Schizophrenia Flashcards
what is Diagnosis and classification
Classification is a cluster of symptoms that occur together classifying as one disorder. Diagnosis is possible by identifying the symptoms
2 systems of classification:
- ICD-10 by the world health organisation
(previously had subclasses of schizophrenia e.g. paranoid that got dropped bc symptoms would change over time)
- DSM-5 by the American psychiatric association
Positive symptoms
- Symptoms that are additional (beyond ordinary existence)
Hallucinations: unusual sensory experiences some related to the environment some not. can be experienced by any sense
Delusions: also called paranoia, irrational belief. take a range of forms including being a famous historical figure, being watched by the government, being under external control
Negative symptoms
- symptoms that involve the loss of usual ability and experience
Speech poverty: characterised by changes in speech patter, reduction in amount and quality of speech, sometimes a delay in verbal response and disorganised speech (it is incoherent or the speaker changes topic mid sentence)
Avolition: sometimes called apathy. Finding it difficult to keep up with goal directed activity. Andreasen’s 3 signs of avolition: - poor hygiene and grooming
- lack of persistence in work/ education
- lack of energy
Evaluate Issues in diagnosis and classification
+ Good reliability
> Osorio et al reported excellent reliability for diagnosis of schizophrenia in 180 individuals using DSM-5.
> Pairs of interviewers had +9.7 inter-rater reliability and +9.2 test-retest reliability
- Low Validity
Cheniaux et al had two psychiatrists independently diagnose the same 100 clients using DSM-4 and ICD-10
> DSM 4, 39 were diagnosed, ICD-10: 68 were diagnosed
CA: Osorio’s research shows the issue is with the validity is good providing it takes place within a single system
- Co-morbidity
> schizophrenia almost always appears with other conditions e.g. depression, substance abuse suggesting it may not be its own condition
- Gender bias
> women may be underdiagnosed because they have better support systems so can better mask the symptoms (cotton et al)
- Culture bias
> hearing voices can mean different things in different cultures e.g. in Haiti it can mean communications from ancestors
> British people of African-Caribbean origin are up to 9x more likely to get a diagnosis as white British people
- Symptom overlap
> there is considerable overlap of symptoms with other conditions like Bipolar disorder making them difficult to distinguish
Biological explanations of Schizophrenia: genetic bases
Family studies
- risk of schizophrenia increases with genetic similarity to a relative with the disorder
- Gottesman: large scale family study. Someone with an aunt w schizophrenia has a 2% chance of developing it, identical twin: 48%
Candidate Gene
- early research looked for a single responsible gene, but there appear to be many involved (polygenic)
- most likely to be genes coding for neurotransmitters incl dopamine
- Ripke et al combined all previous data and found 108 genetic variations linked to risk of Szp
- different combos = szp
Role of mutation
- Genetic origin in absence of family history may be because of a mutation in parental DNA because of an environmental effect
- Brown et al: positive correlation between paternal age and risk of szp
Biological explanations of Schizophrenia: evaluate genetic bases
+ Research support
> Gottesman
> Tienari et al: even in adopted families, risk of schizophrenia is higher if Bio parents have it
> Hilker et al: concordance rates of 33% for identical and 7% for non identical twins
- Evidence for environmental factors
- Morgan et al: increased risk due to birth complications
- Di Forti et al inc risk due to smoking TBC rich cannabis as a teen
Morkved et al 67% of people with schizophrenia had childhood trauma as opposed to 38% of a matched group who didn’t
Biological explanations of Schizophrenia: Neural correlates
- we don’t know what causes Szp symptoms on a bio level but research has found neural correlates
OG dopamine hypothesis - Drugs (antipsychotics) used to treat szp caused symptoms similar to people with Parkinson’s disease (related to low DA) so schizophrenia is a symptom of high DA
- Excess of DA receptors in Broca’s area may explain speech poverty and Auditory hallucinations
Updated Dopamine Hypothesis - Davis et al: there is also abnormally low DA in the brains cortex explaining some negative symptoms
- Abnormal dopamine levels caused by genetic variations and early psychological and physical stress
Biological explanations of Schizophrenia: evaluate Neural correlates
+ research support
> Amphetamines increase DA and worsen symptoms in people with Szp and induce them in people without (Curran et al)
> Antipsychotics reducing DA activity reduce intensity of symptoms (Tauscher et al)
> some candidate genes act of production of DA or DA receptors
- Glutamate
> Post mortem and brain scanning studies have found raised levels of the neurotransmitter glutamate in people with szp
> several candidate genes are believed to be involved in its production or processing
Psychological explanations of schizophrenia: Family dysfunction
Schizophrenogenic mother Fromm-Reichmann noticed many of her patients had a ‘cold, rejecting and controlling’ mother creating an environment of tension and secrecy leading to later paranoid dilutions.
** Double bind theory** Bateson et al: the child finds themself in a situation where fear they are doing something wrong but get mixed messages about what it is and cant ask. When they ‘do something wrong’ they are punished with withdrawal of love leaving them with an understanding of the world being confusing and dangerous causing paranoid delusions and disorganised thinking.
