SCHIZOPHRENIA Flashcards
form of psychosis
severe mental disorder where thoughts and emotions are significantly impaired and there is loss of touch with reality
culturally universal
1% of world population
seen in all cultures - not due to culture
more commonly diagnosed in urban than rural areas
* Slightly more commonly diagnosed in men than in women.
Onset for men tends to be between 15-24 years.
Onset for women is more prevalent between 25-34 years.
positive symptoms
- Behaviours not generally seen in ‘normal’ people.
Something extra
A behaviour or reaction that you didn’t have before.
hallucinations
delusions
hallucinations
- Bizarre, unreal perceptions of the environment that other people don’t experience.
- Usually auditory (hearing voices), but can be visual (seeing things), olfactory (smelling things) or tactile (e.g. feeling bugs crawling).
- Many report hearing a voice or several voices telling them to do something or commenting on their behaviour.
delusions
- Bizarre beliefs that seem real but aren’t.
- Can be paranoid in nature.
- Often involves a belief that the person is being followed or spied upon by someone.
- May also involve inflated beliefs about the person’s power and importance (delusions of grandeur) e.g. may believe they are famous or have special powers.
- May also experience delusions of references, where events in the environment appear directly related to them.
negative symptoms
- Associated with disrupted to normal emotions and behaviour.
Reflect a reduction or loss of normal function.
avolition
speech poverty (alogia)
disorganised speech
flattened/blunted affect
anhedonia
avolition
- Reduction in interests and desires and inability to initiate and persist in goal-oriented behaviour.
- Distinct from poor social function or disinterest.
- Reduction in self-initiated involvement in activities available to the patient.
speech poverty (alogia)
- Lessening of speech fluency and productivity, thought to reflect slowing or blocked thoughts.
- Fewer words in a given time on a verbal fluency task – difficulty of spontaneously producing them.
- Reflected in less complex syntax e.g. fewer clauses, shorter utterances.
- Associated with long illness and earlier onset of the illness.
disorganised speech
- Result of abnormal thought processes, where the individual has problems organising thoughts.
- May slip from one topic to another (derailment) even midsentence.
- Speech may be incoherent and sound like gibberish.
flattened / blunted affect
- Reduction in range and intensity of emotional expression, including facial expression, voice tone, eye contact and body language.
- Individuals show fewer body and facial movements and less co-verbal behaviour.
- Deficit in prosody (paralinguistic features) that provide extra information not explicitly contained in a sentence and gives cues to the listener as to emotional or attitudinal content and turn-taking.
anhedonia
- Loss of interest and pleasure in all or almost all activities, or a lack of reactivity to normally pleasurable stimuli. May be pervasive or confined to certain aspect of experience.
- Physical anhedonia is inability to experience physical pleasures e.g. food, bodily contact.
- Social anhedonia is inability to experience pleasure from interpersonal; situations such as interacting with other people.
comorbidity
Simultaneous presence of two or more diseases or medical conditions.
May cause misdiagnoses.
symptom overlap
People diagnosed with one mental disorder simultaneously show symptoms of another psychological disorder.
May cause misdiagnoses.
diagnostic criteria
- To diagnose psychological disorders, qualified practitioners will consult classification systems / diagnostic criteria that outline symptoms required to be evidenced by patient.
- DSM-5 (Diagnostic and Statistical Manual of Psychiatric Disorders) created by American Psychiatric Association.
- ICD-11 (International Classification of Diseases) developed by World Health Organisation and is commonly used in Europe and in the rest of the world.
Suggest similar persistent symptoms
Differences in criteria – symptoms for 1 or 6 months.
Criteria lacks consistency, reducing reliability and validity of diagnoses.
reliability of diagnoses
- Reliability refers to consistency and how consistently the same diagnosis is made.
- Test-retest reliability – diagnose somebody, then repeat and compare results to check consistency.
- Inter-rater reliability – make diagnosis and ask somebody else to see if they would make same diagnosis.
