Psychology-Schizophrenia Flashcards
What is schizophrenia?
A type of psychosis, a severe mental disorder in which thoughts and emotions are so impaired that contact is lost with external reality
How common is schizophrenia?
It is the most common psychotic disorder and affects about 1% of the population at some point in their life
When is schizophrenia most often diagnosed?
Between ages 15 and 35
What is the gender difference in schizophrenia?
Men and women are affected equally
What are two resources often used to diagnose schizophrenia?
The ICD 10 and the DSM V
What is the ICD 10?
The international classification of diseases version 10 is mostly used in Europe
What is the DSM V?
The diagnostic and statistical manual of psychiatric disorders version 5 is most often used in USA. It’s a classification and description of over 200 mental disorders, grouped in terms of their common features
How does the DSM V diagnose schizophrenia?
Must meet criterion A (two or more positive symptoms unless they are bizarre or hallucinations are a running commentary or in conversation with multiple voices), criterion B (social/occupational dysfunction), and criterion C (continuous signs of disturbance persists for at least 6 months)
What are the two types of symptoms?
Positive (an excess or distortion of normal functions), and negative (a diminution or loss of normal functioning)
What are the positive symptoms of schizophrenia?
Hallucinations, delusions, disorganised speech, and grossly disorganised or catatonic behaviour
What are hallucinations?
Distortions or exaggerations of perception in any of the senses, mostly auditory hallucinations, but can be visual, olfactory or tactile
What are delusions?
Firmly held bizarre beliefs that are caused by distortions of reasoning or misinterpretations of perceptions or experiences. These can sometimes be paranoid delusions or delusions of grandeur or delusions of reference (events in environment appear to be directly related to them)
What is disorganised speech?
The result of abnormal thought processes, that then shows up in speech
What is grossly disorganised or catatonic behaviour
Includes inability or motivation to initiate or complete a task leading to difficulty in daily life. Catatonic behaviours are characterised by a reduced reaction to the immediate environment, rigid postures, or aimless motor activity
How common are negative symptoms?
About one in three schizophrenia patients suffer from significant negative symptoms (Mäkinen et al)
What are negative symptoms also known as?
Deficit syndrome characterised by the presence of at least two negative symptoms for at least 12 months. These often lead to more pronounced cognitive deficits and poorer outcomes (Milev et al) and they often respond poorly to antipsychotic treatment
What are the negative symptoms of schizophrenia?
Speech poverty, avolition, affective flattening and anhedonia
What is speech poverty?
The lessening of speech fluency and productivity, which reflects slowing or blocked thoughts. Often have difficulty in spontaneously producing words at a time. Also maybe less complex syntax eg fewer clauses
What is avolition?
The reduction, difficulty or inability to initiate and persist in goal-directed behaviour, often mistaken for apparent disinterest
What is affective flattening?
Reduction in the range and intensity of emotional expression, including facial expression, voice tone, eye contact and body language
What is anhedonia?
Loss of interest or pleasure in all or almost all activities, or lack or a lack of reactivity to normally pleasurable stimuli. It can be pervasive, physical or social
What is reliability?
Reliability means consistency therefore in relation to diagnosis of schizophrenia, we should see consistency in diagnosis
What is validity?
Validity refers to whether an observed effect is a genuine one, so in relation to diagnosis of schizophrenia, it it a true diagnosis?
What are the relevant types of reliability?
Test-re-test reliability, inter-rater reliability (ICD/DSM should raise this)
What are the relevant types of validity?
Symptom overlap (many disorders share symptoms which could lead to the wrong diagnosis), co-morbidity (where a person has more than one disorder it can make it harder to diagnose), and predictive validity (a diagnosis should allow psychiatrists to give a clear prognosis for all sufferers that are diagnosed with the same type of schizophrenia)
What are the relevant types of bias?
Cultural bias, gender bias (critics of the DSM say its categories are biased towards diagnosing one gender more than the other), and confirmation bias (sometimes psychiatrists have been criticised for trying to ‘find a diagnosis’ rather that give a true diagnosis or non diagnosis based on symptoms)
What were the research findings in Copeland, and what problem is highlighted?
Compared a group of American and a group of British Psychiatrists diagnosing the same patients, only 2% of British psychiatrists diagnosed schizophrenia compared to 69% of America psychiatrists. This highlights lack of inter rater reliability and culture bias
What problem is highlighted where different psychiatrists have used the DSM and found correlation coefficients as low as 0.11 between psychiatrists diagnosing schizophrenia?
Lack of inter rater reliability
What problem is highlighted by the used of ‘bizarre’ as a determinant for whether one or two symptoms are needed, leading to a concordance rate of 0.4 in senior psychologists?
Lack of inter rater reliability
What is an example of co-morbidity in diagnosing schizophrenia?
Research shows many schizophrenic patients have medical issues such as asthma, diabetes and hypertension. Other research shows 50% of schizophrenics have another disorder, mostly depression, substance abuse or anxiety. Also high rates of OCD in schizophrenic patients
What is the problem highlighted by the DSM being androcentric?
Gender bias as what is classed as mentally healthy for an adult is actually healthy ‘male’ behaviour
What does Rosenhan’s study ‘being sane in insane places’ illustrate?
Lack of reliability in diagnosis, and confirmation bias
What are the evaluation points for validity?
Research support for gender bias (Loring and Powell where psychiatrists judged patients labelled as males (56% diagnosed), females (20%) or not labelled (56% diagnosed)). The consequences of co-morbidity and differences in prognosis (predictive validity)
What are the evaluation points for reliability?
