Final Flashcards
What is the definition of Schizophrenia?
a sever, lifelong mental illness consisting of distrubed thinking, abnormal behavior, an inability to understand what is real, and impaired processing of emotions
What are positive symptoms in schizophrenia?
presence of abnormal behaviors (hallucinations, delusions, thoughts of persecution)
What are negative symptoms of schizophrenia?
reduction in normal behaviors (reduced emotional responsiveness, social withdrawal, reduced movemet, lack of motivation)
How long must the schizophrenic symptoms be present in order to be diagnosed?
6 months
What are the five types of schizophrenia?
- paranoid- prominent positive symptoms
- catatonic- predomininant negative symptoms
- disorganized- silly or immature emotional responses
- undifferentiated- does not appropriately fit these categories
- residual- now present less symptoms than they did in the past
What percent of patients exhibit chronic symptoms of schizophrenia? The remaining percent exhibit….
50-70% of patients exhibit chronic symptoms…the remaining 30-50% exhibit residual features
What is treatment resistant schizophrenia? How many patients exhibit this?
exhibit minimal or no improvements afer two trails with either typical or atypical antipsychotic drugs… 1/3 qualify.
When are benzodiazepines prescribed to patients with schizophrenia? What causes the reason?
those with catatonia (negative symptoms)
may be caused by depression, alcohol withdrawal, AIDS
Nearly all patients with schizophrenia have deficits in…
cognitive functioning (working memory, reference memory, attention, executive function)
People with schizophrenia often have poor functional outcomes, what does this mean?
patients inclusion in a community, behaving normally in social situations, successful psychosocial skills are all impraied
What is a sensory gating deficit? What test is used to test for this?
low capacity to filter out unimportant stimuli in the enviornment (misinterpretation of the enviornment…can lead to delusional behavior)
test used: prepulse inhibition procedure…schizophrenia patients have a diminished ability to inhibit a startle response
What is cognitive dysmetria?
abnormalties in processing, coordinating, and responding to information
When is schizophrenia usually first diagnosed?
late teens/early 20s (never really before puberty or after 40)
How many people does schizophrenia affect?
1% of world population (~3 million in the US)
How does schizophrenia affect men and women
equal prevalence in both, but earlier onset in males (18-25) later in women (25-35)
-men will prematurely have poor socail functioning, whereas women portray fewer schizotypal traits
men show more negative symptoms, more withdrawn and passive…women have pos. symptoms (hallucinations and paanoia, more emotional and impulsive–easier to treat)
What happens in the prodromal phase of schizophrenia?
pre-schizophrenia signs characterized by less frequent and less severe symptoms…attention impairment most predictive
exhibit reduced volume of cortical gray matter
What does schizophrenia derive from?
genetic abnormalities, reduced volume of brain structure, and abnormal connectivity among brain structures
most evidence of the derivation of schizophrenia is found in what gene? and what does this gene code for?
disrupted SIDC1 gene (gene codes for a protein important in signaling event that occur within neurons, development of neurons, and cell migration)
What is the most consistent observation in schizophrenic brains?
reduced volume sizes of structures in the left hemisphere and temporal lobe
–also fine decreased volume of frontal lobe, reduced connectivity from thalamus to cerebellum
What is found in the cognitive dysmetria theory?
dysfunctions in connectivity between thalaus and cerebellum…and thalamus and cerebral cortex
leads to abnormal sensory processings, timing functions, and error processings
What is found in the brain during auditory hallucinations, memory tasks, and rest in schizophrenia?
abnormal levels of activity in the hippocampus
What is the neurodevelopmental hypothesis?
abnormal nervous system develoopment leads to irregular neuronal signaling in the brain
–genetics impacts synaptogenesis and myelination
What did early treatments of schizophrenia include?
confinement, induced fevers, convulsive shock therapies, and frontal lobotomies
What drug did Dr. Henri Laborit administer in 1952 which showed a reduction in psychotic symptoms?
preanesthetic agent: chlorpromazine
Most neurotransmission theories in schizophrenia consider abnormalities in what neurotransmitters?
dopamine and glutamate
Positive symptoms in schizophrenia arise from what
increased dopamine release in the LIMBIC SYSTEM
antispcyhotic drugs act as agonists/antagonists on what receptors? resulting in..
antipsychotics act as antagonists on D2 receptors (dont trigger postsynaptic response)…releases dopamine–positive symptoms
what effect does amphetamine have on schizophrenia
causes psychotic symptoms through the increase of dopamine release
What does an increase in dopamine release from mesolimbic dopaminergic neurons result in? where do they terminate?
