Schizophrenia Flashcards
What is the closed loop stimulation strategy in deep brain stimulation
Implanted metal wire is used to record brain dynamics & deliver stimulation when necessary to correct neural circuit irregularities
What are 3 genenral issues with diagnosing of major mental illnesses
- there’s too much heterogeniety within diagnostic categories (2 completely different ppl can be diagosed with same disorder)
- there’s too much comorbidity across categories
- Continuity with normality: We just draw arbitrary lines between what’s normal & problematic
Nearly __% of the world population is schizophrenic
Nearly 1% of the world population is schizophrenic
what is the key component of neurodevelopmental robustness
Symmetry - Highly symmetrical bodies have more robust genetic instructions, which makes them better at dealing with environmental variation & molecular noise
- What’s the typical onset age for schizophrenia
- what’s particular about women aged 40-49 in development of schizophrenia?
- 20-24 (for women & men)
- Women in 40-49 age range are much more likely to develop schizophrenia than men are
Give examples of
1. negative symptoms of schizophrenia
2. positive symptoms of schizophrenia
- negative - absence of behaviours: social withdrawal, reduced emotional expression, poor speech, reduced motivation
- positive - presence of delusions and hallucinations
Give examples of
1. neurological symptoms of schizophrenia
2. cognitive symptoms of schizophrenia
- Disorganized & irrational thinking, deficits in learning & memory, poor abstract thinking, poor problem solving
- Poor control of eye movement & unusual facial expressions
What’s the difference between heritability and concordance of an illness
Heritability - measures how likely it is to develop schizophrenia (or any illness) because of genetics and not environmental factors/bad luck
Concordance - measures likelyhood that you’ll inherit something if someone close to you has it
what’s the heritability of schizophrenia
around 80%
what’s the concordance of schizophrenia for
1. monochorionic twins
2. dichrionic twin or sibling
3. both parents have it
4. 1 parent has it
- monochorionic twins - 50%
- dichrionic twin or sibling - 8%
- both parents have it - 50%
4.1 parent has it - 13%
What does perinatal hypoxia (any complication at birth that prevents oxygen flow to brain) have to do with the likely hood of developing schizophrenia
These complications result in damage/death of neurons, which has some correlation with development of schizophrenia
(reminder, not question) Some environmental causes of schizophrenia are
- Mother’s nutrition & stress during pregnancy
- Infections during pregnancy
(flip for viral infection spread theory)
Viral infection spread theory
Seasonality effect - disproportionately large % of schizophrenic patients are born February, March, April, and May (born in the northern hemisphere)
- People who grew up in large cities more likely to develop schizophrenia than those who grew up in rural area
In childhood, what are some 1. behavioural signs for schizophrenia
2. anatomical signs for schizophrenia
Behavioural - tend to be less sociable & have deficient psychomotor functions
-Anatomical - partial webbing of 2 toes & high steeped palate (& other abnormalities)
What are antipsychotics/ neuroleptics (dopamine D2 antagonists) good for
Although they relieve positve symptoms of schizophrenia and block dopamine D2 receptors but not negative symptoms
What effect does the antipsychotic clozapine have in monkeys
It decreases dopamine levels in the striatum and increase dopamine levels in the prefrontal cortex. Specifically, it blocks dopamine D2 & serotonin 2A receptors
What effects does aripiprazole /abilify/ aristrada have in the human brain
It acts as a partial agonist of dopamine D2 & D3 and serotonin 1A receptors; also reduces dopamine receptor activity in the striatum (nucleus accumbens) & boosts it in the prefrontal cortex
(reminder) how does a partial agonist drug work??
drug with very high affinity for a receptor, but it activates it less than the normal neurotransmitter does, so it can boost👆 receptor activity where there’s low concentration and reduce🤏receptor activity where there’s high concentration of the normal ligand
What’s the dopamine hypothesis for positive symptoms and negative symptoms
hint: excessive dopamine in _____ explain positive symptoms
abnormal activity in ____explain negative symptoms
Theorizes that excessive dopamine D2 receptor activity in the nucleus accumbens (striatum), underlies the positive symptoms of schizophrenia
Theorized that negative symptoms of schizophrenia is bc of abnormal activity in prefrontal cortex
How does hypofrontality correlate with negative symptoms of schizophrenia
hint: increases activity in do____
also relates to hypoactivity in_____
Because it decreases activity in dorsolateral prefrontal cortex; relates to hypoactivity of local D1 receptors
what percentage of the population has a “severe” mental illness?
4%