Measured statistically using a Kappa score (coefficient used for qualitative analysis.
Score of 0.7 is generally deemed acceptable. - Read found that diagnosis of schizophrenia only had a 37% concordance rate when diagnoses were made on two separate occasions.
194 British and 134 US psychiatrists gave diagnoses based on a case description. 69% of US psychiatrists diagnosed schizophrenia compared to 2% of British psychiatrists.
Used test re-test. Low reliability due to 0.37 concordance rate (0.7 acceptable).
Poor inter-rater reliability – differs across countries.
validity of diagnoses
- Validity refers to accuracy.
- Correctly diagnosing schizophrenia as a distinct disorder and not misdiagnosing a different disorder.
- Descriptive validity – diagnosis is valid if symptoms differ significantly from those of other diagnosable conditions. Can therefore be considered a distinct disorder.
- Criterion validity – the extent to which using different classification symptoms produces the same diagnosis in the same patient.
- Cheniaux asked 2 psychiatrists to diagnose a hundred patients using the ICD and DSM.
One diagnosed 26/100 patients with schizophrenia using the DSM and 44/100 using the ICD. The other diagnosed 13 with the DSM and 24 using the ICD.
Suggests criteria is not valid – less diagnoses with DSM than ICD.
Challenges criterion validity as both produce different diagnoses. Cannot accurately diagnose, do not know that schizophrenia is distinct from other disorders. Lacks descriptive validity.
Rosenhan aims
- To test the hypothesis that psychiatrists cannot reliably tell the difference between people who are sane and those who are insane.
Rosenhan procedure
- Field experiment, participant observation.
- Participants were hospital staff in 12 hospitals.
- 8 sane people tried to gain admission to hospitals. Complained that they had been hearing voices, which was of the same sex as themselves, unfamiliar and unclear. Gave false name and job but other details were true.
- After admission, stopped simulating abnormality, took part in activities and conversations as they would ordinarily. They said they felt fine and no longer had symptoms. Told they could leave by convincing staff they were sane.
- None were detected and all but one were admitted with a diagnosis of schizophrenia and were eventually discharged with ‘schizophrenia with remission’. Normal behaviours were seen as aspects of supposed illness.
- In second study, staff were told that a pseudo-patient would be admitted and asked psychiatrists to rate every new patient on a 10-point scale for the likelihood of them being a pseudo-patient.
Rosenhan results
- Psychiatrists cannot reliably tell the difference between people who are sane and those who are insane.
- Main experiment illustrated a failure to detect sanity and secondary study demonstrated a failure to detect insanity.
- Suggests that psychiatric labels stick and everything a patient does is interpreted in accordance with the diagnostic label once it has been applied.
- Suggests that diagnoses may lack reliability and that misdiagnoses are common.
- Psychiatrists were not making accurate diagnoses – even though only had one symptom, they were diagnosed with schizophrenia. Should not be enough to make any diagnosis.
- Diagnoses were consistent – all pseudo-patients who complained of symptoms were misdiagnosed – suggests reliability but not valid.
comorbidity
- Presence of multiple disorders existing at the same time.
- Schizophrenia is commonly comorbid with depression, PTSD, OCD, and substance abuse.
- Buckley reported that an estimated 50% of schizophrenia patients had co-morbid depression, 29% had PTSD and 23% OCD. 47% had co-morbid substance abuse.
- Reduces descriptive validity – do not know whether we are actually looking at schizophrenia and a comorbid disorder, rather than a completely separate disorder that encompasses symptoms from both diagnosable disorders.
- Reduces reliability (test-retest / inter-observer) – if a person exhibits two different disorders at the same time, this could impact diagnoses at different points or between psychiatrists depending on which symptoms of which disorder are more prevalent at each point of diagnosis.
- Implications (affecting treatment and prognosis) – practitioners cannot know which treatment is best if diagnosis is complicated by the presence of multiple disorders.
