Lecture 13: Neuropsychiatric disorders & Psychotic disorders: Chapter 24 Flashcards
Why is schizophrenia relevant to neuropsychiatry? (2)
- Severe mental disorder
- Neruobiology and cognition is important to understanding the condition
What are the 7 disorders in schizophrenia spectrum and other psychotic disorders in the DSM?
- Schizophrenia
- Delusional disorder
- Brief Psychotic disorder
- Schizophreniform disorder
- Schizoaffective disorder
- Substance/medication induced psychotic disorder
- Psychotic diorder due to another medical condition
What percentage of people fully recovers? Which percentage of people recover partially?
Full: 25%
Partial: 50%
What is the life expectancy of people with schizophrenia and why?
Live 15-20 years shorter due to all the other symptoms –> heart disease, diabetes, suicide
Why do some people prefer psychosis spectrum instead of schizophrenia spectrum?
Schizophrenia has a lot of stigma
Describe the 3 factors in the schizophrenia spectrum
- Experiences: ideas, noticing something in your environment
- Symptoms: convinced some things are a sign and thinking about the experiences
- Disorder: you always think you’re getting signs and it interrupts your life
What is a common ground for people believing in fake news and people in psychosis?
Both are convinced something is real, despite of real convincing objective evidence.
It’s really hard to tell these people these things aren’t true and then have them accept it
What do we mean with precision medicine?
It’s important to adapt medication to the individual, since not all people respond well to e.g. antipsychotics
Which psychological disorder has the most overlap in SNP (single nucleotide polymorphisms) with schizophrenia?
Bipolar disorder –> some similar genetic predispositions
Do all schizophrenics share the same neuro-biology? Why?
No, the symptoms and behavior of schizophrenia is very heterogeneous
What is research domain criteria (RDoC)? How does it relate to the DSM?
An attempt to (re)map clinical conditions from the bottom up
From genes/cells to behavior and experience
It’s not meant to replace the DSM, but it’s meant to be an addition to the DSM
What is HiTOP?
An attempt to move away from the classical diagnostic classification of the DSM and move toward dimensions of symptoms with a statistical basis
What is the difference between dopamine receptor agonists and antagonists? Give an example of a type of medication for each
Agonists: activates receptors (anti-parkinson)
Antagonists: blocks receptors (antipsychotics)
What is the dopamine hypothesis of schizophrenia?
There are too many dopamine receptors, so antipsychotics are necessary to block some receptors
Why do sometimes dosages of antipsychotics have to be increased?
The initial response of the body to antipsychotics may be to make extra dopamine receptors. Then the dosage has to be higher to block more dopamine receptors
What are Bleuler’s 4 A’s of schizophrenia?
- Ambivalence: decrease goal-oriented actions
- Blunted Affect: decreased emotional expression
- Autism: decreased participation social interactions
- Loosening of Association: incoherent line of thought
What are the 3 categories of symptoms in schizophrenia described nowadays?
- Positive symptoms: hallucinations, delusions
- Negative symptoms: blunted affect, ambivalence, autism
- Disorganization: loosening of association
What percentage of schizophrenics suffer from cognitive impairments?
70-80%
When does the initial psychotic episode usually occur? When do mild cognitive impairments occur?
Initial psychotic: early adulthood
MCI: before first episode
Why does the DSM not include cognitive impairment in their criteria?
Because these symptoms are not specific and are found in many other psychiatric disorders
What 3 social factors contribute to a higher prevalence of schizophrenia?
- Migrants
- Developed countries
- Higher geographical degrees of latitude
What is seen in first-degree relatives of someone with schizophrenia?
They show subclinical symptoms of schizophrenia, often negative symptoms and neurocognitive impairments
What are 3 abnormalities in schizophrenia on the brain level?
- Decreased grey matter volume
- No assymmetry of cerebral hemispheres
- Different white matter pathways between 2 hemispheres
What is the impact of antipsychotic drugs on brain volume?
Enlargement of basal ganglia within 6 months of treatment with antipsychotic drugs
Why are changes in activation of the dorsolateral prefrontal cortex (DLPFC) decreased and increased as well?
Increase with task load of executive functions
Decrease when task load exceeds the capacity, resulting in giving up the task
What does an increase in activity in the amygdala in a person with schizophrenia mean?
It can explain why these patients tend to provide neutral events with an incorrect and emotional interpretation
What is salience? Describe the relation between dopamine and salience in schizophrenia and what the consequence of antipsychotics are in this context
Salience: something standing out to you
Dopamine makes things salient.
Schizophrenia –> more dopamine –> more distractors around us start to attract our attention too –> more things become salient
Antipsychotics –> blocks dopamine and narrows our view
What are the 4 limitations of the dopamine hypothesis of schizophrenia?
- Mainly related to positive symptoms (hallucinations e.g.)
- Not in all patients (non responders)
- Doesn’t explain efficacy of some medications (clozapine)
- Simplistic view of reality
What is the glutamate hypothesis? Why is it a good etiology besides the dopamine hypothesis?
Glutamate is a excitatory neurotransmitter. Blockage of glutamate can induce psychotic symptoms, including cognitive and negative symptoms
It’s a good addition to the dopamine hypothesis, because this hypothesis also accounts for cognitive and negative symptoms
What are 4 lines of evidence for the glutamate hypothesis?
