, it was actually possible to make an accurate diagnosis
- suggests that symptom overlap did not affect the validity of a diagnosis and clinicians can tell the difference between the illnesses.
- This suggests that the issue of symptom overlap may not be as important an issue as has previously been suggested.
2) Ketter (2005):
- Points out misdiagnosis due to symptom overlap can lead to years of delay in receiving treatment, during which time suffering and further degeneration can occur, as well as high suicide levels
- So symptom overlap can have serious consequences and focusing on fixing this issue could save money and lives
- suggests that the classification and/or diagnosis may lack validity and that this has serious consequences for patients with schizophrenia.
Research evidence - co-morbidity
Buckley et al (2009):
- They concluded that around half of patients with a diagnosis of schizophrenia also have a diagnosis of depression (50%), substance abuse (47%) and PTSD also occurred in 29% of cases and OCD in 23%
- This calls into question the validity of the classification and diagnosis of both illnesses. In terms of diagnosis, if many patients are diagnosed with both conditions, psychiatrists may not be able to tell the difference between the two conditions.
- In terms of classification, it may be that if one illness (e.g. severe depression) looks a lot like schizophrenia and vice versa, they might be better seen as a single condition.
Assessing the reliability and validity of schizophrenia diagnosis and classification - cultural bias
- Research suggests that there is a significant variation between cultures when it comes to diagnosing schizophrenia. For example, African-Americans and English people of Afro-Caribbean origin are several times more likely to be diagnosed with schizophrenia.
- Given that rates in Africa and the West Indies aren’t high, the diagnosis seems to be the result of cultural bias.
- Positive symptoms of hearing voices may be more acceptable in African cultures because of cultural beliefs in communication with ancestors. Therefore, people are more ready to acknowledge such experiences.
- When reported to a psychiatrist from a different cultural tradition, these experiences are likely to be seen as bizarre and irrational.
This calls into question the validity of diagnoses of schizophrenia as psychiatrists may impose their own cultural standards for schizophrenia onto those from other cultures (imposed etic) and so are biased towards what is ‘normal’ in their culture (ethnocentric). Therefore, the diagnoses may not be valid across cultures. - It also calls into question the reliability of diagnoses of schizophrenia as it suggests that there may not be agreement on the diagnosis by psychiatrists across cultures and so the methods may not be suitable for use across all cultures as there wouldn’t be consistent diagnoses/classifications.
- It suggests that patients can display the same symptoms but receive different diagnoses because of their ethnic background; i.e. a patient’s ethnicity makes it more or less likely that they will be diagnosed with schizophrenia.
- This potentially has long-term consequences, such as labelling and stigmatisation which could cause long-term problems in relationships, leading to a self-fulfilling prophecy
Research evidence for cultural bias
1) Copeland et al (1971):
- They gave a description of a patient to 134 US and 194 British psychiatrists - 69% of the US psychiatrists diagnosed schizophrenia but only 2% of the British gave the diagnosis of schizophrenia
- No research has found any cause or this, so it suggests that the symptoms of ethnic minorities are misinterpreted
- symptoms of schizophrenia may be misinterpreted rather than undiagnosed; poor inter-rater reliability / diagnostic validity
2) Escobar (2012):
- Pointed out that white psychiatrists may tend to over-interpret the symptoms of black people in diagnosis - such factors such as cultural differences in language and mannerisms, difficulties in relating between black patients and white therapists, and the myth that black people rarely suffer from affective disorders may be causing this problem
- Therefore, clinicians and researchers must pay more attention to the effects of cultural differences on diagnosis
- Escobar found that white psychiatrists over-interpret the symptoms of black people. Myth that black people rarely suffer from schizophrenia - validity issues
