lecture 21 Flashcards
Schizophrenia is a mental disorder that is characterized by what
ial withdrawal, disorganized thinking, abnormal speech, and an inability to understand reality
Schizophrenia impacts how many people
It afflicts approximately 1% of world’s population. Symptoms typically come on gradually, begin in young adulthood, and in many cases never resolve (although 20% of people eventually do quite well). About 30-50% of people with schizophrenia do not believe they have an illness or comply with their recommended treatment
Schizophrenia literally means what
split mind, but it does not imply a split personality or multiple personality.
The symptoms of schizophrenia are often grouped into 3 categories:
Negative:
Cognitive:
Positive:
what are negative symptoms of Schizophrenia
the absence of behaviours - social withdrawal, reduced emotional expression, poverty of speech, and reduced motivation
what are cognitive symptoms of Schizophrenia
disorganized and irrational thinking, deficits in learning and memory, poor abstract thinking, and poor problem solving
what are positive symptoms of Schizophrenia
the presence of delusions (typically delusions of persecution, grandeur, or control - beliefs that contradict reality) and hallucinations (perception of stimuli that are not actually present)
what symptoms emerge first (Schizophrenia)
Negative symptoms typically emerge first, followed by cognitive symptoms and, years later, by positive symptoms
Many patients with schizophrenia also exhibit neurological symptoms, such as what
poor control of eye movements and unusual facial expressions, and the illness is associated with subtle differences in
brain structure.
The causes of schizophrenia include what
environmental and genetic factors
Estimates of the heritability of schizophrenia is….
around 80%. Heritability measures the fraction of phenotype variability that can be attributed to genetic variation.
Risk of developing schizophrenia if…
your sibling has it is ~8%
– one of your parents has it is ~13%
– both of you parents have it (or an identical twin has it) is ~50%
about what % of cases are attributed to rare gene copy number variations (schizophrenia)
Around 5% of cases are attributed to rare gene copy number variations (duplicated or missing genes), which are frequently comorbid with autism and intellectual disabilities
The causes of schizophrenia include environmental and genetic factors.
Environmental factors:
mother’s nutrition during pregnancy – mother’s stress during pregnancy – certain infections (particularly during pregnancy) – birth month – being raised in a city – childhood trauma – social isolation – perinatal hypoxia / brain damage
Some evidence suggests that the concordance rate for schizophrenia is much higher for monochorionic twins and than in dichorionic twins, which suggests what
prenatal environment is an important factor
Evidence indicates that incidence of schizophrenia is related to several environmental factors that could affect development in utero:
season of birth, viral epidemics, population density, and substance abuse
what is The seasonality effect:
a disproportionately large number of schizophrenic patients are born in February, March, April, and May
The number of schizophrenic births in late winter and early spring is especially high if the temperature was _____ than normal during previous autumn
lower
The number of schizophrenic births in late winter and early spring is especially high if the temperature was lower than normal during previous autumn
WHY IS THIS
This condition keeps people indoors and favors transmission of viral illnesses
higher change of getting schizophrenia if you live in rural or urban areas?
Schizophrenia is also about three times more prevalent in people who live in the middle of large cities as compared to those who live in rural areas
– This result suggests transmission of infectious illnesses is facilitated by increased population density
how does vitamin d play a role in the likelihood of getting schizophrenia
Although cold weather and crowding may contribute to seasonality effect by increasing likelihood of infectious illness, another variable may also play role: vitamin D deficiency
• Northern European researchers have observed threefold increase in incidence of schizophrenia in immigrants and children of immigrants—especially in dark-skinned people who moved up north
• Another environmental risk factor for development of schizophrenia is parental smoking
when do symptoms of schizophrenia start
Symptoms of schizophrenia are not normally seen in childhood, however behavioral and anatomical evidence indicates that abnormal prenatal development is associated with schizophrenia
what are some Behavioural symptoms of children who go on to develop schizophrenia
Children who go on to develop schizophrenia display less sociability and deficient psychomotor functioning as kids.
what are some Anatomical symptoms of children who go on to develop schizophrenia
Minor physical abnormalities are often seen in children who go on to develop schizophrenia, such as partial webbing of the two middle toes and a high- steepled palate.
