schizophrenia Flashcards
what are the main symptoms of schizophrenia
- hallucination
- delusion
- distorted thinking
- control
- emotional volitional changes
define hallucinations
auditory , visual or kinaesthetic. person hears voices in their head , talking to them or to each other
define delusion
these are false beliefs and take many forms , grandeur or persecution
define emotional and volitional changes
emotions are flat and the person has no energy or initiative
positive symptoms means
that it adds something to a person eg hallucination
negative symptoms means
takes away from a person eg lack of emotional expression , less responsive to drugs
normal functions are limited
what are the subtypes of schizophrenia
paranoid catatonic disorganised undifferentiated residual
describe paranoid as a sub type of schizophrenia
there is a preoccupation with one or more delusion or frequent auditory hallucinations . none of the following is prominent , disorganised speech , disorganised or catatonic behaviours or flat inappropriate behaviours
describe catatonic as a subtype of schizophrenia
at least 2 of the following are present , immobility , stupor , excessive motor activity, extreme negativism , echolalia
describe disorganised as a subtype of schizophrenia
all of the following are prominent , disorganised speech, disorganised behaviour, flat effect
describe undifferentiated as a subtype of schizophrenia
criteria A symptoms are present , but the criteria are not met for the paranoid, disorganised or catatonic type
describe residual as a subtype of schizophernia
there is an absence of prominent delusions, hallucinations, disorganised speech, catatonic behaviours. there are negative symptoms or two or more symptoms listed in criteria A in an attenuated form
three types of diagnostic assessments and symptoms
DSM5
A characteristics symptoms- two or more of the following , each present for one month period, delusions, hallucinations, disorganised speech , catatonic behaviour , negative symptoms
b social/ occupational dysfunction - a significant proportion of the time since the onset of the disturbance , one or more major areas of functioning such as work, interpersonal relations, or self care are marked below the level achieved before onset
c duration - continuous signs of the disturbance persists for at least 6 months .this 6 months period must include at least one month of symptoms that meet criteria A
describe reliability in relationship to diagnosing schizophrenia
consistency of diagnosis
Reliability concerns the consistency of symptom measurement and affects diagnosis in 2 ways:
Test –retest reliability
Inter-rater reliability
Read et al (2004) reported test retest reliability of schizophrenia diagnosis to have only a 37% concordance rate. However if up to date classification systems are used there is 98% concordance Jakobsen et al (2005) ( Danish patients, operational criteria)
Evaluation: DSM is more reliable as symptoms in each category are more specific
reliability is improving, the classification systems also provide a common language for practitioners, which leads to better treatments. (collaboration of ideas)
describe reliability in relationship to diagnosing schizophrenia
consistency of diagnosis
For a valid diagnosis to occur schizophrenia should be a separate disorder from all others.
There are several ways validity can be assessed
Reliability
Predictive validity: if diagnosis leads to successful treatment, then diagnosis is seen as valid
Descriptive validity: patients should differ in symptoms from patients with other disorders
Aetiological validity: schizophrenics should have the same cause for the disorder
Research is Rosenhan (1973) Summarise Rosenhan so that you can use it in essays.
Evaluation: Bentall (2003) diagnosis says nothing about its cause and is therefore invalid.
describe gender bias in relation to diagnosing schizophrenia
The tendency for diagnostic criteria to be applied differently to males and females and for there to be differences in the classification of the disorders.
It is accepted that males and females are equally vulnerable to the disorder but some argue that clinicians(mostly male) have misapplied the criteria to women.
Gender bias also exists when considering types of symptom. Males tend to show more negative symptoms and women have higher recovery and lower relapse Haro (2008).
Females tend to have a first onset later than males, 25-36yrs, males 18-25yrs.
Eval: females developing schizophrenia later than males as well as a post menopausal schizophrenia suggests there are different types of schizophrenia to which males and females are vulnerable, questioning the validity of the diagnostic criteria.
describe culture bias in relation to diagnosing schizophrenia
The tendency to over-diagnose members of other cultures as suffering from schizophrenia
In Britain, people of Afro Caribbean descent are much more likely than white people to be diagnosed as schizophrenic and be compulsorily confined to secure units.It is suggested that this is due to white psychiatrists perceiving black schizophrenics are more dangerous that white schizophrenics.
Stress levels in ethnic minorities, a possible cause??
32 out of 89 confinements in closed wards in Bristol hospitals were of non white patients, which is much greater that the proportion of non white people in society Ineichen (1984)
Evaluation: It is only Afro Caribbean people are the only ethnic minority to experience higher levels of diagnosis, so schizophrenia is unlikely to be cuased by stress levels for ethnic minorities.
describe co morbidity in relation to diagnosing schizophrenia
The presence of one or more additional disorders or diseases occurring simultaneously with schizophrenia
When one or more other disorders occur simulataneously with schizophrenia problems in the reliability of the diagnosis can occur. Depression is commonly suffered from alongside schizophrenia.