results in positive symptoms–terminates in nucleus accumbens
What is the glutamate hypothesis?
there is a decreased release of glutamate throughout the cerebral cortex and limbic system
What was the first typical antipsychotic drug?
chlorprozamine
are typical antipsychotics better at treating negative or positive symptoms?
positive symptoms…have a weak efficacy for negative symptoms and cognitive impairement
What are extrapyramidal side effects?
adverse effects consisting or tremor, msucle rigidity, and involuntary movements associated with TYPICAL antipsychotic drugs
in many ways, EPS resemble Parkinsons
What causes EPS?
antagonism of D2 receptors in the basal ganglia (typical antipsychotics)
are atypicals or typicals better at reducing negative symptoms and cognitive impairment?
atypicals
What’s the difference of the mechanism of action of typical and atypical antipsychotics?
typical: mainly through blockade of D2 receptors
atypical: through bloackade of D2 receptors and 5HT2A receptors
Today, if typical antipsychotics are prescribed, what is also prescribed with it?
muscarinic receptor agonist to reduce EPS severity (Benztropine)
but this further impairs cognitive functioning
What is tardive dyskinesia?
a motor disorder affects mainly facial muscles–adverse effects may not occur until a patient stops taking medications but can still persist for a long time after discontinuation
what is neurolepic malignant syndrome?
resembles flu-like symptoms and bloop pressure changes…ANS changes and EPS
what is hyperolactinemia?
occurs from high prolactin in the blood…decreases lactionation and libido…erectyle dysfunction. D2 receptor regulates prolactin from anterior hypothalamus
What are antiemetic effects?
reduce nausea and vomiting.
nausea and vomiting occur from activtion of where?
chemoreceptor trigger zone (area in medulla unprotected by the blood brain barrier)…sends signals to area postrema which elecits vomiting
What effect does 5HT3 antagonism have?
linked to antiemetic effects
some typical antipsychotics have this effect
What is the first line treatment for schizophrenia?
atypical antipsychotic drugs
which drug was the first atypical antisychotic?
clozapine (Clozaril)
Why was clozapine declared as the first atypical antipsychotic?
there was a lack of EPS…led to the development of olanzapine and risperidone
What effect do atypical antipsychotic drugs have on schizophrenia?
reduce positive and negative symptoms and lower the risk of EPS…may improve cognitive functioning…may reduce depression
What adverse effects do atypical antipsychotics carry?
EPS at HIGH doses, risk of neuroleptic malignant syndrome, may produce hyperolactinemia
-significant increases in body weight, risk of type II diabetes
QT interval prolongation-cardiac arrest
have lower risk but not absence of adverse risks than typicals
what adverse effects could clozapine cause?
slight risk of agranulocytosis (low WBC count)
Which atypical antispychotic is preferred to be used as an antiemetic?
Olanzapine–antagonisitc actions at D2 and 5HT3 receptors
what is the serotonin dopamine hypothesis?
drug effects derive from preferntial antagonism of 5HT2A receptors compared to D2 receptors
What is the fast D2-off hypothesis?
rapid dissociation of a drug from a D2 receptor
typicals SLOWLY dissociate, atypicals don’t block D2 receptors for as long a time
What other receptors do antipsychotic drugs bind to other than dopamine and serotonin?
alpha 2 (combined with D2 antagonist–> atypical antipsychotic effects)
clozapine: antagonism of histamine H1 receptor (causes drowsiness)
H1+5HT2C: weight gain and increased risk of diabetes
What are third-generation antipsychotic drugs?
drugs that produce antipscyhotic effects through mechanisms of action different from those of typical and atypical antipsychotic drugs
What is the best known third-generation antipsychotic drug? and what is its mechanism of action?
Aripiprazole (Abilify) is a wek partial agonist for D2 receptors
shares antagonistic effects at 5HT2A (similar to atypicals)
unlikely to produce EPS…less effective than olanzapine for treating schizophrenia but might offer less risk of type II diabetes
What is an antipsychotic depot injection?
provides a slow release of antipsychotic drug, over the course of weeks, after a single injection
-preferred in situations when patients do not comply with their prescribed treatment regime
definition of autism
neurodevelopmental disorder conssisting of social impairments, verbal and nonverbal language difficulties, irritability and repetitive behaviors
what are the genetic links found in autism?
