Developmental and
Cognitive Disorders
Chapter 13
Perspectives on Developmental Disorders
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Normal vs. Abnormal Development
– Childhood is associated with significant developmental changes
– Disruption of early skills will likely disrupt development of later skills
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Developmental Disorders
– Diagnosed first in infancy, childhood, or adolescence
– Attention deficit hyperactivity disorder (ADHD)
– Learning disorders
– Autism
– Mental retardation
Attention Deficit Hyperactivity Disorder (ADHD): An Overview
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Nature of ADHD
– Central features – Inattention, overactivity, and impulsivity
– Associated with behavioral, cognitive, social, and academic
problems
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DSM-IV and DSM-IV-TR Symptom Clusters
– Cluster 1 – Symptoms of inattention
– Cluster 2 – Symptoms of hyperactivity and impulsivity cluster
– Either cluster 1 or 2 must be present for a diagnosis
ADHD: Facts and Statistics
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Prevalence
– Occurs in 4%-12% of children who are 6 to 12 years of age
– Symptoms are usually present around age 3 or 4
– 68% of children with ADHD have problems as adults
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Gender Differences
– Boys outnumber girls 4 to 1
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Cultural Factors
– Probability of ADHD diagnosis is greatest in the United States
ADHD: Biological Contributions
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Genetic Contributions
– ADHD runs in families
– Familial ADHD may involve deficits on chromosome 20
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Neurobiological Contributions: Brain Dysfunction and Damage
– Inactivity of the frontal cortex and basal ganglia
– Right hemisphere malfunction
– Abnormal frontal lobe development and functioning
– Yet to identify a precise neurobiological mechanism for ADHD
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The Role of Toxins
– Allergens and food additives do not appear to cause ADHD
– Maternal smoking increases risk of having a child with ADHD
ADHD: Psychosocial Contributions
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Psychosocial Factors Can Influence the Disorder Itself
– Constant negative feedback from teachers, parents, and peers
– Peer rejection and resulting social isolation
– Such factors foster low self-image
Biological Treatment of ADHD
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Goal of Biological Treatments
– To reduce impulsivity/hyperactivity and to improve attention
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Stimulant Medications
– Reduce the core symptoms of ADHD in 70% of cases
– Examples include Ritalin, Dexedrine
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Effects of Medications
– Improve compliance and decrease negative behaviors in many
children
– Beneficial effects are not lasting following drug discontinuation
– Negative side effects include insomnia, drowsiness, and irritability
Behavioral and Combined Treatment of ADHD
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Behavioral Treatment
– Involve reinforcement programs
– Aim to increase appropriate behaviors and decrease inappropriate
behaviors
– May also involve parent training
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Combined Bio-Psycho-Social Treatments
– Are highly recommended
Learning Disorders
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Scope of Learning Disorders
– Problems related to academic performance in reading,
mathematics, and writing
– Performance is substantially below what would be expected
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DSM-IV and DSM-IV-TR Reading Disorder
– Discrepancy between actual and expected reading achievement
– Reading is at a level significantly below that of a typical person of
the same age
– Problem cannot be caused by sensory deficits (e.g., poor vision)
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DSM-IV and DSM-IV-TR Mathematics Disorder
– Achievement below expected performance in mathematics
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DSM-IV and DSM-IV-TR Disorder of Written Expression
– Achievement below expected performance in writing
Learning Disorders: Some Facts and Statistics
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Incidence and Prevalence of Learning Disorders
– 1% to 3% incidence of learning disorders in the United States
– Prevalence is highest in wealthier regions of the United States
– Prevalence rate is 10% to 15% among school age children
– Reading difficulties are the most common of the learning disorders
– About 32% of students with learning disabilities drop out of school
– School experience for such persons tends to be quite negative
Biological and Psychosocial Causes of Learning Disorders
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Genetic and Neurobiological Contributions
– Reading disorder runs in families, with 100% concordance rate for