Many studies have found evidence of______ in CT and MRI scans of schizophrenic patients
loss of brain tissue
is Schizophrenia a neurodegenerative disease
Schizophrenia is not a neurodegenerative disease
The main treatment of schizophrenia is what
antipsychotic medication, often in combination with psychological and social supports
what is The Dopamine Hypothesis
excessive dopamine D2 receptor activity, particularly in the nucleus accumbens (striatum), underlies the positive symptoms of schizophrenia.
Many drugs have been developed that relieve the positive symptoms of schizophrenia. They are called antipsychotics or neuroleptics and they all block dopamine D2 receptors.
• In contrast, dopamine receptor agonists, like crystal meth and cocaine, tend to temporarily elicit certain aspects of the positive symptoms of schizophrenia in people who do not have the disorder.
positive symptoms of schizophrenia can often be managed with what
dopamine D2 receptor antagonists
Although the positive symptoms of schizophrenia can often be managed with dopamine D2 receptor antagonists, these drugs do not significantly reduce what
the negative symptoms of the disease
Some evidence suggests that the negative symptoms of schizophrenia result from what
abnormal brain activity in the prefrontal cortex.
Some evidence suggests that the negative symptoms of schizophrenia result from abnormal brain activity in the prefrontal cortex.
– For example, the negative symptoms of schizophrenia are similar to those produced by damage where
to the prefrontal cortex, and schizophrenic patients do poorly on neuropsychological tests that are sensitive to prefrontal damage
In general, the negative symptoms of schizophrenia may be caused by what
hypofrontality
what is hypofrontality
decreased activity of the frontal lobes, particularly the dorsolateral prefrontal cortex, which may relate to hypoactivity of D1 receptor activity in this area
While excess dopamine signaling in the striatum has been associated with the positive symptoms of schizophrenia, reduced dopamine signaling in the prefrontal cortex has been associated with what
the negative symptoms
is it possible that schizophrenics have too little dopamine in the prefrontal cortex and too much elsewhere.
yes
The atypical antipsychotic clozapine has been found (in monkeys) to do what
simultaneously decrease dopamine levels in the striatum and increase dopamine levels in the prefrontal cortex
what are Atypical antipsychotic medications
Recently developed medications which aim to reduce both the positive symptoms and negative symptoms of schizophrenia. They typically influence the activity of several neurotransmitter receptors (beyond blocking the dopamine D2 receptor).
what is Clozapine
First of the atypical antipsychotic medications. It blocks both dopamine D2 and serotonin 2A receptors
what is Aripiprazole
An atypical antipsychotic. It acts as partial agonist at the dopamine D2 and D3 receptors. It is thought to reduce dopamine receptor activity in the striatum (nucleus accumbens) but boost it in the prefrontal cortex.
The atypical antipsychotic Aripiprazole is a what
partial dopamine D2 receptor agonist
what is A partial agonist
a drug with very high affinity for a receptor but it activates it less than the normal ligand does.
A partial agonist can act as what
an agonist in regions of low concentration of normal ligand and as antagonist in regions of high concentrations
define Affect
As a noun, affect refers to feelings or emotions
Just as the primary symptom of schizophrenia is disordered thoughts, mood affective disorders (mood disorders) are characterized by disordered feelings
what is Mood (affective) disorder
Serious mood disorder
There are two principal types of mood disorders:
bipolar disorder and major depressive disorder
are Affective disorders dangerous
prevalent and dangerous
who has affective disorders
In adults, almost 12% of women and 8% of men have had a mood disorder in the past year
Severely depressed people usually feel…
unworthy, hopeless, and have strong feelings of guilt
Person who suffers from major affective disorder runs considerable risk of death by what
suicide
what is Bipolar disorder
Serious mood disorder characterized by cyclical periods of mania and depression.
It affects ~1% of the population.
~80% of the risk is attributed to genetics
what is Major depressive disorder (MDD)
Serious mood disorder that consists of unremitting depression or periods of depression (that do not alternate with periods of mania).