Co morbidity also raises issues of descriptive validity, having simultaneous disorders suggests that schizophrenia may not actually be a separate disorder
Buckley et al (2009) 50% had co morbid depression, 15% had panic disorder, 47% had substance abuse. Illustrating reliability and validity issues
Evaluation: the biggest problem in reliably diagnosing schizophrenia is separating it from bipolar disorders. Mood changes are common in both but for schizophrenics do not meet the criteria for separate diagnosis of bipolar disorder
describe symptom overlap in relation to schizophrenia diagnosis
The perception that symptoms of schizophrenia are also symptoms of other mental disorders.
In diagnosing schizophrenia, symptoms of the disorder are often also found with other disorders, which makes it difficult for clinicians to decide which disorder someone is suffering from. Other disorder with similar symptoms: multiple personality disorder, schizoaffective disorder.
Autistic patients had some schizophrenia symptoms but no schizophrenics had autism symptoms Hewitt (2001).out of seven of the gene locations for schizophrenia, three of them overlap with bipolar disorder Ophoff et al (2011).
Evaluation: misdiagnosis due to symptom overlap can lead to years of delay in receiving the correct treatment.
describe the genetic explanation for schizophrenia
Family studies: if you have schizophrenia there is 5.6%chance that your parents have it, a 10% chance that one of your siblings will have it.
If both your parents suffer from schizophrenia there is a 46% chance that you will suffer from it aswell.
Family studies have confirmed that schizophrenia does run in the family. However the extent to which this is due to genetics or environmental influences is unclear
Twin or adoption studies have tried to solve the issue
within the biological explanation , the genetic explanation has what two types of studies
adoption and twin studies
the biological explanation includes
genetics
dopamine hypothesis
neurochemical
describe twin studies as part of the biological explanation for skitz
Monozygotic twins: 100% genes in common, one egg one sperm = 2 babies
Dizygotic twins:50% genes in common, two eggs two sperm
Average concordance from 5 studies: monozygotic 46% dizygotic 14% (Gottesman & Shields 1982)
describe adoption studies as part of the explanation for skitz
Adoption studies allow us to separate the environment influences from genetic influences
Typically the studies are of children adopted within weeks of birth
Hesston (1966) 47 schizophrenic mothers, their children were adopted within days by well mothers. 16% chance of children developing Schizophrenia
evaluations of genetic theory in biological explanations for skitz
Identical/monozygotic schizophrenic twins are rare and as such the sample size is small for twin studies
Concordance for MZ twins is 3X that of DZ twins BUT there is still 54% chance that one twin will not suffer from Schizophrenia.
46% concordance suggest high influence of Genotype.
describe the neurochemical explanation for skitz within the biological explanation
Investigation of neurotransmitters can be carried out in three ways
Evidence of metabolites in the blood or urine
Examination of post mortem brain tissue
Use of neuroimaging
Neurotransmitters (dopamine) and the enzyme responsible for their metabolism have been investigated in search for an explanation for schizophrenia
describe the dopamine hypothesis within the biological explanation of skitz
It was thought that excessive dopamine was the cause of schizophrenic symptoms
Evidence for this idea came from
Healthy people taking drugs which increase dopaminergic activity in the brain
Neuroleptic drugs that block dopaminergic reactions reduce psychotic symptoms
However this theory was difficult to support as post mortem studies didn’t show consistent evidence of high dopamine levels
It may have been that it was not the increase in dopamine levels that caused the symptoms but a heightened sensitivity of the receptors for dopamine that led to an abundance of the chemical and schizophrenic symptoms
Post mortem studies have shown increased D2 receptors in the brains of people with schizophrenia than normal brains
PET scans have shown increased D2 receptors in patients with schizophrenia
what is the updated theory for the dopamine hypothesis
Not all sufferers have high levels of dopamine, modern drugs have little dopamine blocking activity
High levels of dopamine in the mesolimbic system lead to positive symptoms
High levels of dopamine in the mesocortical system are associated with negative symptoms.
Kessler et al (2003) – differences in cortical dopamine levels were found between sufferers and non sufferers – suggesting its importance at onset
evaluation of the dopamine hypothesis
Issues with post mortem studies are cause or effect.
Major antipsychotic drugs block dopamine receptors, to infer from this that dopamine hyperactivity is the major cause of schizophrenia is to oversimplify. We now have a greater understanding of the interaction between neurotransmitter systems and that mapping these pathways is only just being explored.
