Chapter 17
Anxiety Disorders, Autistic Disorder, Attention-Deficit/Hyperactivity Disorder,
and Stress Disorder
Anxiety Disorders Panic Disorder
Anxiety disorder:• A psychological disorder characterized by
unrealistic fear and anxiety.1. Panic disorder
2. obsessive compulsive behavior Panic Disorder:
• A disorder characterized by episodes of intense fear accompanied by symptoms such as shortness of breath and irregularities in heartbeat.
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Anxiety Disorders Panic Disorder
Anticipatory anxiety:• A fear of having a panic attack; may lead to the
development of agoraphobia.
Agoraphobia:• An unrealistic and intense fear of being away
from home or other protected places.• In severe cases people will not leave home!
Anxiety Disorders
Panic DisorderPossible Causes:
Genetic origins:• Evidence supports some anxiety disorders may
be inherited.Associated with joint hypermobility.
Neurotransmitters:• Serotonin and central benzodiazepine receptors
may be involved in anxiety disorders.• Treated with benzodiazepines and occasionally
SSRIs Brain Structures:
• Imaging studies suggest that the cingulate gyrus, prefrontal, and anterior temporal cortices are involved in panic attack.
Anxiety Disorders Obsessive-Compulsive Disorder
Obsessive-compulsive disorder:• A mental disorder characterized by obsessions
and compulsions.
Obsession:• An unwanted thought or idea with which a person
is preoccupied.
Compulsion:• The feeling that one is obliged to perform a
behavior, even if one prefers not to do so.
Anxiety Disorders
Examples of obsessions: Concern for order Cleanliness, germs Forbidden sexual thoughts
Examples of compulsions: Hand washing Checking Collecting Repeating behaviors (in and out of a door)
Anxiety Disorders Obsessive-Compulsive Disorder Possible Causes:
Genetic Origin:• Evidence is beginning to accumulate suggesting
that OCD might have a genetic origin. Family studies:
• Some research suggests OCD is associated with Tourette’s; a neurological disorder that appears during childhood.
Treatment:
• SSRIs , tricyclic antidepressants (desipramine,
clomipramine)
Copyright © 2004 Allyn and Bacon
Anxiety Disorders Obsessive-Compulsive Disorder Possible Causes:
Tourette’s syndrome:• A neurological disorder characterized by tics and
involuntary vocalizations and sometimes by compulsive uttering of obscenities and repetition of the utterances of others.
• Treatment with antipsycolics (dopamine antagonists, D2)
Anxiety Disorders Obsessive-Compulsive Disorder Possible Causes:
Cingulotomy:• The surgical destruction of the cingulum bundle,
which connects the prefrontal cortex with the limbic system; helps to reduce intense anxiety and the symptoms of obsessive-compulsive disorder.
• Only used on patients who are unresponsive to drug treatment.
Autistic Disorder Description:
Autistic Disorder:• A chronic disorder whose symptoms include
failure to develop normal social relations with other people, impaired development of communicative ability, lack of imaginative ability, and repetitive, stereotypical movements.
Autistic Disorder Possible Causes:
Biological:
• Research and mental health professionals are
convinced autism is caused by biological factors.
• Between 2 and 3 percent of siblings of people
with autism are themselves autistic.
• There is a 70 percent concordance rate for
monozygotic twins.
Copyright © 2004 Allyn and Bacon
Autistic Disorder Possible Causes:
Phenylketonuria (PKU):
• A hereditary disorder caused by the absence of
an enzyme that converts the amino acid
phenylalanine to tyrosine; causes brain damage
unless a special diet is implemented soon after
birth.
Autistic Disorder Possible Causes:
Brain pathology:
• Heritable aspect of autism suggests the disorder
is a result of structural or biochemical
abnormalities in the brain.
• Researchers have found evidence for structural
abnormalities in the brains of autistics, but so far
we cannot point to any single abnormality as the
cause of the disorder.
Attention-Deficit/Hyperactivity Disorder
Attention-deficit/hyperactivity disorder (ADHD):
• The principal characteristics of ADHD are
inattention, hyperactivity, and impulsivity.
These symptoms appear early in a child's life.
• There are three patterns of behavior that indicate
ADHD. People with ADHD may show several
signs of being consistently inattentive. They may
have a pattern of being hyperactive and
impulsive. Or, they may show all three types of
behavior.
Attention-Deficit/Hyperactivity Disorder
Inattention
• Often becoming easily distracted by irrelevant sights and sounds (hyper vigilant)
• Often failing to pay attention to details and making careless mistakes
• Rarely following instructions carefully and completely losing or forgetting things like toys, or pencils, books, and tools needed for a task
• Often skipping from one uncompleted activity to another.