- Accounts for positive, negative and cognitive symptoms
- Glutamate genes are involved in schizophrenia
- Neuroimaging studies
- Excessive glutamate might account for synaptic loss in schizophrenia (SIRS)
In schizophrenia, dopamine is .. (high/low) and glutamate is .. (high/low)
Dopamine: high
Glutamate: low
What are the 6 main cognitive impairments in schizophrenia?
Generalized cognitive impairment
1. Speed of processing
2. Attention/vigilance
3. Working memory
4. Learning and memory
5. Executive functions
6. Social cognition
Which type of symptoms in schizophrenia correlate with cognitive performance and which have a weak correlation?
Disorganized symptoms correlate with cognitive performance
Positive symptoms weakly correlate with cognitive performance
What is the thing people with schizophrenia often want to improve?
Social functioning
What is lower cognitive performance related to besides symptoms?
Reduced social functioning
What is important in treating cognitive problems in schizophrenia?
Using a personalized approach
What is the main difficulty for people with schizophrenia concerning speed of processing?
Automatizing
What are the results of the digit span test for someone with schizophrenia? Explain
It will be very difficult, because working memory is impaired
What is the main difficulty in executive functioning in schizophrenia?
Cognitive flexibility, so being able to switch tasks and adapt
How is social cognition on a lower order and higher order affected in schizophrenia?
Low: basic emotion perception difficulties
High: theory of mind/understanding others is difficult (e.g. false belief task)
What are 4 cognitive styles that fit with schizophrenia?
- Jumping to conclusions
- Source monitoring bias
- Bias against disconfirmatory evidence
- Self-serving bias
What does the false belief taks measure and what is a downside of it?
It measures theory of mind –> low ecological validity
Which task can you use to test the cognitive style of jumping to conclusions?
2 jars of marbles (orange/black)
What can you say about the cognition over the lifespan of someone who is schizophrenic?
Cognitive impairments are there almost entire life. Other symptoms, such as anxiety and social withdrawal have their onset in childhood/adolescence. Prodromal symptoms and psychosis start in adolescence
Why do we have to be careful interpreting results of cognitive tests in schizophrenic persons?
Be careful to translate it to the individual and don’t stick too much to group findings. Schizophrenia is very heterogeneous
What are the 5 symptoms of autism spectrum disorder?
- Persistent deficits in social communication and interaction
- Restricted, repetitive behaviors, interests or activities
- Present in early developmental period
- Significant impairment in functioning
- Not better explained by other things
Why was autism first seen as a symptom of schizophrenia?
In schizophrenia withdrawal into own fantasy life was observed
What are 4 overlapping symptoms of autism and schizophrenia?
- Difficulties with language/speech
- Social withdrawal
- Flattened affect
- Rigid interests
(especially negative symptoms)
What is an issue with measurements for distinguishing autism from schizophrenia?
In some schizophrenia questionnaires, some questions fit autism and schizophrenia criteria
What is the difference in onset between autism and schizophrenia?
Autism: young childhood
Schizophrenia: adolescence
What is the DSM solution to the overlap between autism and schizophrenia?
Criterion F of schizophrenia: if there is a history of autism or a communication disorder of childhood onset, the additional diagnosis of schizophrenia is made only if prominent delusions or hallucinations are present in addition to the other required symptoms of schizophrenia for at least 1 month
Why might taking into account developmental history be a good solution for distinguishing autism and schizophrenia? Why is this difficult?
If you take it into account, you can exclude that being autistic occurs before onset of schizophrenia.
Difficult, because schizophrenics often don’t remember their childhood accurately and there are not a lot of people around them to provide that info
What are the findings of research on psychotic disorders and autistic traits?
Individuals diagnosed with psychotic disorders display high levels of autistic traits
What is the prevalence of psychosis in autistic adults?
9,4%
What is striking in the results of emotion processing and ToM tests for ASD and schizophrenic people?
On average there is no clear difference between these two groups
What is an important difference between autism and schizophrenia?
There is a different underlying neurobiology. Autism has no increase in dopamine and responds badly to antipsychotics
Which approach is necessary to identify how autistic individuals with psychotic symptoms might best be helped?
A transdiagnostic, multi-dimensional approach
Why can’t neuropsychological tests be used to distinguish schizophrenia patients from healthy controls?
All cognitive domains partly overlap with those of healthy controls
How is general cognitive functioning assessed? What are the results of a large study sample of schizophrenics?
With IQ tests –> schizophrenics on average score lower
What is evidence against the assumption that hallucinations and delusions are caused by cognitive impairments?
Studies show a weak relationship
Why can’t impairments in ToM alone explain the development of paranoid delusions?
Many people with schizophrenia perform poorly on ToM without developing paranoid delusions
What is the source monitoring bias?
People who hallucinate have more difficulty than others in distinguishing between their own thoughts and those of other people. They tend to attribute their own voice to another person
What is the attentional bias and the memory bias in schizophrenia?
More attention to stimuli that involve delusional conviction and these stimuli are also better remembered
What do cognitive impairments predict in schizophrenia? (2)
- Social outcomes
- Work performance
(Not predicted by psychiatric symptoms!!)
