lecture 22 Flashcards
Autistic spectrum disorder describes what
a wide range of developmental disorders
Autistic spectrum disorder is characterized by what
They are characterized by troubles with social interaction and communication, and by restricted and repetitive behavior
what are symptoms of autism
In some cases there are clear cognitive impairments, intellectual disability, or reduced imaginative ability.
• Parents usually notice signs during the first two or three years of their child’s life. Social impairments are often the first symptoms to emerge.
• Some infants with autistic disorder do not seem to care whether they are held. Some arch their backs when picked up, as if they do not want to be held.
Mild forms of autistic spectrum disorder often do not include what
a delay in language development or the presence of important cognitive deficits
Mild forms of autism is called what
often called Asperger’s syndrome
Mild forms of autism (often called Asperger’s syndrome) mostly just involve what
deficient or absent social interactions and repetitive and stereotyped behaviors along with obsessional interest in narrow subjects
are autistic people okay with language
Many people with autism have abnormal or even nonexistent language. About a third to a half of individuals with autism do not develop enough natural speech to meet their daily communication needs.
• They may echo what is said to them or they may refer to themselves as others do—in second or third person
People with autism generally have interests in what
atypical interests and behaviors
what kind of movements might someone with autism show
They may show stereotyped movements, such as flapping their hand back and forth or rocking back and forth. They may exhibit compulsive or ritualistic behaviour
autism occurs in how many peole
Incidence of autistic disorder is around 1% of population
autism is more common in men or women
Disorder is four times more common in males than in
females
• If only cases of autism with intellectual disability are considered, the ratio falls to 2:1 (males:females)
• If only cases of high-functioning autism are considered (those with average or above-average intelligence and
reasonably good communicative ability), the ratio rises to approximately 7:1 (males:females)
is autism heritable
It is thought that autism (like intellectual disability) encompasses a large set of disorders with diverse mechanisms. Autism is associated with a combination of genetic and environmental factors (thought to affect brain development in the first few months of gestation in the womb).
• Estimates of the heritability of autism are around 70%, but as high as 90% for autism spectrum disorder.
• The large number of autistic individuals with unaffected family members may result from spontaneous structural variation — such as deletions, duplications or inversions of genetic material.
• Some cases of autism have been linked to maternal viral infections during pregnancy
how is the brain when autistic
There often appears to be significant abnormalities in the development of the brains of autistic children
• Kids who develop autism tend to have a slightly small brain at birth, but it grows abnormally fast and by 2–3 years of age is often about 10% larger than a normal brain
• Following this early spurt, growth of the autistic brain slows down, and by adolescence it is only about 1–2 percent larger than normal.
Hypotheses for the cellular and molecular bases of early brain overgrowth (for autism) include the following:
Altered neuronal migration during early gestation
– Abnormal formation of synapses and dendritic spines – Overconnectivity in key brain regions
– Unbalanced excitatory–inhibitory neural networks
what does an fMRI look like when someone has autism
fMRI studies on people with autism have revealed marked abnormalities in brain activity. For example, there is little or no activity in fusiform face area of autistic adults looking at pictures of human faces
The main goals when treating children with autism are what
to lessen the impact of the associated deficits and family distress, and to increase quality of life and functional independence.
Intensive, sustained special education programs and behavior therapy early in life can help children acquire self-care, communication, and life skills, and often improve functioning and decrease symptom severity and maladaptive behaviors
do medications help autism
Medications generally do not address the core symptoms, but often help reduce the irritability, inattention, and repetitive behaviors. All kinds of medications may be tried, including:
– anticonvulsants (↑ GABA receptor activity)
– antidepressants (↑ serotonin receptor activity) – antipsychotics (↓ dopamine receptor activity) – stimulants (↑ dopamine receptor activity)
what does ADHD stand for
ATTENTION-DEFICIT/HYPERACTIVITY DISORDER
what is ADHD
a mental disorder characterized by problems paying attention, hyperactivity, or difficulty controlling (inhibiting) behavior in an age appropriate manner
when do ADHD symptoms occur
symptoms generally appear before a person is 12 years old, are present for more than six months, and cause problems in school, home, or elsewhere
is it clear when a child has ADHD
The condition can be difficult to distinguish from hyperactivity, inattention, and impulsivity that are still within the range of normative behaviors. Many children with ADHD have a good attention span for tasks they find interesting
ADHD is usually first discovered where
in the classroom, where children are expected to sit quietly and pay attention to teacher or work steadily on project
Symptoms of inattention include what
such things as often had difficulty sustaining attention in work tasks or play activities or is often easily distracted by extraneous stimuli
Children have difficulty withholding a response, act without reflecting, often show reckless and impetuous behavior, and let interfering activities intrude into ongoing tasks
who gets autism
Prevalence rates vary widely across different communities, with a range of 1 to 10% of children. Diagnosis is can be
difficult because symptoms are not well defined. Boys are diagnosed three times more often than girls
ADHD is often associated with what
aggression, conduct disorder, learning disabilities, depression, anxiety, and low self-esteem
The causes of ADHD include what
environmental and genetic factors. Estimated heritability of ADHD ranges from 75 to 91%. Certain cases are related to previous infection of or trauma to the brain.