Attention-Deficit/Hyperactivity Disorder
Hyperactivity-Impulsivity
• Feeling restless, often fidgeting with hands or feet, or squirming while seated
• Running, climbing, or leaving a seat in situations where sitting or quiet behavior is expected (lack of impulse control)
• Blurting out answers before hearing the whole question (lack of impulse control)
• Having difficulty waiting in line or taking turns.
Attention-Deficit/Hyperactivity Disorder
Possible causes
• There is strong evidence from family and twin studies for hereditary
factors in a person’s likelihood of developing ADHD.
• Thirty-six percent of all findings were positive (P< 0.05), 17% were
trends (0.05 <P < 0.15), and 47% were negative (P > 0.15).
• Genetic investigations have supported the role of both dopamine D4
receptor gene (DRD4) and dopamine transporter gene (DAT1) in the
vulnerability to the disorder.
• The DRD4 gene has been postulated as a candidate gene for
attention-deficit-hyperactivity disorder
Lower DA binding in basal ganglia
Increased DA transport in frontal lobes
Attention-Deficit/Hyperactivity Disorder
Other causes Possible correlation between the use of cigarettes
and alcohol during pregnancy. Lead paints? Sugar sensitivities? Head injuries?
Attention-Deficit/Hyperactivity Disorder
Brain structure involvement:
• Studies of brain structure of people with ADHD
do not reveal any localized abnormalities,
though the total volume of their brains is
approximately 4% smaller than normal.
• Candidates:
Frontal lobes
Medial temporal lobes
Caudate nucleus
Attention-Deficit/Hyperactivity Disorder
NIMH Child Psychiatry Branch studied 152 boys and girls with ADHD, matched with 139 age- and gender-matched controls without ADHD. The children were scanned at least twice, some as many as four times over a decade. As a group, the ADHD children showed 3-4 percent smaller brain volumes in all regions—the frontal lobes, temporal gray matter, caudate nucleus, and cerebellum.
Attention-Deficit/Hyperactivity Disorder
The Reticular Activating System
• Decreased NE activity in RAS• Poor attention, learning difficulties, memory deficits, lack
of behavior control• Treatment with amphetamines increase RAS activity
• Increased RAS activity• Hyperactivity, restlessness, hyper vigilant• Treatment may include Clonadine (NA Antagonist)
Attention-Deficit/Hyperactivity Disorder Drug Treatment
• Adderall amphetamine• Concerta methylphenidate• Cylert pemoline*• Dexedrine dextro-amphetamine• Ritalin methylphenidate
* DA agonist? Mechanism not well described
Stress Disorders
Stress:
• A pattern of physiology common to all stressors
Stressor:
• A stimulus (or situation) that produces a
generalized stress response.
Stress Disorders
Fight-or-flight response:
• First stage of the stress response where
organism is mobilized.
• Changes in hormonal and sympathetic activity in
preparation for response.
Stress Disorders Physiology of Stress
Glucocorticoid (cortisol)
• One steroid hormone of the adrenal cortex that is
important in protein and carbohydrate
metabolism, secreted especially in times of
stress.
Stress Disorders Physiology of Stress
Corticotropin-releasing hormone (CRH):
• A hypothalamic hormone that stimulates the
anterior pituitary gland to secrete ACTH.
Adrenocorticotropic hormone (ACTH):
• A hormone released by the anterior pituitary
gland in response to CRH; stimulates the adrenal
cortex to produce glucocorticoids.
Copyright © 2004 Allyn and Bacon
Copyright © 2004 Allyn and Bacon
Stress Disorders Psychoneuroimmunology
Psychoneuroimmunology:• The branch of neuroscience involved with
interactions between environmental stimuli, the nervous system, and the immune system.
Antigen:• A protein present on a microorganism that
permits the immune system to recognize the microorganism as an invader.
Stress Disorders Psychoneuroimmunology
Antibody:• A protein produced by a cell of the immune
system that recognizes antigens present on invading microorganisms.
B-lymphocyte:• A white blood cell that originates in the bone
marrow; part of the immune system.
Stress Disorders Psychoneuroimmunology
Immunoglobulin:• An antibody released by B-lymphocytes that bind
with antigens and help to destroy invading microorganisms.
T-lymphocytes:• A white blood cell that originates in the thymus
gland; part of the immune system.
Stress Disorders Psychoneuroimmunology
Cytokine:• A category of chemicals released by certain white
blood cells when they detect the presence of an invading microorganism; causes other white blood cells to proliferate and mount an attack against the invader.