chapter 17 anxiety disorders, autistic disorder, adhd, and stress disorders

Chapter 17Chapter 17

Anxiety Disorders, Autistic Anxiety Disorders, Autistic Disorder, ADHD, and Stress Disorder, ADHD, and Stress DisordersDisorders

Anxiety DisordersAnxiety Disorders

A psychological disorder characterized by tension, A psychological disorder characterized by tension, overactivity of the ANS, expectation of an impending overactivity of the ANS, expectation of an impending disaster, and continuous vigilance for dangerdisaster, and continuous vigilance for danger

Two types of anxiety disorders that appear to have Two types of anxiety disorders that appear to have biological causes:biological causes:– Panic disorderPanic disorder– Obsessive-compulsive disorder (OCD)Obsessive-compulsive disorder (OCD)


Panic disorderPanic disorder– Characterized by episodic periods of symptoms such as Characterized by episodic periods of symptoms such as

shortness of breath, irregularities in heartbeat, and other shortness of breath, irregularities in heartbeat, and other autonomic symptoms, accompanied by intense fearautonomic symptoms, accompanied by intense fear

– Onset in young adulthoodOnset in young adulthood– Victim often feels that he or she is going to dieVictim often feels that he or she is going to die– Between panic attacks, people with panic disorder suffer Between panic attacks, people with panic disorder suffer

from from anticipatory anxietyanticipatory anxiety, the fear that another panic , the fear that another panic attack will strikeattack will strike

– Anticipatory anxiety often leads to Anticipatory anxiety often leads to agoraphobiaagoraphobia, fear of , fear of being away from home or other protected placesbeing away from home or other protected places

– Disorder appears to be hereditaryDisorder appears to be hereditary– Strange genetic association between “loose joints” and Strange genetic association between “loose joints” and

panic disorderpanic disorder Patients with joint hypermobility syndrome are more likely to Patients with joint hypermobility syndrome are more likely to

also have panic disorder than control subjectsalso have panic disorder than control subjects


Panic disorderPanic disorder– Previously treated with a combo of behavior therapy and Previously treated with a combo of behavior therapy and

a benzodiazepine (which have strong anxiolytic, or a benzodiazepine (which have strong anxiolytic, or anxiety reducing, effects)anxiety reducing, effects)

Benzodiazepine receptors are located on the GABABenzodiazepine receptors are located on the GABAAA receptor receptor complexcomplex

When benzo binds with receptor, it increases the sensitivity When benzo binds with receptor, it increases the sensitivity of the GABA binding site and produces an anxiolytic effectof the GABA binding site and produces an anxiolytic effect

Anxiety disorders may be caused by decreased number of Anxiety disorders may be caused by decreased number of benzo receptorsbenzo receptors

– SSRI’s used to treat panic disorder and OCDSSRI’s used to treat panic disorder and OCD– Cingulate, prefrontal, and anterior temporal cortices are Cingulate, prefrontal, and anterior temporal cortices are

involved (esp. decrease in activity during panic attacks)involved (esp. decrease in activity during panic attacks)


Obsessive compulsive disorder (OCD)Obsessive compulsive disorder (OCD)– Suffer from Suffer from obsessionsobsessions (an unwanted thought or idea with (an unwanted thought or idea with

which a person is preoccupied) and which a person is preoccupied) and compulsionscompulsions (the feeling (the feeling that one is obliged to perform a behavior, even if one prefers that one is obliged to perform a behavior, even if one prefers not to do so)not to do so)

– Incidence is 1-2% of population; females > males; most Incidence is 1-2% of population; females > males; most commonly begins in young adulthoodcommonly begins in young adulthood

– Compulsions fall into 4 categories: counting, checking, Compulsions fall into 4 categories: counting, checking, cleaning, avoidancecleaning, avoidance

– Some investigators believe that the compulsive behaviors Some investigators believe that the compulsive behaviors are forms of species-typical behaviors (e.g. grooming, are forms of species-typical behaviors (e.g. grooming, cleaning, and attention to sources of potential danger) that cleaning, and attention to sources of potential danger) that are released from normal control mechanisms by a brain are released from normal control mechanisms by a brain dysfunctiondysfunction

– Could also be pathological examples of social ritualsCould also be pathological examples of social rituals