More likely to be adverse health outcomes, as one may go untreated in favour of the other being treated, possibly due to the avoidance of interactions between differing treatments.
symptom overlap
- Where symptoms used in the diagnosis of one disorder are also present as part of the diagnostic criteria for a different disorder.
- Schizophrenia overlaps with bipolar – both share positive symptoms like delusions and negative symptoms like avolition.
- Ophoff assessed genetic material from 50,000 participants to find that of 7 gene locations on the genome associated with schizophrenia, 3 were also associated with bipolar disorder, suggesting a genetic overlap.
- Also overlaps with cocaine intoxication and dissociative identity disorder (DID).
- Reduces descriptive validity – hard to discern which of the possible disorders is more accurate if showing symptoms of more than one disorder.
- Reduces inter-rater reliability – different psychiatrists may diagnose different disorders if symptoms can be attributed to more than one disorder.
- Ketter suggested that misdiagnosis due to symptom overlap can lead to years of delay in appropriate treatment.
- However, Serper found that despite there being considerable symptom overlap in patients with schizophrenia and cocaine abuse, it was possible to make accurate diagnoses.
gender bias
- Longenecker found that men have been diagnosed with schizophrenia more often than women.
Psychiatrists have historically been more male than female.
Diagnoses may be predominantly from a male perspective of what constitutes ‘abnormal’ behaviour (androcentrism).
Females tend to have a higher level of functioning than males which could mask symptoms and lead to underdiagnosis. E.g. males tend to experience more negative symptoms than females, leading to greater impairment of functioning. - Loring and Powell randomly selected 290 male and female psychiatrists to read two case articles of patients’ behaviour.
When participants were described as male or there was no information about their gender, 56% were diagnosed with schizophrenia.
When they were female, only 20% were diagnosed.
The gender bias did not appear to be evident amongst the female psychiatrists.
Suggests that women are better at diagnosing without bias.
Gender bias affects who is diagnosed. - Women are more likely to go underdiagnosed, and therefore face delay in treatment, which can lead to the disorder becoming more progressed.
culture bias
- Tendency to over-diagnose schizophrenia in ethnic minority cultures.
- Cochrane reported incidence of schizophrenia in the West Indies and Britain to be similar (~1%), but people of Afro-Caribbean descent were seven times more likely to be diagnosed when living in Britain.
Imposed etic - British standardised culture and social norms are used as a reference for diagnosis.
Suggests that diagnoses are not accurate or valid across cultures.
Low inter-rater reliability – psychiatrists in different cultures would not make the same diagnoses. - Rack suggested that in many cultures it is normal to see and hear recently deceased loved ones (often part of the grieving process).
Glossolalia (speaking in tongues) is a common religious practice among Pentecostal Christians, a branch common amongst ethnic minorities, including Afro-Caribbean.
Such practices are unfamiliar in Western culture and so can lead to incorrect interpretation of behaviour as being symptoms of schizophrenia when they are normal practices. - Escobar pointed out that white psychiatrists may tend to over-interpret the symptoms of black people during diagnosis.
Increased risk of over-diagnosing people from a particular culture.
Could then result in unnecessary or inappropriate treatments that can sometimes have serious negative effects.
Could be prejudice and discrimination against particular ethnicities due to a lack of understanding of cultural practices.
Risk pathologising behaviour because it is different to our own culture. - Research into schizophrenia should take a culturally relativist approach.
People should be diagnosed by psychiatrists from their own cultures so they understand the complexities of their culture.
Would lead to greater accuracy.
biological explanations
genetic explanations
neural correlates
dopamine hypothesis
drug treatments
genetic explantions
- Schizophrenia is hereditary – the trait is transmitted from parents to offspring.
- Based on concordance rates of schizophrenia between family members.
Measure of similarity between family members.
If one family member has schizophrenia, the percentage likelihood that other family members will have it too. - Twin studies and comparing concordance rates between monozygotic and dizygotic twins can be used to study genetics as a potential cause.
Monozygotic twins share 100% of DNA
Dizygotic twins share 50% of DNA – share as much DNA as regular siblings.
