Schizophrenia

• Schizophrenia is a severe mental illness where contact with reality and iSight are impaired
• positive symptoms

  atypical symptoms in addition to normal experiences
• negative symptoms

  atypical symptoms that result in the loss of normal experiences
• co-morbidity

  the occurrence of 2 illnesses or conditions together
• symptom overlap

  occurs when 2 or more conditions share symptoms
• positive symptoms

  hallucinations- things that seem really but only exist in mind

  delusions - an irrational belief that is false

  thought disorders- disordered way of thinking

  speech disorganisation- speaking incoherently and responding to questions with unrelated answers
• negative symptoms

  avolition- extreme lack of motivation

  speech poverty- reduction in amount and quality of speech

  disturbance of effect- irregulations of emotions
• diagnosis and classification

  In order to diagnose a specific disorder, we need to distinguish one disorder from another. We do this by identifying clusters of symptoms that occur together and classifying this as 1 disorder. Diagnosis is then possible by identifying symptoms and deciding what disorder a person has
• ICD-10 — international classification of disease 

  -At least 2 symptoms must be present, one of these must be a core symptom, such as delusions, thought insertion, thought withdrawal, hallucinations or thought disorder

  -Symptoms have to be present for most the time during a 1month period, positive and negative symptoms, but 2 or more negative is sufficient for diagnosis 
• DSM-5 — diagnostic and statistical manual edition

  -Must have experienced 2 of delusions, hallucinations, disorganised speech, negative symptoms, disorganised or catatonic behaviour 

  -Symptoms use persist for 6 months, with 1 month of active symptoms,with social or occupational deterioration, these problems must not attribute to another condition.
• Good reliability

  A psychiatric diagnosis is reliable when different diagnosing clinicians reach the same diagnosis for the same individual (inter-rater reliability)

  Prior to DSM-5, reliability for schizophrenia diagnosis was low but this has now improved.

  reports excellent reliability for the diagnosis of schizophrenia in 180 individuals using the DSM-5. Pairs of interviewers achieved inter-rater reliabilty of + 97

  This means that we can be reasonably sure that the diagnosis of schizophrenia is consistently applied.
• low validity 

  In general validity concerns whether we assess what we are trying to assess.

  One way to assess validity of a psychiatric diagnosis is criterion validity.

  two psychiatrists independently assessed the same 100 clients using ICD-10 and DSM-5 criteria and found that 68 were diagnosed with schizophrenia under the ICD system and 39 under DSM.

  This suggests that schizophrenia is either over or underdiagnosed according to the diagnostic system.

  Either way this suggests that criterion validity is low.
• limitation is co-morbidity 

  If conditions occur together a lot of the time then this calls into question the validity of their diagnosis and classification because they might actually be a single condition.

  one review found that about half of those diagnosed with schizophrenia also had a diagnosis of depression or substance abuse

  This is a problem for classification because it means schizophrenia may not exist as a distinct condition
• limitation is gender bias

  men have been diagnosed with schizophrenia more commonly than women

  One possible explanation for this is that women are less vulnerable than men, perhaps because of genetic factors.

  However it seems more likely that women are underdiagnosed because they have closer relationships and hence get support

  This leads to women with schizophrenia often functioning better than men. This underdiagnosis is a gender bias and means women may not therefore be receiving treatment and services that might benefit them.
• A limitation is culture bias

  Some symptoms of schizophrenia, particularly hearing voices, have different meanings in different cultures.

  in Haiti some people believe that voices actually are communications from ancestors.

  British people of African-Caribbean origin are up to nine times as likely to receive a diagnosis as white British people, although people living in African- Caribbean countries are not, ruling out a genetic vulnerability.

  This means that British African-Caribbean people may be discriminated against by a culturally-biased diagnostic system.