OCD (con’t)OCD (con’t)– May have genetic originMay have genetic origin– OCD is associated with OCD is associated with Tourette’s syndromeTourette’s syndrome (a neurological (a neurological

disorder characterized by tics and involuntary vocalizations disorder characterized by tics and involuntary vocalizations and sometimes by compulsive uttering of obscenities and and sometimes by compulsive uttering of obscenities and repetitions of the utterances of others) that appears in repetitions of the utterances of others) that appears in childhoodchildhood

Treatment for Tourette’s includes antischizophrenic meds that Treatment for Tourette’s includes antischizophrenic meds that block DA Dblock DA D22 receptors receptors

– Many patients that have OCD have tics, and many patients Many patients that have OCD have tics, and many patients with Tourette’s have obsessions and compulsionswith Tourette’s have obsessions and compulsions

– Both disorders may be produced by the same genotypeBoth disorders may be produced by the same genotype– However, some brain damage (esp. to basal ganglia, cingulate However, some brain damage (esp. to basal ganglia, cingulate

gyrus, and prefrontal cortex) may lead to development of OCDgyrus, and prefrontal cortex) may lead to development of OCD


OCD (con’t)OCD (con’t)– Tic disorders ca be caused by a streptococcal infection, Tic disorders ca be caused by a streptococcal infection,

that can damage brain tissuethat can damage brain tissue Esp. by damage to basal gangliaEsp. by damage to basal ganglia

– Increased activity in frontal lobes and caudate nucleus in Increased activity in frontal lobes and caudate nucleus in patients with OCDpatients with OCD

– Some patients with severe OCD have been treated with Some patients with severe OCD have been treated with cingulotomycingulotomy (surgical destruction of the cingulum (surgical destruction of the cingulum bundle, which connects the prefrontal cortex with the bundle, which connects the prefrontal cortex with the limbic system)limbic system)

Helps reduce intense anxiety and the symptoms of OCDHelps reduce intense anxiety and the symptoms of OCD

– Direct pathway (excitatory) in basal ganglia – symptoms Direct pathway (excitatory) in basal ganglia – symptoms of OCD may be a result of overactivity in this pathwayof OCD may be a result of overactivity in this pathway

– Most effective therapy for OCD is drug therapyMost effective therapy for OCD is drug therapy All 5-HT reuptake blockersAll 5-HT reuptake blockers

Autistic disorderAutistic disorder

4 in every 10,000 infants born with this disorder4 in every 10,000 infants born with this disorder A chronic disorder whose symptoms include failure to A chronic disorder whose symptoms include failure to

develop normal social relations with other people, develop normal social relations with other people, impaired development of communicative ability, lack of impaired development of communicative ability, lack of imaginative ability, and repetitive, stereotyped imaginative ability, and repetitive, stereotyped movementsmovements

Afflicts boys 3x more than girlsAfflicts boys 3x more than girls Most autistic people are mentally retarded, but not all areMost autistic people are mentally retarded, but not all are Autistic disorder is one of several pervasive Autistic disorder is one of several pervasive

developmental disorders that have similar symptomsdevelopmental disorders that have similar symptoms– Asperger’s syndrome – less severe, do not include language Asperger’s syndrome – less severe, do not include language

impairment or cognitive deficitsimpairment or cognitive deficits– Rett’s disorder – genetic disorder seen in girls; accompanies Rett’s disorder – genetic disorder seen in girls; accompanies

and arrest of normal brain development during infancyand arrest of normal brain development during infancy– Childhood disintegrative disorder – show normal social and Childhood disintegrative disorder – show normal social and

intellectual develop. until begin to regress sometime b/t ages intellectual develop. until begin to regress sometime b/t ages 2-10 yrs.2-10 yrs.


