Classification of Schizophrenia

• according to the DSM what is schizophrenia classified as?

  a psychosis, as the sufferer has no concept of reality
• what are positive symptoms?


  symptoms that are not usually present in a normal person
• what are some positive symptoms?

  • Delusions: false beliefs that are firmly held despite being completely illogical, or for which there is no evidence.
  • Hallucinations: involve disturbances in perception (rather than disturbances in thought). They are false perceptions that have no basis in reality.
• what are negative symptoms?

  • cause a decline in functioning. Negative symptoms appear to reflect a loss of normal function.
• what are some negative symptoms?

  • speech poverty: inability to speak properly, characterised by lack of ability to produce fluent words
  • avolition: reduction, difficulty, or inability to start and continue with goal-directed behaviour.
• what is reliability and how does it relate to classification and diagnosis?

  • extent to which a finding is consistent
  • It is the extent to which psychiatrists can agree on the same diagnosis when independently assessing patients (inter-rater reliability).
  • For a classification system to be reliable, the same diagnosis should be made each time.
  • Therefore different psychiatrists should reach the same decision when assessing a patient.
• what is validity and how does it relate to classification and diagnosis?

  • extent to which we are measuring what we are intending to measure.
  • In the case of an illness like schizophrenia we have to consider the validity of the diagnostic tools; for example, do different assessment systems arrive at the same diagnosis for the same patient?
• method of Rosenhan (1973)

  • 8 confederates acted as pseudopatients, going to 12 different hospitals. The real participants were the hospital staff who did not know about the experiment.
  • The pseudopatient called the hospital for an appointment. When they arrived they complained of hearing voices saying “empty”, “hollow” and “thud”.
  • Once on the ward, the pseudopatients stopped pretending symptoms, behaved normally and wrote observations. Pseudopatients were discharged only when they convinced staff that they were sane.
• results of Rosenhan (1973)

  • On admission, staff diagnosed 11 pseudopatients with schizophrenia, and one with manic-depression.
  • Staff never detected their sanity.
  • Nurses reported their behaviour as showing “no abnormal indications”, but did interpret their behaviour in the context of their diagnosis (see conclusion).
  • The average hospital stay was 19 days. All pseudopatients were discharged with diagnosis of schizophrenia ‘in remission’. 35 real patients detected sanity (e.g., saying “You’re not crazy”).
• what is comorbidity?

  • more than one disorders or diseases that exist alongside a primary diagnosis, which is the reason a patient gets referred and/or treated
  • Where two conditions are frequently diagnosed together it calls into question the validity of the classification of both illnesses.
• evaluation of comorbidity

  • 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 occurred in 29% of cases and OCD in 23%, showing that schizophrenia commonly occurs alongside other mental illnesses and the disorders are co-morbid.
• cultural variations in classification and diagnosis of schizophrenia

  • Copeland et al. (1971) 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 for this, so it suggests that the symptoms of ethnic minorities are misinterpreted.
  • This calls into question the reliability of the diagnosis of schizophrenia as it suggests that patients can display the same symptoms but receive different diagnoses because of their ethnic background
• evaluation of culture in the classification and diagnosis of schizophrenia (!)

  • One issue is that positive symptoms such as the hallucination or hearing voices may be more acceptable in African cultures because of cultural beliefs in communication with ancestors, and therefore people are more ready to acknowledge such experiences. When reported to a psychiatrist from a different culture these experiences might be seen as bizarre and irrational as the psychiatrists are culturally biased towards what is ‘normal’ in their culture and therefore are ethnocentric unknowingly
• evaluation of culture in the classification and diagnosis of schizophrenia (2)

  • Escobar (2012) has pointed out that White psychiatrists may tend to over-interpret the symptoms of Black people during diagnosis. Such factors 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
• gender bias in the classification and diagnosis of schizophrenia

  • 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.
• evaluation of gender bias in classification and diagnosis of schizophrenia (1)

  • Gender bias also occurs due to clinicians failing to consider that males tend to suffer more negative symptoms than women and have higher levels of substance abuse, or that females have better recovery rates and lower relapse rates. These misconceptions could be affecting the validity of a diagnosis as clinicians are not considering all symptoms.
• evaluation of gender bias in the classification and diagnosis of schizophrenia (2)

  • Clinicians also ignore that there are different predisposing/risk factors between males and females, which give them different vulnerability levels at different points in life. This can possibly explain the gender difference in the onset of schizophrenia.
• evaluation of gender bias in the classification and diagnosis of schizophrenia (3)

  • Loring and Powell (1988) randomly selected 290 male and female psychiatrists to read two case articles of patients’ behaviour and then asked them to offer their judgement on these individuals using standard diagnostic criteria. When the patients were described as ‘male’ or no information was given about their gender, 56% were given a diagnosis of schizophrenia. However, when the patients were described as ‘female’, only 20% were given a diagnosis of schizophrenia.
• symptom overlap in the classification and diagnosis of schizophrenia

  • 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.
  • For example, schizophrenia and bipolar disorder both share positive symptoms like delusions and negative symptoms like abolition.
  • This lack of distinction calls into question the validity of both the classification and diagnosis of schizophrenia.
• evaluation of symptom overlap in the classification and diagnosis of schizophrenia (1)

  • Serper et al. (1999) 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 symptom overlap in patients with schizophrenia and cocaine abuse, it was actually possible to make accurate diagnoses, showing that symptom overlap did not affect the validity of a diagnosis and clinicians can tell the difference between the illnesses.
• evaluation of symptom overlap in the classification and diagnosis of schizophrenia (2)

  • Ketter (2005) points out that misdiagnosis due to symptom overlap can lead to years of delay in receiving relevant treatment, during which time suffering and further degeneration can occur, as well as high levels of suicide- so symptom overlap can have serious consequences. Focusing on fixing this issue could save money and lives.
• evaluation of symptom overlap in the classification and diagnosis of schizophrenia (3)

  • Ophoff et al. (2011) assessed genetic material from 50,000 participants to find that of seven gene locations on the genome associated with schizophrenia, three of them were also associated with bipolar disorder, which suggests a genetic overlap between the two disorders and a reason for the symptom overlap. The fact that there is this genetic overlap between the two disorders suggests that gene therapies might be developed which simultaneously treat different illnesses.