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SCHIZOPHRENIA: DIAGNOSIS AND CLASSIFICATION - Coggle Diagram

- - - - Read et al. (2004) discovered that the test-retest reliability of schizophrenia diagnosis was only a 37% concordance rate. However, given the increasing reliability of diagnosis over time, we must consider that they provide practitioners with a common language which allows for communication of research ideas and findings which will lead to increased understanding of schizophrenia resulting in more effective treatment and more reliable diagnosis.
  - - - Beck et al. (1962) found a concordance rate of 54% between the diagnoses of 153 patients, whereas Soderberg et al. (2005) found 81% concordance rate when the DSM classification system was used, suggesting that classification systems have become more reliable over time, as the classification systems have been updated.
      - Nilsson et al. (2000) reported a 60% concordance when the ICD classification system was used, which implies that the DSM is the more reliable of the two. This is likely due to the fact that the symptoms outlined by the DSM for each category are much more specific than the ICD. (ICD - two negative symptoms; DSM - one positive symptom needed for diagnosis)
      - Generally, schizophrenia is regarded as having better reliability in diagnosis (measured to be 81%) compared to that of anxiety disorders (63%), although the validity of those diagnoses is considered to be poor.
- - - - CO-MORBIDITY EVALUATION
        
        Schizophrenics often comorbidly suffer from substance abuse, resulting in lower levels of functioning, increased hospitalisations, lower compliance with medication, making treatment harder.
        
        Schizophrenia must be distinguished from manic depression, as mood changes often involve periods of mania and depression but may not meet the requirements for a diagnosis of bipolar disorder./
        
        Controversy over whether or not comorbidities are sub-types of the disorder given the high proportion of comorbidity in schizophrenics
        
        Jeste et al. (1996) Schizophrenics with comorbid conditions are excluded from research, despite the majority of sufferers belonging to this group. Ergo, results in issues generalising findings from said research to the wider population, affecting which treatments can be used
      - CO-MORDIBITY RESEARCH
        
        Goldman (1999) - 50% of schizophrenics had a comorbid medical condition such as substance abuse or polydipsia (excessive thirst).
        
        Sim et al. (2006) - 32% of 142 hospitalised schizophrenics had an additional mental disorder, showing the problem that comorbidity can create in achieving a reliable and valid diagnosis of schizophrenia.
        
        Buckley et al. (2009) - estimated that 50% of schizophrenics also had depression, 15% a panic disorder, 23% OCD, 29% PTSD, and 47% substance abuse.
  - - - SYMPTOM OVERLAP EVALUATION
        
        Depending on whether the DSM-V or ICD-10 is consulted for diagnosis, the patient may have bipolar disorder or schizophrenia. The symptom overlap of schizophrenia and bipolar disorder (with positive symptoms, eg. delusions, and negative symptoms, eg. avolition) could suggest that they may not be two conditions but one.
        
        Ketter (2005) claims that misdiagnosis due to symptom overlap can lead to years of delay in receiving treatment, furthering the suffering and degeneration that occurs, as well as high levels of suicide.
        
        To ascertain which particular disorder someone is suffering from is to analyse their grey matter content of the brain, as schizophrenics experience reduced grey matter while bipolar sufferers do not.
      - SYMTOM OVERLAP RESEARCH
        
        Serper et al. (1999) - assessed comorbid schizophrenia and cocaine abuse; cocaine abuse; and schizophrenia. Although there was significant symptom overlap, it was possible to make accurate diagnoses.
        
        Konstantareas and Hewitt (2001) - compared 14 autistic people to 14 schizophrenic people and found that no schizophrenics had symptoms of autism, but 7 of the autistic people had symptoms of schizophrenia
        
        Due to the genetic overlap of some disorders, gene therapy may be developed that can treat both disorders simultaneously.
        
        Ophoff et al. (2011) assessed genetic material of 50,000 participants to find that of the 7 gene locations associated with schizophrenia, 3 were also associated with bipolar disorder, suggesting a genetic overlap between the two disorders.
  - - - CULTURE BIAS EVALUATION
        
        Fernando (1988) states that people from ethnic minorities experience more stress, and thus have a higher proportion of schizophrenia than white people
        
        Cochrane (1983) claims that the only ethnic group to experience a disproportionate amount of diagnoses of schizophrenia is Afro-Carribean, which could be due to mothers having flu during pregnancy, which increases the risk of schizophrenia in the baby by 88%, especially in black people given they have lower immunity to flu
        
        Rack (1982) points out that in many cultures, it is considered normal and part of the grieving process to see and hear deceased people, whereas in many Western societies it would be considered to be a symptom of schizophrenia.
        
