Schizophrenia Flashcards
overview of schizophrenia
- Diagnosis and Classification
2.Biological explanations
3.Psychological explanations
- Drug therapy
5.Psychological treatments
6.Interactionist Approach
What is schizophrenia (classification and diagnosis)
Schizophrenia is a type of psychosis, a severe mental disorder in which thoughts and emotions are so impaired that contact is lost with external reality
(includes positive and negative symptoms)
-must be diagnosed by a “clinical interview” with a psychiatrist + assessment tests to see if symptoms match with those listed on classification index of mental illness (DSM-V)
What are examples positive symptoms of schizophrenia
- reflect excess or distortion of normal functioning
HALLUCINATIONS (a sensory experience in which a person can see, hear, smell, taste or feel something that is not there)
1. Auditory H (external voices commanding them to act/ commenting on one’s actions)
2. Visual H (perception of colours, shapes that are not present or of a person)
DELUSIONS (erroneous beliefs that involve misinterpretation of experiences)
-sufferer able to bring reason to support their delusion despite it being bizarre/ absurd
PERSECUTORY D (being spied upon)
DELUSIONS OF CONTROL (believe external forces control their thoughts etc supernatural)
- DISORGANISED SPEECH (incoherent speech, result of abnormal thought process)
- GROSSLY DISORGANISED (inability to initiate tasks resulting in difficulties in daily living) CATATONIC BEHAVIOUR (reduced reaction to immediate environment, rigid motor activities)
What are examples of negative symptoms of schizophrenia? ( reflect a reduction/ lossnof normal functions, persist even during low/ absent positive symptoms)
- SPEECH POVERTY (change in patterns of speech)
-brief empty replies to questions, lessening of speech fluency, difficulty in spontaneously producing words
- fewer clauses, shorter utterances, associated with long illness - AVOLITION (inability to carry out normal daily activities, little interest in social activities)
-sharply reduced motivation
(a) poor hygiene
(b)lack of persistence in education/work
(c)lack of energy
Affective flattening - reduction of intensity of emotional expression
Most common used classification systems are DSM and ICD (FOR DIAGNOSIS)
Diagnostic and Statistical Manual (2013)
Criteria A: two or more symptoms (only 1 when delusions are bizarre, inc voice commenting)
Criteria B: Social Dysfunction
(interpersonal and self-care below the level achieved prior to onset)
Criteria C: Duration (continuous signs of disturbance over 6 months inc those in Criteria A) non-active periods, limited to negative symptoms or symptoms in reduced form (odd beliefs)
Why is classification and diagnosis of schizophrenia so important?
- full understanding ensures that we know what symptoms are, accurately identify
- accurate identification leads to right people having treatment, inaccurate ones led to misdiagnosis
- common condition, full understanding enables them to try to live their lives normally
Diagnostic reliability refers to the consistency (a diagnosis of schizophrenia must be repeatable)
-must be able to reach the same conclusions at 2 different points in time (test-retest reliability) different clinicians must reach the same conclusions (inter-rater reliability)
which is assessed by the degree of positive correlation between scores
-however schizophrenia only has a score of 4 when it has to be 8
Validity (whether an observed effect is a genuine one)
-is the diagnosis of the patient as a schizophrenic accurate reflection of the disorder
How is the Rosenhan Study relevant to the diagnosis of SCHZ
-showed how flawed and poor the classification and diagnostic process was
-was supposed to be standardised but actually was open to interpretation, more subjective
-checked for inter-rater reliability, it was very poor
Reliability -> cultural differences in diagnoses
-African Americans living in UK more likely to be diagnosed, but no info showing it is a genetic trait
-is a result of different social norms
-in African cultures, hearing voices from ancestors is a normal phenomenon (different views on external influence and intervention)
-the experience of hearing voices are different. Interviewed 60 adults with schizophrenia (20 in Ghana, US, India)
-US ones violent and hateful
-Ghana India positive, “playful” or advice
-cultural variation may continue on outcome of condition
“ethnic culture hypothesis’” -> social structure in ethnic minority means individual experiences less stress and fewer symptoms
HAVING A FULL UNDERSTANDING OF VARIATIONS IN EXPERIENCE OF SCHZ MUST BE ESSENTIAL TO HELP ALL PATIENTS (have variations documented)
validity of the diagnosis of SCHZ
1. problem of symptom overlap
(can not identify symptoms belong to what)
2. co-morbidity
(patient has two identifiable conditions or more, make the decision to treat one that is more serious)
- positive and negative symptoms might also be found in other disorders (depression and BPD) ex. people with DID have more SCHZ symptom than schizophrenics
2.affect validity of diagnosis
2 or more conditions can occur at the same time. (substance abuse, anxiety and symptoms of depression) 50% of patients experience co-morbid depression (OCD)
Gender bias affecting the diagnosis (gender of individual influences chance if being accurately diagnosed)
-more men have been diagnosed
research testing gender bias
-patients described as male or no gender (56% diagnosed) labelled as female (20%diagnosed)