- usually found in both twins
- abnormalities in chromosomes 4 and 7…causes abnormal connectivity in prefrontal cortex, which may have implications in cognitive, social, and emotional features; visual system may be out of sync with activity in motor system
What medicines can be given to people with autism? What are the risks?
aripiprazole and risperidone…reduce autism-related irritability
risks: weight gain, fatigue, EPS–> more common in children than adults
In schizophrenia, where is dopamine high/low according to the glutamate hypothesis?
low in cortical, high in limbic system
What do low levels of dopamine in the prefrontal cortex result in?
cognitive impairment and negative symptoms
What increases dopamine concentration in the prefrontal cortex?
atypical antipsychotics (not typical) clozapine and risperidone increase DA concentration
What is the result of diminished dopamine release in the prefrontal cortex? (next step)
fails to excite glutamate neurons
negative symptoms
What does diminished glutamate release result in? (Next step)
fails to excite mesocortical dopamine neuron activity
and fails to excite GABA neurons (negative symptoms)
What does diminished GABA release result in? (next step)
fails to diminish mesolimbic dopamine activity
What happens when no gaba can diminish the mesolimbic dopamine activity ? (next step)
excess dopamine release occurs in the nucleus accumbens (positive symptoms)
Does haloperidol have an impact on dopamine levels in the prefrontal cortex?
no. it is a typical antipsychotic (D2 agonist) and does not have an effect on dopamine levels unless is it combined with a 5HT2A agonist
What effect does 5HT2A receptor have on dopamine?
dopamine brake.when serotonin is released onto the postsynaptic 5HT2A receptor, dopmine neuron is inhibited
What effet does the 5HT1A receptor have on dopamine?
5HT1A is an autoreceptor which inhibits serotonin release…so when ligand binds, cannot be activated nd the dopamine brake is NOT applied.
dopamine neurons lose inhibition of action of 5HT via 5HT2A receptors (disinhibition)
–there is an increase in dopamine
How does 5HT2A antagonism make an antipsychotic atypical?
stimulates dopamine release…receptor brake is disrupted by the antagonist, which disinhibits dopamine neuron and increases dopamine release
reduces EPS and reduces negative symptoms
What effect does 5HT1A agonism have on glutamate?
reduces it. reduces positive symptoms
definition of fear
negative emotion caused by a real or perceived imminent danger/threat
defiintion of anxiety
worry and distress concerning potential events or outcomes
what is a specific phobia?
anxiety provoked by exposure to specific objects/situations
what is panic disorder?
consists of repeat occurrences of panic attacks
what is agorophobia?
profound fear of being in a situation from which escape is difficult or embarrassing
what is the prevalence of anxiety disorders?
7.3% worldwide, 2x as common in females
what is the most associated factor with developing anxity?
childhood abuse
what is the amygdala responsible for?
a critical structure for fear and anxiety (increased activity)…less involved in OCD
-relating stimuli or events to fear and for mediating the physiological and psychological response to fear
Where is there abnormal functioning in OCD?
thalamus, cingulate cortex, preforntal cortex, basal ganglia, and nucleus accumbens
in the nervous system, the what brain structure sends sensory information to the amygdala?
the thalamus
what is the thalamo-amygdala pathway
sends unprocesses sensory info directly to amygdala “short route”
provides only basic features of the stimulus
what is the thalamo-cortical-amygdala pathway?
information is processed in the cebreal cortex “long route”
info about stimulus
if context of environment is important, then info sent from hippocampus
prefrontal cortex can reduce amygdala activity
what is the early immediate gene?
a gene rapidly activated in response to stimuli
- c-fos becomes activated in response to stimuli
- channelrhodopsin…used to demonstrate how activation of appropriate neurons led to fear response even in places the animals had never been fear conditioned
When the amygdala receives fear-related stimulus, where does it send output signals to?
prefrontal cortex, hyppothalamus, and locus coeruleus
what does the prefrontal cortex play a role in?
in determining how we behave in a fearful situation
what do the hypothalamus and locus ceroulus play a role in?
facilitate physiological reactions to fear…activated sympathetic nervous system>release of epinephrine from adrenal gland
what is the general adaptation syndrom?
stress syndrome occurring in three progressive phases: alarm, resistance, and exhaustion
what is the alarm stage of the general adaptation syndrome?
increased physiological arousal in preparation for an emergency situation…hypothalamus activates sympathetic nervous system
what is the resistance stage of the general adaptation syndrome?
sustained level of physiological arousal…hypothalamus elicits the release of ACTH from pituitary gland; adrenal gland releases cortisol
what is the exhaustion phase of general adaptation syndrome?
fatigue, suceptibility to disease…immune system and metabolic activity of organs throughout the body are underactive
What can prolonged increases in cortisol lead to?
damage to the hippocampus…impairments in memory
what is the tonic phase?–cortisol
baseline state…altered cortisol levels before event or during normal day
what is the phasic phase of cortisol
occurs during a stressful event