Introduction to schizophrenia Flashcards
what is schizophrenia
a severe mental disorder where contact with reality and insight are impaired, an example of psychosis
what is the classification of mental disorder
the process of organising symptoms into categories based on which symptoms frequently cluster together
what is the system for diagnosing schizophrenia
the clinical diagnosis for schizophrenia uses the DSM-5, where all 3 criteria needs to be reached:
criteria A - characteristic symptoms
criteria B - social/occupational dysfunction
criteria C - duration
what are the other diagnostic methods
the world health organisation recommends the ICD10, where two or more negative symptoms are sufficient for a diagnosis.
how does the ICD10 differ from the DSM-5
in the DSM-5 system one of the positive symptoms must be present under diagnosis whereas two or more negative symptoms are sufficient under the ICD10
what are positive symptoms of schizophrenia
atypical symptoms experienced in addition to normal experiences
what are hallucinations
a positive symptom of schizophrenia. they are sensory experiences that have either no basis in reality or are distorted perceptions of things that they are
what are delusions
a positive symptom of schizophrenia. they involve irrational beliefs that have no basis in reality, for example, a person believes that they are someone else or that they are a victim of a conspiracy
what are negative symptoms of schizophrenia
atypical experiences that represent the loss of a usual experience such as a loss of clear thinking or a loss of motivation
what is speech poverty
a negative symptom of schizophrenia. it involves reduced frequency and quality of speech
what is avolition
a negative symptom of schizophrenia. it involves a lack of motivation to carry out tasks and results in lowered activity levels
what are the three signs of avolition
Andreasen (1982) identified three signs of avolition: poor hygiene and grooming, lack of persistence in work or education and lack of energy
what is the evidence for good reliability in the diagnosis of schizophrenia (strength)
a psychiatric diagnosis is said to be reliable when different diagnosing clinicians reach the same diagnosis for the same individual (inter-rater reliability)
Osorio et al (2019) report excellent reliability in 180 individuals using the DSM-5
pairs of interviewers achieved inter-rater reliability of +.97 and test-rest reliability of +.92
why is there low validity in the diagnosis of schizophrenia (limitation)
Cheniaux et al (2009) had two psychiatrists independently asses the same 100 clients using ICD10 and DSM-5 criteria and found that 68 were diagnosed with schizophrenia under the ICD system and 39 under the DSM.
this suggests that schizophrenia is either over or under diagnosed according to the diagnostic system.
suggests low criterion validity
what is a counter-point for the low validity
in the Osorio et al study there was excellent agreement between clinicians when they used two measures to diagnose schizophrenia both derived from the DSM system
this means that the criterion validity for diagnosing schizophrenia is actually good, provided it takes place within a single diagnostic system
what is symptom overlap in schizophrenia (limitation)
when conditions share symptoms
most prevalent with bi-polar disorder as both positive and negative symptoms are present
this can lead to misdiagnosis or perhaps the conclusion that they are not separate conditions
this reduces validity further
what is co-morbidity (limitation)
if conditions occur together, alongside one another
this questions the validity of the diagnosis and classification as they may actually be a single condition
about half diagnosed with schizophrenia also had a diagnosis of depression or substance abuse (Buckley et al)
this means schizophrenia may not exist as a distinct condition
why is there gender bias in the diagnosis of schizophrenia (limitation)
since the 1980s men have been diagnosed with schizophrenia more commonly than women (ratio of 1.4:1, Fischer and Buchanan 2017)
women are less vulnerable than men, perhaps because of genetic factors
women are also likely to be underdiagnosed because they have closer relationships and hence get support (Cotton et al 2009)
this means women may not be receiving treatment and services that might benefit them
why is there culture bias in the diagnosis of schizophrenia (limitation)
some symptoms have different meanings in different cultures, in Haiti hearing voices is associated with ancestors
british people of african-carribean origin are up to 9 times as likely to recieve a diagnosis as white british people (Pinto and Jones 2008) although people living in africa are not, ruling out a genetic vulnerability.
leads to an overinterpretation of symptoms in black people.
this means that african-carribean people may be discriminated against
