Schizophrenia Flashcards
_____of slightly harmful gene variants create conditions where mental illness is likely
Combinations
In schizophrenia, neural network ____ makes it hard to understand reality and function.
Activity
The concordance rate for schizophrenia among genetically identical twins is about __%
50
When one twin has schizophrenia, the other twin has a __% chance of
developing it, regardless of whether they were raised together or separated at birth.
50
Schizophrenia primarily reflects a ____ predisposition
Genetic
Is there a beneficial “right” combination of schizophrenia genes ?
No, the siblings of schizophrenics have average fertility rate and cognitive abilities
The common gene variants that are associated with an increased risk of developing schizophrenia are also associated with an increased risk of developing…
Bipolar disorder, depression, autism, OCD, and ADHD.
Gene variants reflect a vulnerability to developing any ____ _____ (not specific)
Mental illness
3 reasons mental disorders do not seem to be discrete, unitary diseases
1.Heterogeneity within diagnostic categories
2. Comorbidity
3. Spectrum with normality
Similar behavioural symptoms can arise from completely different ___ _____ disruptions
Neural circuits
Many of the gene variants associated with an increased risk of mental illness regulate brain _____and neural _____.
Development and plasticity
Gene variants do not _____ cause mental illness.
Directly
Gene variants collectively compromise the interactions of various ____ and cell types in the brain
Proteins
People who present with seemingly similar types of mental illness rarely share the same___ _____
Gene variants
Human brain development is highly complicated, but it is also ____ (people can thrive under a lot of adversity).
Robust
There is a certain amount of unavoidable randomness (ex. ligand not binding) at the _____ level that impacts brain development and maturation
Molecular
Our _____ has evolved to buffer many insults – environmental variation, genetic variation, and molecular noise.
Genome
Our genome contains redundancies, ____ checking mechanisms, and quality control
effort
Error
Genetic instructions allow gene variations to accumulate in the
population if the _____ mutations are not too severe.
Individual
The bodies of bilateral creatures are largely symmetrical, and the two sides develop
independently from the same set of _____ instructions
Genomic
Highly symmetrical bodies reflect ___ genetic instructions
Clear
Random, uncommon asymmetries suggest the underlying genetic
instructions are _____
Confusing
Body symmetry may be indicative of the robustness of the genetic
instructions, which must contend with ______ variation and molecular noise.
Environmental
Body symmetry slightly correlates with…
Intelligence, physical attractiveness, and physical health
There are about ____ protein-encoding genes in the human genome.
20,000
___ of our genes
are expressed in the brain at some point, either during development or adulthood.
Half
Mutations anywhere may increase someone’s risk of
developing a mental illness by creating _____ in neural network function.
Instability
New pharmacological
treatments directly target ____ signaling cascades rather than neurotransmitter signaling.
Intracellular
Closed-loop deep brain stimulation
strategies
An implanted metal wire is used to record brain dynamics and
then deliver stimulation when necessary to correct neural circuit irregularities
Schizophrenia symptoms
Social withdrawal, disorganized thinking, abnormal speech, and an inability to understand reality.
Prevalence of schizophrenia
Nearly 1% of world’s population
When do symptoms of schizophrenia typically begin ?
Young adulthood
About __-__% of people with schizophrenia do not believe they have an illness or
comply with their recommended treatment.
30-50%
First symptom of schizophrenia
Social withdrawal
Cognitive ability usually increases in first 30 years. For schizophrenic people, there seems to be a cognitive ability _____.