Lack of inter-rater reliability (Copeland), unreliable symptoms (use of ‘bizarre’ and senior psychiatrists) and cultural differences in the diagnosis of schizophrenia (America vs Britain)
What are the three kinds of biological explanations for schizophrenia?
Genetics, bio-chemistry and a link between the flu virus during pregnancy to the development of schizophrenia
What family members share 100% of their genes?
Identical twins
What family members share 50% of their genes?
Non-identical twins, brothers and sisters, parents and children
What family members share 25% of their genes?
Grandparents and grandchild
What does the genetic explanation suggest about schizophrenia?
That it is hereditary as it tends to run in families and you are more likely to develop it if you have a close family member with schizophrenia, however no single ‘schizophrenic gene’ has been identified-it is different combinations of genes that makes someone more prone to developing the disorder
What types of studies are used to investigate the role of genetics in schizophrenia?
Family studies, twin studies and adoption studies
Explain family studies into schizophrenia
They look at concordance rates of features with different family members. Those more closely related to someone with schizophrenia are more likely to develop it. Eg Gottesman found that having two schizophrenic parents had a higher concordance rate than someone with one schizophrenic parent
Explain twin studies into schizophrenia
Look at difference in concordance rates between MZ and DZ twins and those raised apart or together. If the biological explanation was completely correct that MZ twins should have almost 100% concordance rate. Joseph found that concordance rates were dramatically higher in monozygotic twins
Explain adoption studies into schizophrenia?
Look at the concordance rates between biological parents and children, and adopted children and parents. Tienari et al found concordance rate higher between adopted children with biologiscal parents with schizophrenia, than those without schizophrenic biological parents
What are the evaluation points for genetic factors?
Common rearing patterns may explain family similarities instead of heredity, MZ twins encounter more similar environments which is why there is a difference between MZ and DZ twins (Joseph), In adoption studies if the adoptive parents know the child’s biological parents have schizophrenia then they may look out for signs that aren’t actually there to show the child is schizophrenic, leading to a high concordance rate
What is the biochemical explanation of schizophrenia?
Neurons transmit messages in the form of neurotransmitters which cross the synapse to another neuron. Once the neurotransmitter is released, it is either locked into the receptor site or broken down or reabsorbed (reuptake). The key neurotransmitter in schizophrenia is dopamine
What is the dopamine hypothesis?
In a schizophrenic brain, there is an excess of dopamine activity which is associated with positive symptoms. Neurons transmit dopamine fire too easily, and neurones receiving dopamine have too many receptors
What drugs can cause schizophrenic symptoms?
Amphetamines as these increase dopamine. Also L-Dopa is a drug prescribed for Parkinson’s disease which is linked to low levels of dopamine however patients that use this medication have reported schizophrenic symptoms such as hallucinations. Symptoms usually go after stopping the medications
What drugs decrease schizophrenic symptoms?
Anti-psychotics because they reduce dopamine and so are effective in treating positive symptoms. This strengthens the case for the importance of dopamine in this disorder
What is the updated dopamine hypothesis?
Davis and Kahn propsed that positive symptoms of schizophrenia are caused by an excess of dopamine in subcortical areas of the brain, particularly in the mesolimbic pathway. The negative and cognitive symptoms are thought to arise from a deficit of dopamine in areas of the prefrontal cortex (mesocortical pathway)
Where does evidence for the Dopamine Hypothesis come from?
Leucht et al’s meta-analysis of studies that compared effectiveness of psychotic in reducing schizophrenic symptoms to a placebo. The found that all the drugs tested were significantly more effective than the placebo
What do critics of the dopamine hypothesis argue?
That the effects of adjusting dopamine have been exaggerated. One way this is shown is through negative or inconclusive results of dopamine concentration in post-mortem brain tissue research. Mocrieff points out that confounding sources of dopamine such as stress and smoking are rarely considered. Lack of current evidence of the dopamine hypothesis. Stimulant drugs can also induce schizophrenic episodes (affect many neurotransmitters other than dopamine)
What are the evidence points for the dopamine hypothesis?
Evidence from treatment (Leucht et al), inconclusive supporting evidence (Moncrieff), and challenges to the dopamine hypothesis (Noll-strong evidence for both versions of the hypothesis, but anti-psychotic drugs don’t work on 1/3 of patients and some people experience symptoms with normal dopamine levels, suggesting other neurotransmitter systems produce positive symptoms)
What are the psychological explanations for schizophrenia?
Family dysfunction (double blind theory and expressed emotion) and cognitive explanations
What are family dysfunction explanations?
Explanations for schizophrenia that focus on the idea that is is caused by abnormal patterns or communication within the family
What is double blind theory based on?
The idea that schizophrenics have regularly received contradictory messages from parents as a child, for example, the verbal message may be of affection but the non verbal message may be of animosity or disgust to the child
How do these contradictory messages affect the child?
They don’t know how to respond to the parent, they are unsure whether to respond to the verbal or behavioural cue, they are unaware of which cue is the ‘real’ one
How does double blind theory explain the development of schizophrenia from contradictory messages?
The child doesn’t know how to respond to the parent. Such contradictions prevent the child from developing a coherent construction of reality-too many contradictory messages do not allow sense to be made. In time, this manifests itself as schizophrenic symptoms such as withdrawal from social situations and a loss of contact with reality
How does Tienari et al’s adoption study support the role of dysfunctional family life?
Those who developed schizophrenia were the ones that’s adopted family was rated as disturbed. Supports family dysfunction as an explanation for schizophrenia over biological/genetic explanations
How does Berger’s research support double blind theory?
Found that schizophrenic individuals reported having received more contradictory messages from parents than non-schizophrenia individuals suggesting that double blind messages do play a role in the development of schizophrenia