gender of clinician and gender of patient might impact diagnosis
-ICD and DSM criteria developed using “male norms” -> women might be mis-diagnosed
Biological explanations for SCHZ
- genetics
2.dopamine hypothesis
3.neural correlates
- Gottesman conducted family studies to show the prevalence of schizophrenia between family members
Monozygotic twins (100%DNA) compared to dizygotic twins (50%DNA) (higher concordance rates for MN shows greater support for genetics)
Findings:
MZ twins + children with both schz parents (46%)
DZ+ one parent schz (13%)
Briefly outline what typical antipsychotics do
REDUCES DOPAMINERGIC TRANSMISSION
dopamine antagonists in that they bind to but do not stimulate dopamine receptors (reducing symptoms of schizophrenia)
-combat positive symptoms of schizophrenia (hallucinations as products of overactive dopamine system)
Briefly outline what atypical antipsychotics do
carry low risk of extrapyramidal side effects, beneficial effect on negative symptoms and cognitive impairments
It would be useful to establish what the genetic influence is, but research did not show ONE SPECIFIC IS ENTIRELY RESPONSIBLE
-schz is polygenic (involves different gene) and is heterogenous (involves different combinations of genes)
-Human Genome Project -> a large sample was available to indicate link between particular genes and schz in the past
Findings:
108 separate genetic variations are implicated
-> long way from being to identify candidate genes
Evaluation of role of genetics in developing schz
ALL SUGGESTING THAT THERE IS A GENETIC VULNERABILITY TO SCHZ
strong evidence from Gottesman and Shields
-> alternative reason for development (environment they share) MZ likely share every aspect of their lives (nature vs nurture) reduces the validity of the genetic link
(uncommon to encounter twins with schz, the small sample size in research studied, inappropriate to generalise to a wider population)
-> try to gain greater clarity on whether genetics or environment is the main cause BY DOING ADOPTION STUDIES (controlling environment by not sharing with schz relative)
Tienari -> 164 adoptees with mother diagnosed with schz
6.7% of them diagnosed with schz
2% of control group (non-schz mother) diagnosed with schz
Dopamine hypothesis -> involves area of neurotransmitter function -> link between dopamine function and schizophrenia (neural correlate)
-schz is result of faulty functioning of neurotransmitter function
- Hyperdopaminergia
excess of dopamine in the subcortex and Broca’s Area (associated with positive symptoms such as speech poverty and auditory hallucinations) - Hypodopaminergia
unusually low levels of dopamine in the prefrontal cortex (thinking decision-making)
links to negative symptoms
evaluation: supported by evidence from drug treatments
A meta-analysis (systematic review identifying an aim and searching for research studies that addressed similar hypotheses) (improve estimates of an effect size of the association and increase observational power) 212 studies concluded all antipsychotic drugs tested in studies were more effective than placebo (positive and negative symptoms) by reducing the effects of dopamine.
But antipsychotic drugs do not alleviate hallucinations in about 1/3 of people
(H and D are present despite dopamine levels being normal) abnormal dopamine production does not explain schz in all patients
Ripke’s study of genetic variations linked to schz found genetic codes associated with function of other neurotransmitters
dopamine levels are a common variant BUT NOT THE ONLY NEUROTRASMITTER INVOLVED
other neurotransmitter systems might also produce positive symptoms associated with schizophrenia
the dopamine function theory is too reductionist (focus on explaining schz of 1 neurotransmitter in isolation)
dopamine interest with other nt such as serotonin
-better to adapt a holistic approach
-should study combined effects of several neurotransmitters, can be supported by evidence of effectiveness of drug treatments that act on several nt
Neural correlates of schizophrenia (variations in brain structure with intention of finding links between particular parts of brain and behaviours associated with =ve and -ve symptoms in schz)
Sis have low functioning of the prefrontal cortex (cognitive deficits linked with -ve symptoms) poor connections with other brain parts
there is a positive correlation between nerve connection between PFC and hippocampus in SZs -> poor memory and cognition, poor hippocampi function also -> dopamine release
neural correlates pt.2 prefrontal cortex grey and white matter
Grey matter:
SZs have less grey matter in temporal and frontal lobes
White matter:
SZs have reduced myelination (conduct nerve impulses faster) in white matter esp in connection of PFC to the hypothalamus
evaluation of neural correlates (meta-analysis) (relevance)
19 studies comparing SZs with healthy control group
findings
-high reduction in grey matter volume (frontal temporal lobes) active in first stages of the illness
-identifying variations in brain structure using scanning techniques might predict late development of SZ (treated more effectively)
general evaluation
biological explanations suggest an alternative way that schz is implicated through gene mutation (sperm cells)
-prevalence of schz when gene mutation occurs -> positive correlation between paternal age and risk of schz
(older parents have an increased risk of sperm mutation)