identical twins
– Evidence for subtle forms of brain damage is inconclusive
– Overall, genetic and neurobiological contributions are unclear
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Psychological and motivational factors seem to affect eventual outcome
Treatment of Learning Disorders
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Requires Intense Educational Interventions
– Remediation of basic processing problems (e.g., teaching visual
skills)
– Efforts to improve of cognitive skills (e.g., instruction in listening)
– Targeting behavioral skills to compensate for problem areas
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Data Support Behavioral Educational Interventions for Learning
Disorders
Pervasive Developmental Disorders: An Overview
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Nature of Pervasive Developmental Disorders
– Problems occur in language, socialization, and cognition
– Pervasive – Means the problems span the person’s entire life
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Examples of Pervasive Developmental Disorders
– Autistic disorder
– Asperger’s syndrome
Autistic Disorder
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Autism
– Significant impairment in social interactions and communication
– Restricted patterns of behavior, interest, and activities
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Three Central DSM-IV and DSM-IV-TR Features of Autism
– Problems in socialization and social function
– Problems in communication – 50% never acquire useful speech
– Restricted patterns of behavior, interests, and activities
Autistic Disorder: Facts and Statistics
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Prevalence and Features of Autism
– Affects 2 to 20 persons for every 10,000 people
– More prevalent in females with IQs below 35, and in males with
higher IQs
– Autism occurs worldwide
– Symptoms usually develop before 36 months of age
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Autism and Intellectual Functioning
– 50% have IQs in the severe-to-profound range of mental
retardation
– 25% test in the mild-to-moderate IQ range (i.e., IQ of 50 to 70)
– Remaining people display abilities in the borderline-to-average IQ
range
– Better language skills and IQ test performance predicts better
lifetime prognosis
Causes of Autism: Early and More Recent Contributions
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Historical Views
– Bad parenting
– Unusual speech patterns
– Lack of self-awareness
– Echolalia
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Current Understanding of Autism
– Medical conditions – Not always associated with autism
– Autism has a genetic component that is largely unclear
– Neurobiological evidence for brain damage – Link with mental
retardation
– Cerebellum size – Substantially reduced in persons with autism
Treatment of Pervasive Developmental Disorders
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Psychosocial “Behavioral” Treatments
– Skill building and treatment of problem behaviors
– Communication and language problems
– Address socialization deficits
– Early intervention is critical
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Biological and Medical Treatments Are Unavailable
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Integrated Treatments: The Preferred Model
– Focus on children, their families, parents, schools, and the home
– Build in appropriate community and social support
Mental Retardation (MR)
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Nature of Mental Retardation
– Disorder of childhood
– Below-average intellectual and adaptive functioning
– Range of impairment varies greatly across persons
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Mental Retardation and the DSM-IV and DSM-IV-TR
– Significantly subaverage intellectual functioning (IQ below 70)
– Concurrent deficits or impairments two or more areas of adaptive
functioning
– MR must be evident before the person is 18 years of age
DSM-IV and DSM-IV-TR Levels of Mental Retardation (MR)
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Mild MR
– Includes persons with an IQ score between 50 or 55 and 70
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Moderate MR
– Includes persons in the IQ range of 35-40 to 50-55
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Severe MR
– Includes people with IQs ranging from 20-25 up to 35-40
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Profound MR
– Includes people with IQ scores below 20-25
Other Classification Systems for Mental Retardation (MR)
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American Association of Mental Retardation (AAMR)
– Defines MR based on levels of assistance required
– Examples of levels include intermittent, limited, extensive, or
pervasive assistance
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Classification of MR in Educational Systems
– Educable mental retardation (i.e., IQ of 50 to approximately 70-75)
– Trainable mental retardation (i.e., IQ of 30 to 50)
– Severe mental retardation (i.e., IQ below 30)