Autism includes affective, cognitive and behavioral Autism includes affective, cognitive and behavioral abnormalitiesabnormalities

Some investigators suggest that this may stem from Some investigators suggest that this may stem from brain abnormalities that prevent the person from brain abnormalities that prevent the person from forming a “Theory of mind” (i.e. unable to predict and forming a “Theory of mind” (i.e. unable to predict and explain the behavior of other humans in terms of their explain the behavior of other humans in terms of their mental states)mental states)

Imaging studies show great decrease in activity of Imaging studies show great decrease in activity of fusiform face area (region of brain responsible for face fusiform face area (region of brain responsible for face recognition) in autistic individuals while looking at recognition) in autistic individuals while looking at pictures of facespictures of faces


Possible causesPossible causes– HeritabilityHeritability

Some forms appear to be heritableSome forms appear to be heritable 2-3% of siblings of autistic people also have autism2-3% of siblings of autistic people also have autism Concordance rate for monozygotic twins is ~70%Concordance rate for monozygotic twins is ~70% May be associated with specific genetic disorders: May be associated with specific genetic disorders:

Phenylketonuria (PKU)Phenylketonuria (PKU) – caused by inherited lack of an – caused by inherited lack of an enzyme that converts phenylalanine (amino acid in diet) into enzyme that converts phenylalanine (amino acid in diet) into tyrosine; buildup of phenylalanine can cause disruption in tyrosine; buildup of phenylalanine can cause disruption in brain development, and sometimes autismbrain development, and sometimes autism

– Brain pathologyBrain pathology ~20% of all cases of autism have definable biological ~20% of all cases of autism have definable biological

causes, such as rubella, prenatal thalidomide, encephalitis, causes, such as rubella, prenatal thalidomide, encephalitis, etc.etc.

Can result from a wide variety of factors that damage the Can result from a wide variety of factors that damage the brain or impair its developmentbrain or impair its development

Thalidomide (a drug given to pregnant women in 1960s to Thalidomide (a drug given to pregnant women in 1960s to treat morning sickness) caused serious birth defectstreat morning sickness) caused serious birth defects

Attention-Deficit/Attention-Deficit/Hyperactivity Disorder Hyperactivity Disorder (ADHD)(ADHD) A disorder characterized by uninhibited responses, A disorder characterized by uninhibited responses,

lack of sustained attention, and hyperactivitylack of sustained attention, and hyperactivity First shows itself in childhoodFirst shows itself in childhood Usually discovered at schoolUsually discovered at school DSMIV requires the presence of 6 or more of 9 DSMIV requires the presence of 6 or more of 9

symptoms to diagnosesymptoms to diagnose– e.g. difficulty in sustaining attention in tasks of play e.g. difficulty in sustaining attention in tasks of play

activities; easily distracted by extraneous stimuliactivities; easily distracted by extraneous stimuli Diagnosis is often difficultDiagnosis is often difficult Most common treatment is methylphenidate (Ritalin), Most common treatment is methylphenidate (Ritalin),

which inhibits reuptake of DAwhich inhibits reuptake of DA

Attention-Deficit/Attention-Deficit/Hyperactivity Disorder Hyperactivity Disorder (ADHD)(ADHD) Possible causesPossible causes

– Strong evidence for hereditary factors in a person’s Strong evidence for hereditary factors in a person’s likelihood of developing ADHDlikelihood of developing ADHD

– Symptoms may be a result of a “delay of reinforcement Symptoms may be a result of a “delay of reinforcement gradient” (i.e. the longer the delay of some type of gradient” (i.e. the longer the delay of some type of reinforcement for a behavior, the less effective that reinforcement for a behavior, the less effective that reinforcement is)reinforcement is)

– May be caused by underactivity of DA transmissionMay be caused by underactivity of DA transmission Results from human and animal studies contradict each Results from human and animal studies contradict each

other; not clear whether ADHD is caused by excessive other; not clear whether ADHD is caused by excessive number of DA transportersnumber of DA transporters

– Imaging studies showed decreased blood volume in Imaging studies showed decreased blood volume in basal ganglia and cerebellar vermis of boys with ADHDbasal ganglia and cerebellar vermis of boys with ADHD

Stress DisordersStress Disorders

StressStress – a general, imprecise term that can refer – a general, imprecise term that can refer either to a stress response or to a stressoreither to a stress response or to a stressor– StressorStressor – a stimulus (or situation) that produces a stress – a stimulus (or situation) that produces a stress

responseresponse– Stress responseStress response – a physiological reaction caused by the – a physiological reaction caused by the

perception of aversive or threatening situationsperception of aversive or threatening situations The physiological responses that accompany the neg. The physiological responses that accompany the neg.

emotions prepare us to threaten rivals or fight them or emotions prepare us to threaten rivals or fight them or to run awayto run away– Fight-or-flight responseFight-or-flight response – a species-typical response – a species-typical response

preparatory to fighting or fleeing; thought to be preparatory to fighting or fleeing; thought to be responsible for sme of the deleterious effects of stressful responsible for sme of the deleterious effects of stressful situations on healthsituations on health


