Schizophrenia

Question	Answer
What is the definition of 'schizophrenia'?	It is a serious psychological disorder suffered by about 1% of the population.
At what age does schizophrenia commonly occur and what are the incidence rates for different genders?	• Schizophrenia commonly occurs between 15-45 years old. • There is an equal incidence rate between males and females but males often show onset at an earlier age.
What are the two major systems for the classification of schizophrenia?	• International Classification of Disease (ICD) • Diagnostic and Statistical Manual (DSM)
Which of these systems is more commonly used?	The Diagnostic and Statistical Manual. This states that symptoms need to be present for at least one month and at least one must be a 'positive symptom'.
How many groups can symptoms be split into?	Two - Positive and Negative.
What are 'positive symptoms' and give two examples?	Additional experiences beyond those of ordinary existence. This includes: • Hallucinations. • Delusions.
Define 'hallucinations'.	• Unusual sensory experiences, may be related to the environment. • Can be related to any of the senses.
Describe examples of 'hallucinations'	• Hearing critical commentary on the sufferer • Seeing distorted faces of people not there.
Define 'delusions'.	• Irrational beliefs of various forms. • Can concern body (e.g. believing to be under external control) • Behaviour as a result may seem bizarre to others but make sense to sufferer.
Describe examples of 'delusions'.	• Believing to be important historical, political or religious figure. • Believing to be persecuted. • Believing to have superpowers.
What are 'negative symptoms' and give four examples.	Irrational beliefs, taking place in a variety of forms. This includes: • Speech Poverty. • Avolition. • Disturbance of Effect. • Psychomotor Disturbances.
Define 'speech poverty'.	• Excessively brief replies to questions with minimal elaboration. • Can be accompanied by a delay in verbal responses or wandering off from the point, inventing new words and phrases, stopping mid-sentence and muddling words (referred to as Thought Processing Disorder)
What do the different classification systems include 'Thought Process Disorder' as?	• The ICD includes this as part as Speech Poverty symptom. • The DSM states that it is a separate symptom from Speech Poverty and classifies it as a positive symptom.
What is 'avolition'?	The inability to make decisions, feeling unenthusiastic with no energy, lose interest in personal hygiene lack sociability and affection.
Define 'disturbance of effect'?	To appear uncaring, display inappropriate emotional responses (such as laughing at bad news or displaying sudden mood swings).
Define 'psychomotor disturbances'.	Frozen 'statue-like' poses, tics, twitches and repetitive behaviour such as pacing.
What two symptoms must be included in any description of negative symptoms?	• Speech poverty. • Avolition.
Where was the classification system DSM-5 produced?	The USA. Extra: DSM is the most commonly used classification system.
Who was the ICD-10 produced by?	The World Health Organisation.
What should these classification systems lead to?	A diagnosis that is: • Reliable. • Valid.
Issues that may affect accuracy of diagnosis are...	• Co-morbidity. • Culture Bias. • Gender Bias. • Symptom Overlap.
Describe in depth, what is reliability and how it applies to the diagnosis of schizophrenia.	Reliability concerns consistency of symptom measurements. Can affect diagnosis in two ways: • Test-retest reliability. • Inter-rater reliability.
Define test-retest reliability.	A clinician makes the same diagnosis on separate occasions from the same information.
Define inter-rater reliability.	Different clinicians make identical, independent diagnoses of the same patient.
Provide evidence for the importance of reliability in the diagnosis of schizophrenia which shows that the classification systems have become more valid over time.	• Beck (1952) found 54% concordance (similarity rate) between experienced practitioners' diagnoses of 153 patients. • Rosenhan agreed in own study using confederates. • Later research=change - Soderberg (2005) found 81% concordance rate using DSM classification.
Give a description of validity.	Concerns the accuracy of diagnosis. There are several ways in which validity can be assessed: • Reliability. • Predictive validity. • Descriptive validity. • Aetiological validity.
What is reliability?	A valid diagnosis must first be reliable, though reliability in itself does not guarantee validity.
Define predictive validity.	If diagnosis leads to successful treatment, then it is seen as valid.
What is descriptive validity?	Patients with schizophrenia should differ in symptoms from patients with other disorders.
Define aetiological validity.	To be valid, all schizophrenia patients should have the same cause for the disorder.
Which studies provide evidence for the theory surrounding the importance of validity in the diagnosis of schizophrenia?	• Jager (2003) found that it's possible to use ICD to distinguish 951 cases of schizophrenia from 521 other psychotic disorders. • Hollis (2000) reports that matching patients diagnosed with schizophrenia to DSM criteria had strong correlation. • Mason (1997) tested four different classification systems to predict outcome of the disorder over the a 13 year period in 99 schizophrenia patients.
What is co-morbidity?	• One or more additional diseases/disorders occur simultaneously with schizophrenia. • Can create problems with reliability of diagnosis as may be confusion over which disorder is being diagnosed. • People with schizophrenia often also suffer with forms of depression at the same time.
Provide 2 pieces of research evidence suggesting the impact of co-morbidity.	• Sim (2006) reported 32% 142 hospitalised schizophrenia patients had additional mental disorder. Illustrates problem in achieving reliable and valid diagnosis. • Goldman (1999) reported 50% 'schizophrenics' had co-morbid medical condition, e.g. substance abuse.
What is culture bias within schizophrenia?	• Tendency to over-diagnose other cultures of suffering with schizophrenia. • In Britain, those of African-Caribbean descent more likely than white people to be diagnosed with schizophrenia. • Also more likely to be compulsorily confined/sectioned in 'closed'/secure hospitals.