Mental Retardation (MR): Some Facts and Statistics
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Prevalence
– About 1% to 3% of the general population
– 90% of MR persons are labeled with mild mental retardation
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Gender Differences
– MR occurs more often in males, male-to-female ratio of about 1.6:1
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Course of MR
– Tends to be chronic, but prognosis varies greatly from person to
person
Mental Retardation (MR): Biological Contributions
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Genetic Research
– MR involves multiple genes, and at times single genes
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Chromosomal Abnormalities and Other Forms of MR
– Down syndrome – Trisomy 21
– Fragile X syndrome – Abnormality on X chromosome
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Maternal Age and Risk of Having a Down’s Baby
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Nearly 75% of cases cannot be attributed to any known biological
cause
Mental Retardation (MR): Psychosocial Contributions
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Cultural-Familial Retardation
– Believed to cause about 75% of MR cases and is the least
understood
– Associated with mild levels of retardation on IQ tests and good
adaptive skills
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Cultural-Familial Retardation: Difference vs. Developmental Views
– Difference view – Mild MR is a matter of degree and kind
– Developmental view – Mild MR reflects a slowing or delay of normal
development
Treatment of Mental Retardation (MR)
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Parallels Treatment of Pervasive Developmental Disorders
– Teach needed skills to foster productivity and independence
– Educational and behavioral management
– Living and self-care skills via task analysis
– Communication training – Often most challenging treatment target!
– Community and supportive interventions
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Persons with MR Can Benefit from Such Interventions
Summary of Developmental Disorders
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Developmental Psychopathology and Normal and Abnormal Development
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Attention Deficit Hyperactivity Disorder
– Deficits in inattention, hyperactivity, or impulsivity
– Disrupt academic and social functioning
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Learning Disorders
– All share deficits in performance below expectations for IQ and school
preparation
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Pervasive Developmental Disorder
– All share deficits in language, socialization, and cognition
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Mental Retardation
– Subaverage IQ, deficits in adaptive functioning, onset before age 18
– Prevention and Early Intervention Are Critical for Developmental Disorders
Cognitive Disorders: An Overview
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Perspectives on Cognitive Disorders
– Affect cognitive processes such as learning, memory, and consciousness
– Most develop later in life
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Three Classes of Cognitive Disorders
– Delirium – Often temporary confusion and disorientation
– Dementia – Degenerative condition marked by broad cognitive deterioration
– Amnestic disorders – Memory dysfunctions caused by disease, drugs, or
toxins
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Shifting DSM Perspectives
– From “organic” mental disorders to “cognitive” disorders
– Broad impairments in memory, attention, perception, and thinking
– Profound changes in behavior and personality
Delirium
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Nature of Delirium
– Central features – Impaired consciousness and cognition
– Impairments develop rapidly over several hours or days
– Examples include confusion, disorientation, attention, memory, and
language deficits
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Facts and Statistics
– Affects 10% to 30% of persons in acute care facilities
– Most prevalent in older adults, AIDS patients, and medical patients
– Full recovery often occurs within several weeks
Medical Conditions Related to Delirium
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Medical Conditions
– Drug intoxication, poisons, withdrawal from drugs
– Infections, head injury, and several forms of brain trauma
– Sleep deprivation, immobility, and excessive stress
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DSM-IV and DSM-IV Subtypes of Delirium
– Delirium due to a general medical condition
– Substance-induced delirium
– Delirium due to multiple etiologies
– Delirium not otherwise specified
Treatment and Prevention of Delirium
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Treatment
– Attention to precipitating medical problems
– Psychosocial interventions include reassurance, coping strategies
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Prevention
