schizophrenia Flashcards
define schizophrenia
-schizophrenia is a serve mental disorder where contact with reality and insight are impaired. The sufferer may experience delusions or hallucinations
concordance rates of schizophrenia
Concordance rate of schizophrenia is higher in men than it is women – onset = late adolescence and early adulthood
5 types of schizphrenia
-Undifferentiated –> variation between symptoms and not fitting into a particular type
-Residual –> absence of prominent delusions. A presence of negative symptoms
-Paranoid –> preoccupied with false beliefs (delusions) about being persecuted or punished by someone. Their thinking, speech and emotions remain fairly normal
-Disorganized –> often are confused and incoherent with nonsensical speech. Their outward behaviour may be emotionless/falt etc. Disrupt their ability to perform normal daily activites like preparing meals etc
-Catatonic –> generally immobile physically and unresponsive to the world around them. Their bodies are often very rigid and stiff and unwilling to move. Increased risk of malnutrition etc
factors in the development of schizophrenia
-genetics (hereditary) –> passed from parents to children
-Brain chemistry –> imbalance of certain chemicals in the brain e.g dopamine. Dopamine levels affects the way the brain reacts to certain stimuli
-brain abnormality
-environmental factors -> poor social interactions, highly stressful situations or hormonal changes between teen and adult years
-no lab tests to diagnose schizophrenia so x-rays, blood tests etc are used to rule out a physical illness
-early diagnosis of schizphrenia can help avoid or reduce frequent relapses
positive vs negative symptoms
-positive symptoms = additions of something (delusions and hallcunations)
-negative symptoms = loss of something (speech poverty and avolition)
delusions
Delusions –> beliefs that have no basis in reality e.g belief there are victim of conspiracy.
-Paranoid delusions = someone is attempting to hurt them
-belief they have an imaginary power
hallucinations
Hallucinations –> experiencing sensations that arent caused by anything or anybody around the,. Most common is hearing voices. Feels very real to the person experiencing them. No basis is reality/distorted perceptions
speech poverty
Speech poverty –> Social withdrawal + difficulty in starting a conversation
-involves reduced frequency and quality of speech
avolition
Avolition –> loss of motivation to carry out tasks and lowered activity levels. No interest in socialising or hobbies
treatments
CBT + antipsychotics
DSM vs ICD
DSM-5 = 2 or more positive or negative symptoms of schizphrenia must be present for a diagnosis (American)
ICD-10 = range of subtypes for schizophrenia e.g paranoid (more international)
- Despite both requiring persistence of symptoms for at least 1 month, the DSM-V has more specific diagnostic criteria and so requires at least 2 or more of delusions, hallucinations, disorganized speech and catononic behaviour, whereas the ICD-10 takes a broader approach to diagnosis, simply stating that “the clinical picture is dominated by relatively stable, often paranoid delusions, usually accompanied by hallucinations
Rosenhan (1973)
-experiment into how accurate psychiatrists are at diagnosing abnormality
-involved the use of pseudopatients who stated they kept hearing the word thud in an attempt to gain admission to psych hospital. These patients told the doctors they felt fine and hospital staff failed to detect a single pseudopatients
-41/193 identified as pseudopatients
evaluating the reliability and validity of schizphrenia
-symptom overlap between symptoms
-co-morbidity
-gender bias = men more commonly diagnosed than women
-culture bias
reductionist nature of clinical diagnosis
Reductionist nature of clinical diagnosis = despite evidence that schizophrenia and bipolar disorder overlap they continue to be treated as separate illnesses
Critics argue there is no diagnostic boundaries in diagnosis
DSM-5 = eurocentric
strengths = validity and reliability
-classification = real life applications in treatment
limitations = validity and reliability
- There is a significant co-morbidity (high frequency of diagnosis of two disorders together) between schizophrenia and other mental health disorders, such as OCD and post-traumatic stress disorder, as suggested by Buckley et al (2009). These researchers found that 29% of their SZ patients suffered from post-traumatic stress disorder, whilst 50% suffered depression. Particularly in the case of depression, this suggests that if schizophrenia is so frequently diagnosed with other psychiatric disorders, then these two disorders may actually be the same, and so a more accurate and valid method of diagnosis would be to combine these two. Therefore, there are issues of validity in the diagnosis of SZ and attempting to differentiate its symptoms from that of other disorders.