Prevalence rates vary widely (3-20%). ~40% of the risk is attributed to genetics
Environmental factors for mood disorders include what
traumatic/abusive childhood experiences
people with BIPOLAR DISORDER have episodes of what
Mania
what is Mania
Episodes of mania are characterized by sense of euphoria that does not seem to be justified by circumstances
• People with mania usually exhibit nonstop speech and motor activity
Diagnosis of mania is partly a matter of what
degree; one would not call exuberance and a zest for life pathological
what are the BIOLOGICAL TREATMENTS FOR BIPOLAR
Lithium
what is lithium
Chemical element
Lithium salts are used to treat bipolar disorder
lithium is Most effective in treating what
manic phase of bipolar affective disorder
Once mania is eliminated, does depression follow
not usually
is lithium understood fully
Therapeutic effect of lithium is very rapid. The mechanism of action is unknown
There are several established and experimental biological treatments for major depressive disorder (MDD):
Drugs that increase serotonin and/or norepinephrine signaling by inhibiting their enzymatic breakdown (e.g., monoamine oxidase inhibitors, MAOi) or by blocking their reuptake (e.g., tricyclics and serotonin specific reuptake inhibitors, SSRIs). – Ketamine (NMDA glutamate receptor blocker) – Electroconvulsive therapy (ECT) – Deep brain stimulation – Transcranial magnetic stimulation – Vagus nerve stimulation – Bright-light therapy (phototherapy) – Sleep deprivation
what is Tricyclic antidepressant (BIOLOGICAL TREATMENTS FOR MDD)
Inhibits reuptake of serotonin and norepinephrine but also affects other neurotransmitters;
Named for the molecular structure
explain Serotonin specific reuptake inhibitor (SSRI)
BIOLOGICAL TREATMENTS FOR MDD
A class of drugs that specifically inhibit the reuptake of serotonin without affecting the reuptake of other neurotransmitters. The most common one is Prozac (fluoxetine). Similar drugs are Celexa, Paxil, Zoloft, etc...
explain Serotonin and norepinephrine reuptake inhibitor (SNRI)
(BIOLOGICAL TREATMENTS FOR MDD)
Antidepressant drug that specifically inhibits reuptake of norepinephrine and serotonin without affecting reuptake of other neurotransmitters.
what is the MONOAMINE HYPOTHESIS
Based largely on the success tricyclic and SSRI treatments, the monoamine hypothesis of depression was
developed. The idea is that depression is caused by insufficient monoamine receptor activity (the monoamines are serotonin, norepinephrine, and dopamine).
Because symptoms of depression are generally not relieved by potent dopamine receptor agonists such as amphetamine or cocaine, most investigators have focused their research efforts on the other two monoamines: norepinephrine and serotonin.
what is the Tryptophan Depletion Procedure
Tryptophan is the molecular precursor to serotonin. Giving people a low-tryptophan diet and then a tryptophan-free amino acid cocktail lowers brain tryptophan levels and consequently decreases their synthesis of serotonin (5-HT).
• Although SSRIs and SNRIs increase the levels of 5-HT and norepinephrine in the brain very rapidly, the drugs do not relieve symptoms of depression until they have been taken for several weeks
• This suggests that something other than a simple increase in monoamine receptor activity is responsible for the normalization of mood
what is Electroconvulsive therapy (ECT)
Used therapeutically to alleviate severe depression and bipolar disorder.
• Seizures are electrically induced by applying brief electrical shocks to the head
• In contrast to the delayed therapeutic effects seen with monoamine related treatments, the effects of other treatments (including ECT, lithium, DBS, VNS, and sleep deprivation) are more rapid. The seizures induced by ECT often reduce symptoms within days.
what is the ROLE OF THE FRONTAL CORTEX in mood disorders
Functional imaging scans have been done on many depressed patients, both before and after a variety of successful treatments.
• There are few (if any) correlations. However, the argument has been made that one area of the anterior cingulate cortex (the subgenual region known as area 25) becomes less active after successful treatments.
what is deep brain stimulation
Deep brain stimulation has been tried in the subgenual anterior cingulate cortex as well as in the nucleus accumbens
• Other promising approaches involve transcranial magnetic stimulation (TMS) directed to areas of the PFC or vagal nerve stimulation (VNS).
One of the most prominent symptoms of depression is what
disordered sleep
what is the role of sleep in people with symptoms of depression
The sleep of people with depression tends to be shallow
• The amount of stage 1 sleep that depressed people have is increased (i.e., their light sleep). Their slow- wave deep sleep is reduced (stages 3 and 4).
• Their REM sleep tends to occurs earlier in the night than for other people, soon after falling asleep.
