schizophrenia Flashcards
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what is schizophrenia
. serious mental disorder
. characterised by severe disruptions in psychological function
. includes delusions, hallucinations, disorganised speech and behaviour
. all symptoms that disrupt social/occupational functioning
how is schizophrenia classified
. using either the DSM-5 or the ICD-10 (international classification of diseases, produced by WHO, contains all disease)
hoe do the DSM and the ICD differ in classifications of sz
. DSM requires at least one positive symptom where ICD does not
. ICD recognises a range of subtypes of sz but DSM had these removed
what are the DSM-5 criteria for classification of sz
A) two symptoms must be present for sig portion of time during 1 m period
- delusions,
- hallucinations
- disorganised speech
- grossly disorganised/ catatonic behaviour
- negative symptoms
B) reduction in 1 or more major areas of functioning
C) continuous signs of disturbance must persist for at least 6 m, at least 1m of active symptoms
what are the two main types of sz
. type 1 sz - positive symptoms
. type 2 sz - negative symptoms
what are the positive (type 1) symptoms of sz
. any behavioural excess
- hallucinations : unusual sensory experiences, 70% of p suffer auditory hallucinations
- delusions: irrational beliefs with no basis in reality, delusions of persecution and delusions of grandeur are most common
what are the negative (type 2) symptoms of sz
. any behavioural defecit
- speech poverty: decrease in fluency and productivity, produce fewer words ue to difficulty spontaneously producing them, often speak with repetetive content or slurring
- avolition: a lack of purposeful/willed or goal orientated behaviour, to be classified, there must be a reduction in self-initiated involvement in activities available to p
what is reliability in diagnosis
. the consistency in diagnosis
. in sz, wether there is agreement in diagnosis of sz by different psychiatrists across time and cultures
. known as inter rater reliability
. can also be test-retest reliability in wether diagnostic tests are consistent on different occasions
what is co-morbidity
. refers to the presence of one or more disorders/diseases simultaneously occurring with sz
. e.g. substance abuse (47%), anxiety (15%), depression (50%)
. suggests sz may not be a seperate disorder
. could lead to professionals giving different diagnosis to same individuals
what is the issue of culture bias
. the extent to which diagnostic system reflects beliefs about what is viewed as normal in predominantly white cultures
. reduces validity of diagnostic system
. both DSM and ICD developed in west, both lack cultural relativism
. affects reliability of diagnostic system, massive variation in diagnosis of sz across cultures, when us and uk clinicians giviven same description of patient diagnosis of sz was 60% us and only 2% uk
. means diagnosis was unreliable across cultures
what is validity in diagnosis and classification of sz
. teh extent to whixhmethods to measure sz are accurately doing so
. validity assessed using predictive validity, if diagnosis leads to succesful treatment, diagnosis seen as valid
what is gender bias in diagnosis and classification of sz
. occurs when the accuracy of a diagnosis is dependant on the gender of an individual, diagnostic criteria may be gender biased (it is, its based off male behaviours) or judgements made on stereotypical beliefs about gender
. men are diagnosed more often than women with sz
. women may have better social support
. #feminism male psychiatrists have been proven to diagnose men at a higher rate (56% to 20%) due to biases in diagnostic criteria that base typical behaviours off male behaviours meaning women go undiagnosed and are likely to be diagnosed far later
. this bias did not exist in female psychiatrist
. i hate men
. people of african descent far more likely to be diagnosed as well
what is symptom overlap
. occurs when symptoms of sz are also found in other disorders
. makes it difficult for, clinicians to accurately decide om a diagnosis
what are the weaknesses of sz classification and diagnosis
. only has weaknesses icl
. W relaibility - 2 psychiatrists independantly diagnosed 100 p, found inter rater reliability to be poor
- however recent reliability has been increasing, up to 97% in studies using DSM-5
- also criteria provides more understanding for clinicians
. W co morbidity - 50% of ps have substance abuse or depression, difficult to accurately classify as sz or just result of these
- jesse et al found co morbid ps often excluded from research despite making up majority of ps
. w culture bias - in haiti, voices seen as communications from ancestors, africans in uk 9X morel ikely to recieve sz diagnosis, however african countries they arent so not genetic vulnerability
- however this could represent effects of poorer housing, unemployment and social isolation experienced by africans
. W validity - people diagnosed with sz rarely have same symptoms,some never appear to recover from disorder whilst many do
. W - gender bias - males more likely to be commited to looney bins w/ mild symptoms due to risk of social deviance, whereas females more likely to be voluntary, women go incorrectly/underdiagnosed based on gender rather than symptoms
. W symptom overlap - genetic overlap between bipolar and sz, 3 of 7 genomes associated w/ sz also ass with bipolar, both have pos and neg symptoms, may be derived of same condition rather than 2
- people w/ DID also often have more symptoms of sz than ppl diagnosed with sz, means all 3 could be part of the same disorder, reduces validity of diagnosis
what is the dopamine hypothesis (biological)
. states positive symptoms caused by overactive transmission of dopamine
. sz have abnormally high levels of D2 receptors on recieving neurons
. allows more dopamine to bind
. leads to problems with attention, perception, and thought
. excess d2 in brocas can cause auditory hallucinations
. low d2 in prefrontal associated with negative symptoms