Plateau
3 groups of schizophrenia symptoms
Negative, cognitive, positive
Negative schizophrenia symptoms are the ____ of behaviors
Absence (social withdrawal, reduced emotional expression, poverty of speech, and reduced motivation)
Cognitive schizophrenia symptoms
Disorganized and irrational thinking, deficits in learning and memory, poor
abstract thinking, and poor problem solving
2 types of positive schizophrenia symptoms
Delusions and hallucinations
Persecution delusion
Thinking people are out to get you
Grandeur delusion
Thinking you are uniquely amazing
Control delusion
Thinking you control external events (ex. traffic)
Schizophrenia diagnosis depends on how much the delusions affect ____
Functioning
Order of schizophrenia symptoms type
- Negative
- Cognitive
- Positive
Many patients with schizophrenia also exhibit neurological symptoms, such as …
Poor control of eye movements and unusual facial expressions
Estimates of the heritability of schizophrenia are around __%.
80
Heritability measures the fraction of _____ variability that can be attributed to genetic
variation.
Phenotype
5% of schizophrenia cases are attributed to rare gene ___ ____ variations (duplicated or missing
genes)
Copy number
Rare gene mutation schizophrenia is often comorbid with …
Autism and intellectual disabilities
Environmental in utero factors linked to schizophrenia
Season of birth, viral epidemics, population density, and parental smoking.
Schizophrenia is more common in people who live in ___cities/rural areas
Cities
Overall, which has a bigger effect on schizophrenia risk; environmental or genetic factors ?
Genetic
Prenatal environments of monochorionic twins (i.e., they share one placenta and amniotic sac) are more similar than those of _____ twins.
Dichorionic
Some evidence suggests that the concordance rate for schizophrenia is higher for ______dichorionic/monochorionic twins
Monochorionic
Abnormal _____ development is associated with schizophrenia
Prenatal
Children who go on to develop schizophrenia display less sociability and deficient ______ functioning as kids.
Psychomotor
Minor physical _____ are often seen in children who go on to develop schizophrenia,
Abnormalities
Drugs relieve the ____negative/cognitive/positive symptoms of Schizophrenia
Positive
These drugs typically block dopamine D2 receptors (antagonists)
Antipsychotics or neuroleptics
Dopamine receptor _____ agonists/antagonists, like crystal meth and cocaine, tend to
temporarily elicit certainpositive symptoms of schizophrenia in people who do not have the disorder
Agonists
The Dopamine Hypothesis of Schizophrenia
Excessive dopamine D2 receptor activity, particularly in the
nucleus accumbens (striatum) creates positive symptoms of Schizophrenia
Do Dopamine D2 antagonists reduce negative Schizophrenia symptoms ?
No, only the positive
Negative symptoms of schizophrenia are similar to those
produced by damage to the ____ cortex
Prefrontal
Hypofrontality
Decreased activity of the frontal lobes
Particular region of hypofrontality causing the negative symptoms of Schizophrenia
Dorsolateral prefrontal cortex
The dorsolateral prefrontal cortex is linked to hypoactivity of local dopamine D1 ______.
Receptors
Excess dopamine signaling in the _____ is associated with the positive
symptoms of schizophrenia
Striatum
Schizophrenia may be associated with too little dopamine in the _____ cortex and too much dopamine elsewhere.
Prefrontal
Clozapine has been found (in monkeys) to simultaneously _____decrease/increase dopamine levels in the striatum and _____decrease/increase dopamine levels in the prefrontal cortex
Decrease and increase
Atypical antipsychotic medications
Second generation antipsychotics that aim to reduce both the positive symptoms and negative symptoms of schizophrenia.
Atypical antipsychotic medications to treat Schizophrenia
Clozapine, Aripiprazole
Clozapine blocks dopamine D2 and _____ 2A receptors
Serotonin
Aripiprazole as partial _____agonist/antagonist at dopamine D2 and D3 receptors as well as at serotonin 1A receptors.
Agonist
Aripiprazole simultaneously ______decreases/increases dopamine receptor activity in the striatum (nucleus accumbens) while _____decreasing/increasing it in the prefrontal cortex.
Decrease and increase
A partial agonist is a drug with very high _______ for a receptor.
Affinity
A partial agonist can boost receptor activity in regions where
there is ____ concentration of the normal ligand while simultaneously reducing receptor activity in regions where there is _____ concentration of the normal ligand.
Low, high