• Their sleep is also fragmented – they tend to awaken frequently, especially toward morning
what is Total Sleep Deprivation
One of most effective antidepressant treatments is total sleep deprivation
One of most effective antidepressant treatments is total sleep deprivation, how does this work
Total sleep deprivation has immediate antidepressant effects on depression
• Typically, depression is lifted by staying up overnight, but it returns after a normal night’s sleep
• This suggests that during sleep the brain produces a chemical that has antidepressant effect.
• REM sleep deprivation also works, although more slowly, over the course of several weeks (similar to SSRIs).
define Anxiety disorder
a variety of psychological disorders characterized by unrealistic and unfounded fear and anxiety. Includes tension, over activity of the autonomic nervous system, expectation of an impending disaster, and continuous vigilance for danger.
define Generalized anxiety disorder
Disorder characterized by excessive anxiety and worry serious enough to cause disruption of their lives
what is Social anxiety disorder
Disorder characterized by excessive fear of being exposed to the scrutiny of other people that leads to avoidance of social situations in which person is called on to perform
what is Panic disorder
what is Disorder characterized by episodic periods of severe and unremitting terror. Includes symptoms such as shortness of breath, irregularities in heartbeat, and other autonomic symptoms, accompanied by intense fear
what is Anticipatory anxiety
Fear of having a panic attack promotes anticipatory anxiety that sometimes leads to the development of agoraphobia
define Agoraphobia
Fear of being away from home or other protected places
do people just have one type of anxiety disorder
People often have more than one type of anxiety disorder
The cause of anxiety disorders is what
combination of genetic and environmental factors.
Environmental risk factors fo anxiety include what
history of child abuse and poverty.
Anxiety disorders often occur with what
other mental disorders, particularly major depressive disorder, personality disorder, and substance use disorder. Older people who have dementia often have problems with anxiety.
about how many people are affected by an anxiety disorder in a given year.
About 12%
do more women or men get anxiety
It appears twice as often in females as males and generally begin before the age of 25.
12% of people will develop a specific phobia and 10% will develop what
social anxiety disorder at some point in their life
explain ANXIETY DISORDER’s BRAIN ACTIVITY
Functional brain imaging studies suggest that the amygdala and prefrontal cortex are involved in anxiety disorders
• Adolescents with generalized anxiety disorder showed increased activation of the amygdala and decreased activation of the ventrolateral prefrontal cortex while looking at angry faces
• College students with a high level of anxiety showed increased activation of the amygdala, which positively correlates with students’ anxiety measures
what is used to treat anxiety
Benzodiazepines are often used for emergency medical treatment for anxiety disorders because therapeutic effects of these drugs have rapid onset
• However, they are less satisfactory for long-term treatment, as they cause sedation, induce tolerance, and they have a potential for abuse
• For these reasons, researchers have been seeking other drugs to treat anxiety disorders. Selective serotonin
reuptake inhibitors are frequently considered as a first line treatment for anxiety disorders
OCD is characterized by what
a need to repeatedly check things, repeatedly perform certain routines (“rituals”), or repeatedly having certain thoughts (“obsessions”).
The compulsive behaviours often include what
hand washing, cleaning, counting things, or checking things (e.g., to see if a door is locked).
The obsessions are often about what
germs and bodily fluids
do most adults with OCD realize that their behaviours do not make sense
yes
OCD impacts how many
about 2%
who is more likely to get OCD
Females may be slightly more likely than males to get
the diagnosis
• OCD most commonly begins in young adulthood (before age 25)
• The cause of OCD is a combination of genetic and environmental factors. Genetic factors account for ~50% of the variability.
• Environmental risk factors include a history of child abuse or other adverse events. Some cases have been documented following infections.
what is the treatment of OCD
Treatment always involves counseling, often a version of cognitive behavioral therapy (CBT) known as exposure
and response prevention, which involves increasing exposure to what causes the problems while not allowing the repetitive behavior to occur.
• Treatment sometimes includes antidepressants such as selective serotonin reuptake inhibitors (SSRIs)
• Without treatment, the condition often lasts decades.
• Deep brain stimulation within basal ganglia areas is an active area of research.
OCD symptoms CAN appear after…
Sometimes OCD symptoms appear after brain damage, particularly to basal ganglia, cingulate gyrus, or prefrontal cortex
Several functional imaging studies have found evidence of increased activity where
in the frontal lobes and striatum in patients with OCD
Treatment for severe cases of OCD can include a brain lesion, specifically a cingulotomy… what is this
the cutting of a fiber bundle between PFC and anterior cingulate.