– Address proper medical care for illnesses
– Address proper use and adherence to therapeutic drugs
Dementia
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Nature of Dementia
– Gradual deterioration of brain functioning
– Affects judgment, memory, language, and advanced cognitive processes
– Dementia has many causes and may be reversible or irreversible
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Progression of Dementia: Initial Stages
– Memory impairment, visuospatial skills deficits
– Agnosia – Inability to recognize and name objects (most common symptom)
– Facial agnosia – Inability to recognize familiar faces
– Other symptoms – Delusions, depression, agitation, aggression, and apathy
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Progression of Dementia: Later Stages
– Cognitive functioning continues to deteriorate
– Person requires almost total support to carry out day-to-day activities
– Death results from inactivity combined with onset of other illnesses
Dementia: Facts and Statistics
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Onset and Prevalence
– Can occur at any age, but most common in the elderly
– Affects 1% of those between 65-74 years of age
– Affects over 10% of persons 85 years and older
– 47% of adults over the age of 85 have dementia of the Alzheimer’s
type
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Incidence of Dementia
– Affects 2.3% of those 75-79 years of age and 8.5% of persons 85
and older
– Rates of new cases appear to double with every 5 years of age
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Gender and Sociocultural Factors
– Dementia occurs equally in men and women
– Dementia occurs equally across educational level and social class
DSM-IV and DSM-IV-TR Classes of Dementia
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Dementia of the Alzheimer’s type
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Vascular Dementia
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Dementia Due to Other General Medical Conditions
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Substance-Induced Persisting Dementia
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Dementia Due to Multiple Etiologies
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Dementia Not Otherwise Specified
Dementia of the Alzheimer’s Type
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DSM-IV-TR Criteria and Clinical Features
– Multiple cognitive deficits that develop gradually and steadily
– Predominant impairment in memory, orientation, judgment, and
reasoning
– Can include agitation, confusion, depression, anxiety, or
combativeness
– Symptoms are usually more pronounced at the end of the day
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Range of Cognitive Deficits
– Aphasia – Difficulty with language
– Apraxia – Impaired motor functioning
– Agnosia – Failure to recognize objects
– Difficulties with planning, organizing, sequencing, or abstracting
information
– Impairments have a marked negative impact on social and
occupational functioning
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An Autopsy Is Required for a Definitive Diagnosis
Alzheimer’s Disease: Some Facts and Statistics
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Nature and Progression of the Disease
– Deterioration is slow during the early and later stages, but rapid
during middle stages
– Average survival time is about 8 years
– Onset usually occurs in the 60s or 70s, but may occur earlier
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Prevalence of Alzheimer’s Disease
– Affects about 4 million Americans and many more worldwide
– Prevalence is greater in poorly educated persons and women
– Prevalence rates are low in some ethnic groups (e.g., Japanese,
Nigerian, Amish)
Vascular Dementia
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Nature of Vascular Dementia
– Progressive brain disorder caused by blockage or damage to blood
vessels
– Second leading cause of dementia next to Alzheimer’s
– Onset is often sudden (e.g., stroke)
– Patterns of impairment are variable, and most require formal care in
later stages
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DSM-IV and DSM-IV Criteria and Incidence
– Cognitive disturbances are identical to dementia
– Unlike Alzheimer’s, obvious neurological signs of brain tissue
damage occur
– Incidence is believed to be about 4.7% or men and 3.8% of women
Dementia Due to HIV Disease
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Overview and Clinical Features
– HIV causes neurological impairments and dementia
– Cognitive slowness, impaired attention, forgetfulness, and
clumsiness
– Repetitive movements (e.g., tremors/leg weakness), apathy, and
social withdrawal
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Progression of HIV-Related Cognitive Impairments
– Tend to occur during the later stages of HIV infection
– Impairments are observed in 29% to 87% of people with AIDS
– Subcortical dementia – Refers to deficits that affect inner brain
regions
– Aphasia is uncommon in subcortical dementia, but anxiety and
depression occur