Adoption studies can help determine whether due to nature or nurture by twins having different shared environments.
Gottesman
- Studied 57 pairs of twins.
Concordance rate for MZ twins was 42%.
Concordance rate for DZ twins was 9%. - Carried out family studies, where concordance rates are assessed between relations of different degrees.
Suggests that schizophrenia has some genetic components.
Higher occurrence of schizophrenia when higher degrees of relatedness.
However, cannot be only factor as not 100% or 50% concordance rates.
polygenetic
- Caused by many different genes, and not one single schizophrenia-causing gene, or genes may provide a genetic vulnerability.
- Ripke found that 108 separate genetic combinations were associated with increased risk of schizophrenia.
- Accepted that schizophrenia is aetiologically heterogeneous – number of different combinations of genes can lead to it.
- E.g. COMT gene
genetic explanations strengths
practical applications
Being able to identify candidate genes that may be involved in the onset of schizophrenia could lead to clear applications.
Gene mapping – process of establishing the locations of genes on chromosomes. By following inheritance patterns, the relative positions of genes can be determined.
Can lead to benefits like monitoring and recognising symptoms earlier and having earlier diagnosis due to figuring out who has a genetic vulnerability for schizophrenia. Can receive treatment and can slow or reduce severity of symptoms. Disorder is more manageable, help improve quality of life.
Therefore the genetic explanation is useful.
However, this could be socially sensitive (research leading to prejudice, discrimination, or cause offence) as it can place responsibility and blame on the parents if their child has schizophrenia as they have given them the gene.
genetic explanations weaknesses
shared environments
Issue of shared environments could cast doubt on the role of genetics, particularly in twin studies.
Gottesman found a higher concordance rate for schizophrenia in MZ (42%) than in DZ twins (9%).
Could be due to shared environment as MZ twins are identical, so are more likely to treated the same, due to others’ perception of them being similar.
Higher degrees of relatedness, more of a shared environment (confounding variable).
Questions validity of concluding that higher concordance rates for schizophrenia are due to degree of genetic relatedness as other environmental factors could influence this.
Can’t always separate nature and nurture.
* However, there is evidence from adoption studies to support the role of genetics in schizophrenia.
Tienari found that adopted children of biological mothers with schizophrenia were more likely to develop the disorder themselves than adopted children of mothers without schizophrenia.
Reinforces the idea of inherited genetics having a larger influence on schizophrenia than environmental influences, therefore the theory is valid and credible.
genetic explanations weaknesses
concordance rates
If schizophrenia has an entirely genetic basis, we expect concordance rates to be 100% for monozygotic twins and 50% for dizygotic twins.
Should be in line with degrees of genetic relatedness if purely genetic e.g. first line family members with 50% shared genetics should have 50% concordance rates (6-17%).
Gottesman found that concordance rates for monozygotic and dizygotic twins are 48% and 17% respectively.
Suggests that genetics cannot provide a complete explanation but there must be other factors influencing the occurrence of schizophrenia.
Therefore the genetic explanation is reductionist.
May provide a genetic vulnerability to schizophrenia, but other factors may influence whether it actually occurs.
genetic explanations weaknesses
family history
Schizophrenia can occur in the absence of any family history.
Brown found a positive correlation between paternal age and risk of schizophrenia. The risk increased for 0.7% in fathers under 25 to 2% in fathers aged over 50.
A potential explanation is a mutation in parental DNA e.g. mutations are more likely with age in paternal sperm cells.
Age of parents and mutations determines presence of candidate gene.
Contradicts the suggestion of schizophrenia being hereditary but is caused by a mutation due to genes.
Limits validity of genetic explanations.
However, Brown’s research is correlational.
Cannot establish cause and effect.
neural correlates
- When structures or neurochemical processes in the brain can be associated with a particular disorder, function or characteristic.
- Assumption is that they may be implicated in originating the experience.