• Drug and alcohol use and infections during pregnancy are associated with an increase risk for the child, as is low birth weight.
Management of ADHD typically involves what
counseling and medications, often stimulants that raise dopamine levels by blocking or reversing the dopamine reuptake transporter (e.g., Ritalin and Adderall). Antidepressants may also be helpful.
Stress refers to what
the physiological reaction caused by the perception of aversive or threatening situations.
Stress refers to the physiological reaction caused by the perception of aversive or threatening situations.
• These physiological responses accompany what kind of emotions
negative emotions and prepare people for fight or flight situations
Threatening situations generally call what responses (stress)
autonomic and endocrine responses that help to mobilize the body’s energy resources and support vigorous activity
Stress-related autonomic and endocrine responses can cause what
adverse effects on health over time
Stress activates what
the sympathetic branch of autonomic nervous system
– Stress also activates the adrenal glands to release hormones into the blood, including epinephrine, norepinephrine, and glucocorticoids such as cortisol
The autonomic and hormone responses of stress do what
work together to increase heart rate, blood pressure, and blood flow to muscles to make nutrients stored become available
what are Glucocorticoids
group of hormones (corticosteroids) that are important in protein and carbohydrate metabolism, secreted especially in times of stress
what is Cortisol
A specific glucocorticoid (steroid hormone) secreted by adrenal cortex in response to stress
further explain Glucocorticoids (stress)
Help to break down protein and convert it to glucose, to make fats available for energy, increase blood flow, suppress secretion of sex hormones and stimulate behavioral responsiveness, presumably by affecting brain
• Glucocorticoids have other physiological effects, too, some of which are not well understood. Almost every cell in the body contains glucocorticoid receptors, which means that few of them are unaffected by these hormones.
Secretion of glucocorticoids (stress) is controlled by the hypothalamus. explain the process
1) In response to stress, the hypothalamus starts a chain of events by releasing CRH/CRF (corticotropin-releasing hormone/factor).
2) CRH stimulates the pituitary to secrete ACTH (adrenocorticotropic hormone).
3) ACTH stimulates the adrenal gland to produce glucocorticoids.
Short-term effects of glucocorticoids are good or bad
essential for survival.
Long-term effects of glucocorticoids are good or bad
are damaging. These effects include
• increased blood pressure • damage to muscle tissue • steroid diabetes
• infertility
• inhibition of growth
• inhibition of the inflammatory responses • suppression of the immune system
Stressful events in people’s daily lives appear to predispose them to what
upper respiratory infections
shown in monkeys, what are the effects of stress on the brain
Monkeys near bottom of their social hierarchy are almost continuously stressed.
– These monkeys seem to die more often than others from stress- related issues.
– Examinations post-mortem found them to have signs of chronic stress, such as gastric ulcers, enlarged adrenal glands, and damaged hippocampi.
Episodes of emotional maltreatment during childhood has been associated with an average 7.2 percent reduction in volume of what in the brain
dorsomedial prefrontal cortex
what is PTSD
mental disorder that can develop after a person is exposed to a traumatic event, such as sexual assault, warfare, traffic collisions, or other threats on a person’s life.
what are the Symptoms of PTSD
may include disturbing thoughts, feelings, or dreams related to the events, mental or physical distress to trauma-related cues and efforts to avoid them, and an increase in the fight-or-flight response
The symptoms can interfere with social activities, cause feeling of hopelessness, and increase risk for suicide
will everyone who experiences trauma get PTSD
Most people who have experienced a traumatic event will not develop PTSD.
– The likelihood of developing PTSD increases with the number of traumatic events the person has experienced
– Approximately 30% of the variance in PTSD is caused from genetics alone.
– The main treatments for people with PTSD are counselling (psychotherapy) and medication. Selective serotonin reuptake inhibitors (SSRIs) are the first-line medications and result in benefit in about half of people.
Some evidence suggests that PTSD is associated with what
abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis, which coordinates hormonal response to stress
Several studies found evidence that increased activity in the______ is responsible for emotional reactions in people with PTSD
amygdala
Functional imaging studies have found that when shown pictures of faces with fearful expressions, people with PTSD show what
greater activation of amygdala and smaller activation of prefrontal cortex than did people without PTSD
Drug addiction is an extremely serious debilitating disorder. The big players are what
alcohol, opiates, cocaine and meth, nicotine, barbiturates and benzos
what are the Problems with alcohol abuse
automobile accidents • fetal alcohol syndrome • cirrhosis of the liver • Korsakoff's syndrome • increased rate of heart disease • increased rate of intracerebral hemorrhage • pancreatitis, diabetes, etc., etc.
Epidemiological studies estimate that genetic factors account for what % of the risk factors for alcoholism.