Other Causes of Dementia: Head Trauma and Parkinson’s Disease
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Head Trauma
– Accidents are leading causes of such cognitive impairments
– Memory loss is the most common symptom
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Parkinson’s Disease
– Degenerative brain disorder
– Affects about 1 out of 1,000 people worldwide
– Motor problems are characteristic of this disorder
– Damage to dopamine pathways is believed to cause motor
problems
– Pattern of impairments are similar to subcortical dementia
Other Causes of Dementia: Huntington’s and Pick’s Disease
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Huntington’s Disease
– Genetic autosomal dominant disorder (i.e., chromosome 4)
– Manifests initially as chorea, usually later in life (around 40s or 50s)
– About 20% to 80% of persons go on to display dementia of the
subcortical pattern
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Pick’s Disease
– Rare neurological condition that produces a cortical dementia like
Alzheimer’s
– Also occurs later in life (around 40s or 50s)
– Little is known about what causes this disease
Other Dementias: Creutzfeldt-Jakob Disease and Substance-Induced
Dementia
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Creutzfeldt-Jakob Disease
– Affects 1 out of 1,000,000 persons
– Linked to mad cow disease
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Substance-Induced Persisting Dementia
– Results from drug use in combination with poor diet
– Examples include alcohol, inhalants, and sedative, hypnotic, and
anxiolytic drugs
– Resulting brain damage may be permanent
– Dementia is similar to that of Alzheimer’s
– Deficits may include aphasia, apraxia, agnosia, or disturbed
executive functioning
Causes of Dementia: The Example of Alzheimer’s Disease
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Early and Largely Unsupported Views: The Example of Smoking
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Current Neurobiological Findings
– Neurofibrillary tangles – Occur in all brains of Alzheimer’s patients
– Amyloid plaques – Accumulate excessively in brains of Alzheimer’s
patients
– Brains of Alzheimer’s patients tend to atrophy
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Current Neurobiological Findings
– Multiple genes are involved in Alzheimer’s disease (chromosomes
21, 19, 14, 12, 1)
– Chromosome 14 – Associated with early onset Alzheimer’s
– Chromosome 19 – Associated with a late onset Alzheimer’s
The Contributions of Psychosocial Factors in Dementia
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Do not cause dementia directly, but may influence onset and course
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Lifestyle factors – Drug use, diet, exercise, stress
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Cultural factors – Risk for certain diseases and accidents vary by
ethnicity and class
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Psychosocial factors – Educational attainment, coping skills, social
support
Medical and Psychosocial Treatment of Dementia
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Medical Treatment: Best if Enacted Early
– Few medical treatments exist for most types of dementia
– Most medical treatments attempt to slow progression of
deterioration
– Examples include glial cell-derived neurotrophic factor, Cognex,
vitamin E, aspirin
– Medical treatments do not stop progression of dementia
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Psychosocial Treatments
– Focus on enhancing the lives of dementia patients and their
families/caregivers
– Teach adaptive skills
– Use memory enhancement prosthetic devices (e.g., memory wallet)
– Main emphasis of psychosocial interventions appears to be on the
caregivers
Prevention of Dementia
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Reducing Risk of Dementia in Older Adults Via
– Estrogen-replacement therapy – Reduces risk of Alzheimer’s
dementia in women
– Proper treatment of cardiovascular diseases
– Use of anti-inflammatory medications
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Other Targets of Prevention Efforts
– Increasing safety behaviors to reduce head trauma
– Reducing exposure to neurotoxins and use of drugs
Amnestic Disorder
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Nature of Amnestic Disorder
– Inability to transfer information from short-term memory into longterm memory
– Often results from medical conditions, head trauma, or long-term
drug use
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DSM-IV and DSM-IV-TR Criteria for Amnestic Disorder
– Cover the inability to learn new information
– Inability to recall previously learned information
– Memory disturbance causes significant impairment in functioning
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The Example of Wernicke-Korsakoff Syndrome
– Caused by thalamic damage resulting from stroke or chronic heavy
alcohol use
– Attempt to restore thiamine deficiency in the case of chronic alcohol
abuse
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Research on Amnestic Disorders Is Scant