schizophrenia- classification and diagnosis Flashcards
How prevalent is schizophrenia?Who does it most affect?
-serious mental disorder, affects 1% of population
-more common in males deem city in lower socio-economic groups
how is sz diagnosed?
identify symptoms and use classification system to identify disorder
classification of sz
identify symptoms that go together as part of a disorder
what are the two main classifications used for sz?
DSM-5
ICD-10
how does the DSM-5 classify sz?
ONE POSITIVE symptom must be present (delusions, hallucinations or speech disorganisation)
how does the ICD-10 classify sz?
two or more negative symptoms are sufficient for diagnosis (abolition and speech poverty)
what are positive symptoms of sz?
atypical symptoms experienced in addition to normal experiences
what does it mean by negative symptoms of sz?
loss of usual abilities and experiences
two examples of positive symptoms of sz
-hallucinations
-delusions
what are hallucinations?
unusual sensory experiences that have no basis in reality or distorted perceptions of real things. experienced in relation to any sense i.e. hearing voices or seeing people who aren’t there
what are delusions?
beliefs that have no basis in reality- make a person w/ sz behave in ways that make sense to them but are bizarre to others
i.e. beliefs ab being a very important person or the victim of a conspiracy
two examples of negative symptoms of sz
-speech poverty
-avolition
what is avolition?
-severe loss of motivation to carry out everyday tasks (work, hobbies, personal care)
-results in lowered activity levels and unwillingness to carry out goal-directed behaviours
what is speech poverty?
-reduction in the amount and quality of speech. may include delay in verbal responses in conversation
-DSM emphasises speech disorganisation and incoherence as a positive symptom
ao3 of sz: good reliability
-reliable diagnosis is consistent between clinicians (inter-rater) and between occasions (test-retest)
-Osório et al. (2019) report excellent reliability for sz diagnosis (DSM-5)- inter-rater agreement of +97 and test-retest reliability of +92
-means diagnosis of sz is consistently applied
ao3 of sz: low validity
-criterion validity involves seeing whether different procedures used to assess the same individuals arrive at the same diagnosis
-Cheniaux et al. (2009) two psychiatrists independently assess the same 100 clients 68 were diagnosed with sz with ICD and 39 with DSM
-means sz is either over, or under diagnosed, criterion validity low
ao3 of sz: co-morbidity w/ other conditions
-if conditions ofter co-occur then they might be a single condition. sz is commonly diagnosed w/ other conditions
-for example, buckley et al. (2009) concluded that sz is co-morbid w/ depression (50% of cases), substance abuse (47%) or OCD (23%)
-sz may not exist as a distinct condition
ao3 of sz: gender bias
-men diagnosed w/ sz more than often than women, in ratio of 1.4:1 (fisher and Buchanan (2017)
-this could be bc men are more genetically vuberble or more women have better social support, masking symptoms
-means women w/ sz not diagnosed so miss out on helpful treatment
ao3 of sz: culture bias
-some symptoms e.g. hearing voices, accepted in some cultures, e.g. Afro- Caribbean societies ‘hear voices’ from ancestors
-Afro-Carribean British men ten times more likely to receive a diagnosis as white British men, probably due to over interpretation of symptoms by uk psychiatrists
-means afro-carribean men living in uk appear to be discriminated against by a culturally-biased system