        Cochrane & Sashidharan (1995) argue that the poverty and social deprivation that immigrants suffer is what affects their mental health, however, most clinicians attribute their behaviour to their ethnicity.
      - CULTURE BIAS RESEARCH
        
        McGovern & Hope (1977) ⅔ of schizophrenic patients in Birmingham hospitals were second or third generation Afro-Caribbeans.
        
        Ineichen (1984) - 32/89 confinements in closed hospitals in Bristol were non-white which is suggestive of a tendency to see non-white schizophrenics as more dangerous.
        
        Whaley (2004) - suggests the discrepancy between amount of American white schizophrenics (1.4%) and black schizophrenics (2.1%) is due to cultural bias as ethnic differences of symptom expression are overlooked or misinterpreted, indicating a lack of validity in diagnosing schizophrenia cross-culturally
        
        Cochrane (1977) found that the West Indies and Britain had similar rates of schizophrenia (1%), but that Afro-Caribbean origin people are seven times more likely to be diagnosed with schizophrenia in Britain than white people. Either they experience more stressors living in Britain or invalid diagnoses are made due to cultural bias.
  - - - GENDER BIAS EVALUATION
        
        The fact that women tend to develop schizophrenia 4-10 years later as well as post-menopausal schizophrenia could mean that there are different types to which men and women are vulnerable, calling into question the validity of the diagnosis.
        
        Research findings suggest that it would be worthwhile having separate diagnosis criteria for men and women, however this would cast doubt on the validity of schizophrenia as a separate disorder.
        
        Differences in the ages at which men and women first develop schizophrenia could be caused by differences in the types of stressors both sexes experience at different ages and to age-related variation in the menstrual cycle.
        
        Cotton et al. (2009) found that women with schizophrenia tend to function better than their male counterparts, maintaining a professional life and good familial relationships, and so their high functioning could account for why women are not diagnosed when men with similar symptoms are.
      - GENDER BIAS RESEARCH
        
        Kulkarni et al. (2001) - the female sex hormone estradiol was effective in treating schizophrenia in women when added to antipsychotic therapy, which suggests there may be different protective and predisposing factors in male and female vulnerability to schizophrenia that clinicians are not considering at diagnosis
        
        Lewin et al. (1984) - if clearer diagnostic criteria were applied, the number of female diagnoses reduces, suggesting a gender bias in the first criteria. Supported by Castle et al. (1993) who found that using more restrictive diagnostic criteria that the male incidence of the disorder was more than half that of women.
        
        Reichler-Rossler & Häfner (2000) - males have more severe negative symptoms, reinforced by Galderisi et al. (2012) finding males scored higher for negative symptoms. Also Hambrecht & Häfner (2000) found men had higher levels of substance abuse and Haro et al. (2008) reporting that the relapse rates are higher in men but recovery rates are higher in women, suggests a gender bias in clinicians not considering such important factors when making diagnoses.
- - - - Allardyce et al. (2006) reported that because there is a lot of difference between patients in what groupings of symptoms they experience, it is not possible to diagnose schizophrenia as a separate disorder, which suggests diagnoses are not valid.
      - This was supported by Jansson & Parnas (2007) who reviewed 92 studies that applied different definitions of of schizophrenia to the same patient samples to find that both ICD-10 and DSM-IV, while showing moderate levels of reliability, indicated only low measures of validity, again suggesting schizophrenia may not exist as a separate condition.
  - - - Mason et al. (1997) tested the ability of four different classification systems to predict the outcome of the disorder over 13 years in 99 schizophrenic patients, and found that more modern classification systems had high predictive validity, especially if symptoms only lasting at least six months were considered. This suggests that predictive diagnosis has improved over time, as classification systems have been updated.
      - Birchwood & Jackson (2001) argue that as 20% of schizophrenics recover and never have another episode, but 10% are so affected they commit suicide, there is too much variety in the outcomes of schizophrenia for predictive validity to be supported
  - - - Jäger et al. (2003) found that it was possible to use ICD-10 to distinguish 951 cases of schizophrenia from 51 persistent delusional disorders, 116 cases of acute and transient psychotic disorders and 354 schizoaffective disorders, with schizophrenic patients having more pronounced negative symptoms and lower overall functioning. This suggests that diagnosis has high descriptive validity.
  - - - Baillie et al. (2009) surveyed 154 British psychiatrists to find that other than an agreement as to the influence of genetics, biochemical abnormalities and substance abuse, they had widely differing views on the causes of schizophrenia. This suggests that the aetiological validity of schizophrenia is low, though that of depression was even lower.