Physiology of the stress responsePhysiology of the stress response– Autonomic and endocrine responses to emotions: sympathetic Autonomic and endocrine responses to emotions: sympathetic

branch of ANS becomes active, and adrenal glands secrete branch of ANS becomes active, and adrenal glands secrete epinephrine, NE and steroid stress hormonesepinephrine, NE and steroid stress hormones

– Epinephrine affects glucose metabolism, causing nutrients Epinephrine affects glucose metabolism, causing nutrients stored in muscles to become available to provide energy for stored in muscles to become available to provide energy for strenuous exercisestrenuous exercise

– Some of the behavioral and physiological responses produced by Some of the behavioral and physiological responses produced by aversive stimuli appear to be mediated by NE neuronsaversive stimuli appear to be mediated by NE neurons

– The other stress-related hormone is The other stress-related hormone is cortisolcortisol, a , a glucocorticoidglucocorticoid (a (a hormone that has effects on metabolism) secreted by the hormone that has effects on metabolism) secreted by the adrenal cortexadrenal cortex

– Secretion of glucocorticoids is controlled by paraventricular Secretion of glucocorticoids is controlled by paraventricular nucleus of the hypothalamus (PVN)nucleus of the hypothalamus (PVN)

The neurons of the PVN secrete a peptide called The neurons of the PVN secrete a peptide called corticotropin-corticotropin-releasing hormone (CRH)releasing hormone (CRH) which stimulates the anterior pituitary to which stimulates the anterior pituitary to secrete secrete adrenocorticotropic hormone (ACTH)adrenocorticotropic hormone (ACTH), which enters the , which enters the bloodstream and stimulates the adrenal cortex to secrete bloodstream and stimulates the adrenal cortex to secrete glucocorticoidsglucocorticoids


Health effects of long-term stressHealth effects of long-term stress– Many studies of humans who have been subjected to Many studies of humans who have been subjected to

stressful situations have found evidence of ill healthstressful situations have found evidence of ill health– Hans Selye, a pioneer in the study of stress, suggested Hans Selye, a pioneer in the study of stress, suggested

that most of these harmful effects from stress were that most of these harmful effects from stress were produced by prolonged secretion of glucocorticoidsproduced by prolonged secretion of glucocorticoids

Effects include increased blood pressure, damage to muscle Effects include increased blood pressure, damage to muscle tissue, steroid diabetes, etc.tissue, steroid diabetes, etc.

Research with animals shows that long-term exposure to Research with animals shows that long-term exposure to glucocorticoids destroys neurons in field CA1 of glucocorticoids destroys neurons in field CA1 of hippocampus, affecting memory in the long-termhippocampus, affecting memory in the long-term

Severe stress appears to cause brain damage in humans as Severe stress appears to cause brain damage in humans as wellwell


Posttraumatic Stress Disorder (PTSD)Posttraumatic Stress Disorder (PTSD)– A psychological disorder caused by exposure to a situation A psychological disorder caused by exposure to a situation

of extreme danger and stressof extreme danger and stress– Symptoms include recurrent dreams or recollectionsSymptoms include recurrent dreams or recollections– Can interfere with social activities and cause a feeling of Can interfere with social activities and cause a feeling of

hopelessnesshopelessness– Genetic factors play a role in a person’s susceptibility to Genetic factors play a role in a person’s susceptibility to

develop PTSD and to be involved in an event that may develop PTSD and to be involved in an event that may cause PTSDcause PTSD

– Found hippocampal damage in patients with PTSDFound hippocampal damage in patients with PTSD– However, found lower levels of cortisol, instead of However, found lower levels of cortisol, instead of

assumed higher levels (in order to cause brain damage)assumed higher levels (in order to cause brain damage) Exposure to stress increases the number and sensitivity of Exposure to stress increases the number and sensitivity of

glucocorticoid receptors in the hypothalamus and anterior glucocorticoid receptors in the hypothalamus and anterior pituitarypituitary

Instead, high levels of CRH may play a role in the Instead, high levels of CRH may play a role in the development of PTSDdevelopment of PTSD