40–60%
is Alcohol consumption distributed equally across the population
Alcohol consumption is not distributed equally across the population; in the United States, 10 percent of the people drink 50 percent of the alcohol
Many twin studies and adoption studies confirm that the primary reason for this disparity is genetic
what is Reinforcement (addiction)
Drugs that lead to dependency must first reinforce people’s behavior
If, in a particular situation, a behavior is regularly followed by reinforcement that behavior will become more frequent in that situation
Effectiveness of a reinforcing stimulus is greatest if what
it occurs immediately after a response occurs
If reinforcing stimulus is delayed what happens
it becomes considerably less effective
Effectiveness of a reinforcing stimulus is greatest if it occurs immediately after a response occurs
• If reinforcing stimulus is delayed, it becomes considerably less effective
• The consequences of the actions teach us what
whether to repeat that action, and events that follow a response by more than a few minutes were probably not caused by that response
The speed by which the brain perceives reinforcement is thought to explain what
the relative addictive potential of different drugs, such as heroin versus morphine
what are Neural Mechanisms
All reinforcers, natural (food, water, sex) or otherwise, seem to cause the release of dopamine in the striatum, particularly in the nucleus accumbens
• All addictive drugs rapidly increase dopamine levels in the nucleus accumbens.
• Dopamine release in the nucleus accumbens in not as simple as it sounds, however. Aversive stimuli can also trigger release of dopamine here, and some areas of the nucleus accumbens promote avoidance behaviors. So, it’s complicated.
People with a history of drug use show the same deficits on tasks that involved the what kind of the brain as do people with damage to this region.
PFC
Addicts also show structural abnormalities in the PFC
When addicts (who are not currently high) perform tasks that normally activate the prefrontal cortex, what happens
their medial prefrontal cortex is less activated than that of healthy control subjects, and they perform more poorly on the tasks
In cocaine addicts, the more cocaine they took, the less brain activity in where
their PFC
Studies have shown a high level of comorbidity of what
schizophrenia, ADHD, and substance abuse
70-90% of schizophrenics smoke cigarettes and almost half are addicted to drugs other than nicotine. (It has been estimated that 34% of all cigarettes are smoked by schizophrenics.)
what may be common factor in these disorders (schizophrenia, ADHD, and substance abuse)
Abnormalities in the prefrontal cortex and its interactions with the striatum and dopamine system may be common factor in these disorders
what is
Negative reinforcement
Removal or reduction of an aversive stimulus that is contingent on a particular response, with an attendant increase in the frequency of that response
what is Tolerance
Fact that increasingly large doses of drugs must be taken to achieve a particular effect
Caused by compensatory mechanisms that oppose the effect of the drug. Not all addictive drugs produce tolerance and withdrawal
explain Withdrawal symptoms
Appearance of symptoms opposite to those produced by drug when the drug is suddenly no longer taken
Caused by presence of compensatory mechanisms (that relate to drug tolerance)
what is Methadone maintenance
Potent opiate, similar to morphine or heroin but it has a slow onset and offset.
Methadone maintenance programs administer the drug to their patients in the form of a liquid, which they must drink in the presence of the personnel supervising this procedure
Similar maintenance treatments are used with nicotine addiction (nicotine patches, gum, vaping, etc.)
THERAPY FOR DRUG ABUSE: THE PARTIAL AGONIST APPROACH, explain Buprenorphine
Buprenorphine is a high affinity partial agonist for the μ opiate receptor. It blocks the effects of other opiates, but itself only produces only a weak opiate effect
It is a relatively new treatment for opiate addiction. It is commonly mixed a little naloxone (a opiate receptor antagonist) to reduce the potential for abuse
THERAPY FOR DRUG ABUSE: THE PARTIAL AGONIST APPROACH, explain Varenicline
Approved for therapeutic use to treat nicotine addiction
Serves as partial agonist for nicotinic receptor, just as buprenorphine serves as a partial agonist for μ-opioid receptor
THERAPY FOR DRUG ABUSE:
THE BINDING SITE BLOCKER APPROACH, explain Naltrexone
Opioid receptor antagonist that is prescribed to alcoholics and opiate addicts.
It reduces the high produced by opiates (because the opiates can’t bind to the receptor) but it also tends to reduce drug and alcohol cravings
THERAPY FOR DRUG ABUSE:
THE BINDING SITE BLOCKER APPROACH, explain Naloxone
Extremely rapid (and short lived) opioid receptor antagonist that reverses the effects of an opiate overdose. During an opiate overdose, people can lose consciousness and stop breathing. An injection of naloxone immediately reverses these effects and will actually put addicts into withdrawal.
THERAPY FOR DRUG ABUSE: THE VACCINE APPROACH, explain Cocaine vaccine
Compounds have been developed that cause the person’s own immune system to create antibodies against a drug, like cocaine.
When antibodies bind to the drug, it can no longer cross the blood brain barrier.
This approach is being explored for cocaine, heroin, meth, and nicotine.
THERAPY FOR DRUG ABUSE: THE BRAIN STIMULATION APPROACH, explain DBS
and
TMS
Researchers have tried DBS in many areas of the brain, including the basal ganglia and PFC.
TMS directed toward the PFC is currently being tested