Expressed emotion the level of negative emotion expressed towards a person with schizophrenia by their carer. contains several elements: verbal criticism occompanied by violence (sometimes), hostility anger and rejection, and emotional overinvolvement/ needless self sacrafice. These elements cause serious stress and cause relapse or trigger it in vulnerable people
Psychological explanations of schizophrenia: Evaluate Family dysfunction
+ research support
Read et al: adults with schizophrenia were disproportionately more likely to be insecurely attached and 69% of women and 59% men w. schizophrenia have a history of physical and/or sexual abuse
> Morkved et al most adults with schizophrenia report at least one childhood trauma usually abuse
- lack of support
> no support for the importance of traditional family based theories like double bind of the schizophrenogenic mother both based on informal assessment and observation not systematic evidence
Psychological explanations of schizophrenia: Cognitive explanations
Dysfunctional thinking cognitive explanation for phenomenon’s focusing on mental process. can be seen in many symptoms (Simon et al):
- reduced processing in the ventral striatum associated w. negative symptoms
- reduced processing in temporal and Cingulate gyri associated with hallucinations
Metarepresentation dysfunction Frith et al: cognitive ability to reflect on our thoughts and behaviour and interpret others actions. dysfunctions prevents us from recognising our thoughts and actions as our own explaining hallucinations and delusions like thought insertion
Central control dysfunction Frith et al: issues with the ability to supress automatic responses while performing deliberate actions e.g. speech poverty could be bc of the inability to supress automatic thoughts and speech triggered by other thoughts.
Psychological explanations of schizophrenia: Evaluate Cognitive explanations
+ Research support
> John Stirling compared the performance on a range of tasks including Stroop on 30 people with and 30 people without SZP
> people with Szp took longer to state the ink colour of words suggesting slower cognitive processing
- Proximal explanation
> explains current symptoms but not cause
> partial explanation
Bio therapy: Typical antipsychotics
Dopamine antagonists typical antipsychotics like chlorpromazine work by reducing the action of a neurotransmitter (in this case blocking dopamine receptors. Dopamine levels initially increase then production is reduced which should reduce symptoms.
Sedation effect it is not fully understood but is believed that they also work on histamine receptors. Chlorpromazine is therefore used to calm individuals with szp or other conditions and anxious hospital patients. Given in a syrup when used for this purpose
Bio therapy: Atypical antipsychotics
- made to minimise side effects.
Clozapine Found to be more effective than typical antipsychotics and was used when other treatments failed. potentially fatal side effects so not available as an injection, lower dose and regular blood tests for users.
Binds to dopamine receptors as well as seritonin and glutamate. Believed to improve mood and cognitive function and reduce depression and anxiety so given to individuals considered to be at high risk of suicide.
** risperidone** more recent. developed to be a less dangerous alternative to clozapine. believed to bind to dopamine and serotonin receptors more strongly than clozapine so is more effective in a smaller dose which there is some evidence for resulting in fewer side effects
Bio therapy: Evaluate
+ evidence of effectiveness.
> Thornley et al: reviewed studies comparing chlorpromazine to controls and found it was associated with better functioning and reduced symptoms.
>Meltzer concluded that clozapine is more effective than other antipsychotics and effective in 30-50% of cases where typical antipsychotics have failed
CA Healy suggested flaws with evidence e.g. most studies are only for short term effects, successful trials have been published several times exaggerating success, cant tell if it actually reduces psychosis or just calms patients.
- side effects
> Typical antipsychotics can cause dizziness, weight gain, itchy skin. Long term use can cause tardive dyskinesia which causes involuntary facial movements
> Can cause NMS which may be fatal
- understanding
> our understanding of how they work is tied up with the OG dopamine hypothesis which we now know to be an oversimplification.
> some antipsychotics may not be the best treatment.
Psychological therapy: cognitive behavioural therapy
can help with making sense of irrational delusions. Understanding delusions as a malfunction of the speech centre of their brain or voices are extensions of ordinary thinking in words can make them less scary. This is normalisation.
Delusions can be challenged through reality testing where patient and therapist together examine the likelihood of a delusion
in more severe/ resistant cases, it can still reduce anxiety and depression.
Psychological therapy: evaluate CBT
+ Evidence for effectiveness
> Jauhar et al: reviewed 34 studies and concluded their is evidence for small gut significant effects on positive and negative symptoms of schizophrenia
- quality of evidence
> Thomas pointed out different studies involved use of different CBT techniques and people with different combinations of symptoms
Psychological therapy: family therapy
- improves quality of communication and interaction between family members
Pharoah et al range of strategies to improve functioning
reduces negative emotions
aims to reduce levels of expressed emotion like anger and guilt causing stress and therefore relapse.
improves family ability to help encourages family members to form therapeutic alliances where they agree on the aims of therapy and ensure balance between caring for a schizophrenic family member and maintaining their own lives.
Psychological therapy: evaluate family therapy
+ evidence of effectiveness
> McFarlane reviewed studies and concluded family therapy was one of the most consistently effective treatments reducing relapse typically by 50-60%
> particularly effective as mental health starts to decline
+benefit to the whole fam
> benefits the family that provide the bulk of the care lessening the impact on the rest of the family and increasing their ability to support the schizophrenic family member.