Stress and cardiovascular diseaseStress and cardiovascular disease– The degree to which people react to potential stressors The degree to which people react to potential stressors

may affect the likelihood that they will suffer from may affect the likelihood that they will suffer from cardiovascular diseasecardiovascular disease

– Individuals who had hyperreacted to a stress test earlier Individuals who had hyperreacted to a stress test earlier in life were more likely to have high blood pressure later in life were more likely to have high blood pressure later in lifein life

– Studies with monkeys demonstrate that individual Studies with monkeys demonstrate that individual differences in emotional reactivity are a risk factor for differences in emotional reactivity are a risk factor for cardiovascular diseasecardiovascular disease

The animals that showed strongest negative reactions to a The animals that showed strongest negative reactions to a threat eventually developed higher rates of coronary artery threat eventually developed higher rates of coronary artery diseasedisease

– Acute stress can also affect cardiovascular diseaseAcute stress can also affect cardiovascular disease Can cause constriction of coronary arteries, arrhythmias in Can cause constriction of coronary arteries, arrhythmias in

heartbeat, stimulation of platelet function (causes forming of heartbeat, stimulation of platelet function (causes forming of clots), and increased viscosity of the bloodclots), and increased viscosity of the blood


The coping responseThe coping response– One of the most important variables that determines One of the most important variables that determines

whether an aversive stimuli will cause a stress reaction is whether an aversive stimuli will cause a stress reaction is the degree to which the stimulus can be controlledthe degree to which the stimulus can be controlled

– Animals can learn coping responses in order to avoid Animals can learn coping responses in order to avoid aversive stimuli, and thus reduce their stress responseaversive stimuli, and thus reduce their stress response

– The opportunity to make a coping response decreases The opportunity to make a coping response decreases the negative impact of stress on the hippocmpusthe negative impact of stress on the hippocmpus


PsychoneuroimmunologyPsychoneuroimmunology– Stress response can impair the function of the immune Stress response can impair the function of the immune

systemsystem– Study of interactions b/t the immune system and Study of interactions b/t the immune system and

behavior is called behavior is called psychoneuroimmunologypsychoneuroimmunology– The immune systemThe immune system

Function is to protect us from infectionFunction is to protect us from infection 2 types of reactions occur when the body is invaded by 2 types of reactions occur when the body is invaded by

foreign organisms:foreign organisms:– Chemically mediated: involves Chemically mediated: involves antibodiesantibodies (proteins produced to (proteins produced to

seek out and destroy seek out and destroy antigensantigens present on invading organisms) present on invading organisms) One type of antibody is released into circulation by One type of antibody is released into circulation by B-B-

lymphocyteslymphocytes, which develop in bone marrow; the , which develop in bone marrow; the antibodies released are called antibodies released are called immunoglobulinsimmunoglobulins, which are , which are chains of proteins that help destroy invading chains of proteins that help destroy invading microorganisms microorganisms

– Cell mediated: produced by Cell mediated: produced by T-lymphocytesT-lymphocytes, white blood cells , white blood cells that originate in thymus glandthat originate in thymus gland

– Communication b/t cells is accomplished by Communication b/t cells is accomplished by cytokinescytokines


PsychoneuroimmunologyPsychoneuroimmunology– Neural control of the immune systemNeural control of the immune system

Stress increases the secretion of glucocorticoids, and these Stress increases the secretion of glucocorticoids, and these hormones directly suppress the activity of the immune hormones directly suppress the activity of the immune systemsystem

Individuals with severe stress showed lowered levels of Individuals with severe stress showed lowered levels of antibodiesantibodies

This suppression is largely mediated by glucocorticoids, This suppression is largely mediated by glucocorticoids, which are mediated by neural activitywhich are mediated by neural activity

– Stress and infectious diseaseStress and infectious disease Stress-producing events can increase a person’s Stress-producing events can increase a person’s

susceptibility to illnesssusceptibility to illness Since the immune system is suppressed, a person is more Since the immune system is suppressed, a person is more

likely to develop an illness after times of stresslikely to develop an illness after times of stress

chapter 17 anxiety disorders, autistic disorder, adhd, and stress disorders

Documents

autistic disorder

neurological disorder

panic disorderpatients

diebetween panic attacks

compulsive behaviors

strikeanticipatory anxiety

compulsionsboth disorders

brain damage