Provide 2 pieces of research that support the lack of validity in diagnosis as a result of culture bias.	• Cochrane (1977) reported incidence of schizophrenia in West Indies and Britain to be similar (around 1%) but those of African-Caribbean origin 7 times more likely to be diagnosed when living in Britain. • Whaley (2004), main reason for incidence of schizophrenia amongst black Americans (2.1%) compared to white (1.4%) is cultural bias as ethnic differences in symptom expression are overlooked/misinterpreted.
What is the relevance of gender bias in schizophrenia.	• Some argue because clinicians are mainly men, they apply criteria differently to each gender. • Therefore, diagnosis may be invalid and unreliable. • Clinicians also tended to ignore different pre-disposing factors in males and females and different vulnerability levels at different points of life.
Provide 2 pieces of research evidence suggesting the effect of gender bias on the diagnosis of schizophrenia.	• Lewin (1984) found clearer diagnostic criteria lowered number of female sufferers, suggesting gender bias in original diagnosis. • Reichler-Rossler & Hafner (2000), males have more negative than positive symptoms and this is overlooked in diagnosis.
What is the effect of symptom overlap in the diagnosis of schizophrenia?	• Symptoms are similar to those of other disorders. • Makes it difficult for clinicians to decide which disorder is the correct diagnosis. • Example - bipolar disorder, where depression and hallucinations are common symptom. • Further example - cocaine addiction.
Suggest 2 pieces of research evidence that support the theory of symptom overlap.	• Serper (1999), assessed patients with co-morbid schizophrenia and cocaine abuse, cocaine addiction alone and schizophrenia alone.Although considerable overlap in symptoms, possible to make accurate diagnosis. • Ophoff (2011) assessed genetic material from 50,000 participants, found 7 gene locations on genome associated with schizophrenia, 3 also associated with bipolar disorder, suggesting genetic overlap.
A biological explanation for schizophrenia is genetics, elaborate.	• Suggests schizophrenia transmitted through genes passed on throughout family. • Believed it is number of genes which increase individuals chance in developing disorder. • Twin, adoption & family studies and gene mapping are two methods of studying genetic inheritance of schizophrenia.
What is gene mapping?	• New technique. • Looks for genetic material commonly found in sufferers. • Has identified number of genes seeming to have influence.
What is a key study which explores genetic inheritance of schizophrenia by conducting an experiment on twins?	• Gottesman and Shields (1966), studied concordance rate of MZ and DZ twins. • Psychiatric hospital patient records 1948-1964, 57 pairs of twins. • 4 categories, separated based of patient notes, semi-structured interviews, parents and personality and thinking tests. • Groups; both schizophrenia & hospitalised; both hospitalised 1 schizophrenia, other related disorder; 1 schizophrenia, other different disorder; 1 schizophrenia, other clinically normal.
What were the findings of this study?	• Concordance for categories 1 and 2 combined = 54% MZ and 18% DZ. • Including category 3 = 79% MZ and 45% DZ. • Concordance in females higher = 77% whereas males 49%. • Shows strong genetic component but identifies not only factor otherwise MZ would be 100%.
What does 'MZ' and 'DZ' represent?	• MZ = Monozygotic/identical (1 zygote) twins. • DZ = Dizygotic/non-identical (2 zygotes) twins.
What is 'concordance rate'?	Similarity - e.g. in this case, between the twins, how likely would a twin be to develop schizophrenia if their sibling already has the disorder.
What is the purpose of adoption studies?	• Able to isolate effects of biology and environment. • May be able to see the effects of one twin with one type of family and the other twin with a completely different type.
Give an example of research with an adoption study.	• Kety et al (1968). • Copenhagen records of 5483 adopted children, 33 with schizophrenia. • Found concordance for disorder was higher between them and biological relatives rather than adopted. • If adopted parent developed disorder, this did not cause adopted child to develop disorder when compared to matched controls.
What are family studies?	• Provide evidence for genetic explanation. • Focus on immediate family not just on studies of twins.
Suggest a family study that is relevant.	• Parmas et al (1993). • Longitudinal family study. • 16% children whose mothers had schizophrenia developed disorder. • Compared 2% children whose mothers who did not have schizophrenia. • This suggests genetic link.
Evaluate the genetic explanation to schizophrenia (5 points, all negative).	- Sorri et al (2004). Longitudinal study, 21 years, Finnish adoptees, biological mothers had schizophrenia compared with those who didn't. Took into account family rearing styles in adoptive families. Adoptees with higher genetic chance of developing more sensitive to non-healthy rearing patterns. Nature/nurture, both factors. - Studies never found 100% concordance for MZ twins. Disorder cannot be solely genetic (only risk factor). Evidence from study of MZ twins is confusing, concordance rates vary between studies (not reproducible). - Suggested family similarities could be linked to common rearing patterns as opposed to biological makeup. Some explanations suggest certain home environment more likely to cause or prolong disorder. - Joseph (2004) MZ and DZ may not have equivalent upbringings and may not be comparable. Widely accepted that MZ treated more similarly and have more similar experiences as well as identity confusion. - Adoption studies assume that adoptees have not been selectively placed. Joseph (2004) argues parents may be informed to child's genetic background.
What is the dopamine hypothesis?	• Biological explanation for schizophrenia. • Dopamine increases rate of firing neurons during synapse when neurotransmitters help transmit signals across gaps between nerve fibres, enhancing communication. • Snyder (1976) suggested release of too much dopamine leads to schizophrenia. • Theory developed observation dopamine-releasing drugs, L-dopa, producing similar symptoms but in healthy patients. • Likely genetic factors linked to faulty dopaminergic systems.
Who updated the dopamine hypothesis?	• Davies et al (1991)

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	Created by Emma Chell over 7 years ago