-— There may be gender bias in the diagnosis of schizophrenia, as suggested by Longenecker et al (2010), who could not find an explanation for the sudden increase in the number of male SZ diagnoses made after 1980s. Cotton et al (2009) suggests that because there are no differences in genetic susceptibility for men and women in terms of SZ, then gender bias must be to blame. Dispositional traits of most women, such as high interpersonal functioning and being able to work even when suffering, means that such traits may mask the symptoms of schizophrenia or distort their severity so that they are not serious enough to call for a diagnosis. This means that the current system of the diagnosis of SZ does not account for these biases or differences in functioning between men and women, increasing the likelihood of inaccurate diagnoses.
— A second type of bias which may reduce the validity of the diagnosis of SZ is the problem of cultural bias, as suggested by Escobar et al (2012). For example, African Americans are far more likely to be diagnosed with SZ compared to patients belonging to Western cultures, due to their increased openness about admitting to certain SZ symptoms which may appear normal in their respective cultures. For example, the phenomenon of hearing voices may be considered a desirable sign of increased spirituality and connectedness with ancestors, and so may even be encouraged. However, both classification systems would view this as a hallmark characteristic of SZ and, combined with the potential distrust in African Americans that white psychiatrists may have, could increase the likelihood of false diagnoses.
-poor reliablity = Cheniaux et al 2009 = two psychiatrists independently diagnose 100ppl using both DSM and ICD. Inter-rater reliability was poor = 26 for DSM but 44 for ICD compared to 13 DSM and 24 ICD
biological explanations of schizphrenia
-genetic basis, dopamine hypothesis, neural correlates
genetic factors
-genetic component that predisposes people to the illness
-schizophrenia runs in familes suggesting evidence for a genetic link because family members tend to share the same aspects of their environment as well as their genes
-adoption studies = Heston 1966 = compared 47 adopted children whose biological mother has schizophrenia = higher risk even when raised in non-schizophrenia families
-higher associations of genetic similarity = higher likelihood of developing schizophrenia
-candidate genes = individual genes are believed to be associated with a level of inheritance. Schizophrenia is polygenic and aetiologically heterogenous (different combinations of factors can lead to the condition)
-Stephen Ripole et al (2014) –> genome-wide studies = 108 genetic variations associated with an increased risk of schizophrenia comparing 37,000 diagnosed and 113,000 controls
-genes affecting functioning of neurotransmitters such as doapamine
-10-20% concodrance rates in DZ twins but 40-50% in MZ twins
-Tierni (2004) = 5.8% in functional families and 36.8% in disfunctional families
Gottesman (1991)
Gottesman (1991) demonstrated a positive correlation between the increasing genetic similarity of family members and their increased risk of developing schizophrenia. The concordance rates are as follows = Monozygotic twins (48%), dizygotic twins (17%), siblings (9%) and parents (6%). This, particularly due to monozygotic twins sharing 100% of their genes, strongly suggests a genetic basis and the existence of candidate genes for schizophrenia. However, it is important to note that there are no 100% concordance rates, therefore demonstrating that there are environmental influences acting on the development of SZ e.g. the schizophrenogenic mother and dysfunctional thought processing.
strengths = genetic explanation
-multiple sources of evidence for genetic predisoposition = Gottesman 1991, adoption studies. Evidence suggests genetic susceptibility is very important
Limitations = genetic explanations
deteministic
diathesis stress
dopamine hypothesis
-dopamine is a neurotransmitter, causes neurons to fire in the brain
-original dopamine hypothesis stated that schizophrenia sufferes had an excessive amount of dopamine = too many messages
-amphetamines increase the amount of dopamine = give paranoid behaviour similar to schizophrenia
-antipsychotic drugs block dopamine receptors
-hyperdopaminergia in the subcortex = role of high levels of dopamine in the subcortex e.g brocas area associated with speech poverty
-hypodopaminergia in the cortex = Rakic et al 2004 = role of low levels of dopamine in the pre-frontal cortex is reponsible for negative symptoms of schizophrenia
Goldman Rakic et al (2004) suggested that hypodopaminergia in the prefrontal cortex may be responsible for negative symptoms of SZ, such as speech poverty and avolition. This is because the prefrontal cortex is associated with logical thinking, so abnormally low dopamine levels in this area may impair an individual’s ability to construct grammatical sentences that are focused upon one topic (speech poverty) or the ability to make decisions about how to function in day to day living (avolition).
strengths dopamine hypothesis
-practical application = antipsychotic drugs (Tausher et al 2014) –> important role of dopamine for schizophrenia. Genes that increase dopamine = Riker et al
limitations dopamine hypothesis
-mixed evidence for dopamine hypothesis –> increase dopamine = schizophrenic like symptoms but not the disorder (Curran et al 2004)
-correlation doesn’t mean causation