- Thought that specific structures and neurochemical imbalances in the brain are linked to different positive and negative symptoms.
superior temporal gyrus
- Linked with auditory hallucinations (positive)
- Allen carried out brain scans of schizophrenics and a control group while they were tasked with identifying speech as either their own or someone else’s.
Found lower activity in the part of the brain.
More mistakes were made by schizophrenics.
ventral striatum
- Linked with avolition – loss of motivation (negative)
- Juckel found lower levels of activity in this part of the brain (involved in reward anticipation) in schizophrenics compared to a control group.
Observed a negative correlation with functioning in this part of the brain and severity of symptoms.
dopamine hypothesis
hyperdopaminergia in subcortex
- High levels of dopamine activity in the central areas of the brain, notably the subcortical and limbic brain regions.
Mesolimbic pathway - Thought to be due to hyperactivity of dopamine D2 receptors in these regions.
- More associated with positive symptoms e.g. hallucinations, delusions.
- Dopamine is excitatory – increased volume, more activation and impulses sent through the brain results in higher level of activity.
- Version 1 of the theory – proposed in the 1970s after success of antipsychotic drugs treating psychosis. Carlson identified that these drugs worked via dopamine receptors.
dopamine hypothesis
hypodopaminergia in cortex
- Goldman found low levels of dopamine in the prefrontal cortex (thinking and decision making) and linked this to negative symptoms.
Mesocortical pathway - Believed to be hypofunctionality (reduced function) of dopamine D1 receptor neurotransmission in the prefrontal cortex.
- Linked to avolition – less activation results in lower level of functioning, low motivation and lack of speech production.
- Version 2 of the theory – added in 1991 by Davis who proposed regional specificity in addition to the original version.
dopamine hypothesis strengths
drug evidence
- Evidence from effects of different drugs to support the role of dopamine in psychotic symptoms associated with schizophrenia.
Curran found that dopamine agonists (drugs which increase activity) such as amphetamines produce schizophrenia-type symptoms in patients.
Supports idea of neural correlates and hyperdopaminergia as increased dopamine leads to schizophrenia symptoms.
Suggests the theory has validity.
Leads to better evidence of cause and effect – manipulating levels through drugs and observing symptoms.
However, this contradicts the idea of hypodopaminergia – suggests may depend on which dopaminergic pathway in the brain is affected.
dopamine hypothesis weaknesses
correlation
Neural correlates only show an association between areas of the brain and symptoms of schizophrenia.
Superior temporal gyrus associated with auditory hallucinations.
Cause and effect cannot be established.
Bidirectional – schizophrenia may cause changed function or neurotransmitter activity, or this may cause schizophrenia.
Therefore validity is limited.
dopamine hypothesis weaknesses
other neurotransmitters
May be other neurotransmitters involved in the onset of schizophrenia.
Glutamate alternatively linked to schizophrenia.
Acts as a brake or accelerator of dopamine so may be levels of glutamate that lead to either hyper- or hypodominergia in different brain regions.
Suggests that the dopamine hypothesis is too simplistic and we need to look at the interaction of other neurotransmitters.
Therefore our understanding of schizophrenia is still developing and is more complex than we originally thought.
dopamine hypothesis weaknesses
physiologically reductionist
Biological explanations such as neural correlates can be seen as physiologically reductionist.
Doesn’t consider cultural, societal, cognitive or behavioural influences on schizophrenia symptoms. Narrows it down to the role of neurotransmitters, structures within the brain and dopamine levels.
Focusing on biological structures and processes and neglects to consider the influence of other factors such as psychological or societal factors.
Such explanations could be oversimplifying schizophrenia by only considering its cause to be at its lowest level (neuroanatomical) and not considering how multiple factors interconnect to provide a more complex account of the disorder.
drug treatments
- Antipsychotic drugs (neuroleptics) are the most common treatment of schizophrenia.
- They work by regulating the action of the neurotransmitter dopamine in areas of the brain associated with schizophrenia.
- They reduce symptoms to allow for some degree of functioning to become possible, but they do not offer a cure.
