introduction to schizophrenia Flashcards
2 major systems for classification of mental disorder
- ICD-10 (international classification of disease) - world health organisation
- DSM-5 (diagnostic & statistical manual) - american psychiatric association
how do DSM-5 and ICD-10 differ in diagnosis of schizophrenia
differ slightly in classification of schizophrenia
eg. in DSM-5 one of the positive symptoms must be present for diagnosis, in ICD-10 two or more negative symptoms are sufficient for diagnosis
define positive symptoms
additional experiences beyond those of ordinary existence
examples of positive symptoms
- hallucinations
- delusions
describe hallucinations
- unusual sensory experiences
- some related to events in environment
- others have no relationship to senses being picked up from environment
- experienced in relation to any sense
describe delusions
aka paranoia
- irrational beliefs
- can take range of forms
- common: delusions of grandeur (important figure) or persecution
- may believe they are under external control = behave differently to others
define negative symptoms
loss of usual abilities & experiences
examples of negative symptoms
- affective flattening
- avolition
- speech poverty (alogia)
- anhedonia
define affective flattening
- lack or ‘flattening’ of emotions
- voice becomes dull/monotonous
- face has constant blank appearance
define avolition
- ‘apathy’
- finding it difficult to begin/keep up with goal-directed activity (to achieve result)
- schizophrenic people often have reduced motivation to carry out range of activities
who identified 3 signs of avolition & what are they
andreasen (1982):
- poor hygiene/grooming
- lack of persistence in work/educaiton
- lack of energy
what is inter-rater reliability measured by
kappa score
0 = zero agreement
0.7+ = generally good agreement
1 = perfect inter-rater agreement
copeland (1971) - diagnosis fails to be consistent across cultures
method:
- gave 134 US & 194 british psychiatrists description of patient
- 69% of US psychiatrists diagnosed schizophrenia v. 2% british ones
shows:
- US more likely to diagnose schizophrenia
- huge difference between DSM-5 & ICD-10 as diagnostic tools
- potentially different training for psychiatrists
why is reliability low
- fluctuating symptoms
- different classification systems
- subjective reports of symptoms/difficulty assessing symptoms since patients rarely see doctor when experiencing episode
aim: ‘on being sane in insane places’ - rosenhan (1973) study
investigate whether mental health professionals could accurately differentiate between individuals who were genuinely mentally ill & those who weren’t
method: ‘on being sane in insane places’ - rosenhan (1973) study
- field experiment
- involved 8 pseuopatients (5 men, 3 women) = mentally healthy
- sought admission to 12 psychiatric hospitals across US
- presented single symptom: hearing in distinct voices saying ‘thud’, ‘empty’ or ‘hollow’
- upon admission, they behaved normally
- took notes about experiences covertly
- primary goal = gain release by convincing staff they were sane
findings: ‘on being sane in insane places’ - rosenhan (1973) study
- all pseudopatients admitted –> most with diagnosis of schizophrenia, except 1 (bipolar)
- hospital stays ranged 7 to 52 days (avg. 19 days).
- despite not showing symptoms post admission, behaviour often pathologized by staff eg. notes evidence of obsessive behaviour
- staff interactions minimal/depersonalizing (spent 6.8 min per day interacting)
- genuine patients noticed them as imposters (suspected journalists/researchers)
