Neurodevelopmental Disorders
Overview of Neurodevelopmental Disorders
Neurodevelopmental disorders are a new combination of disorders in the DSM-5.
Considers the concept of what is normal versus abnormal.
Psychopathology.
Focuses on the developmental impact of early skill impairments.
Developmental Disorders
Typically first diagnosed in infancy, childhood, or adolescence.
Includes:
Attention Deficit Hyperactivity Disorder (ADHD).
Specific Learning Disorders.
Autism Spectrum Disorder.
Intellectual Disability.
Attention Deficit/Hyperactivity Disorder (ADHD)
Central Features:
Inattention.
Hyperactivity.
Impulsivity.
DSM-5 differentiates two symptom categories:
Problems of inattention.
Problems of hyperactivity and impulsivity.
Impairments:
Behavioral.
Cognitive.
Social.
Academic.
Diagnostic Criteria for ADHD (DSM-5)
A. A persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development, as characterized by (1) and/or (2):
1. Inattention: Six (or more) of the following symptoms have persisted for at least 6 months to a degree that is inconsistent with developmental level and negatively impacts social and academic/occupational activities.
Note: Symptoms are not solely a manifestation of oppositional behavior, defiance, hostility, or failure to understand tasks or instructions. For older adolescents and adults (age 17 and older), at least five symptoms are required.
a. Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or during other activities (e.g., overlooks or misses details, work is inaccurate).
b. Often has difficulty sustaining attention in tasks or play activities (e.g., has difficulty remaining focused during lectures, conversations, or lengthy reading).
c. Often does not seem to listen when spoken to directly (e.g., mind seems elsewhere, even in the absence of any obvious distraction).
d. Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., starts tasks but quickly loses focus and is easily sidetracked).
e. Often has difficulty organizing tasks and activities (e.g., difficulty managing sequential tasks; difficulty keeping materials and belongings in order; messy, disorganized, work; has poor time management; fails to meet deadlines).
f. Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (e.g., schoolwork or homework; for older adolescents and adults, preparing reports, completing forms, reviewing lengthy papers).
g. Often loses things necessary for tasks or activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, or mobile telephones).
h. Is often easily distracted by extraneous stimuli (for older adolescents and adults, may include unrelated thoughts).
i. Is often forgetful in daily activities (e.g., chores, running errands; for older adolescents and adults, returning calls, paying bills, keeping appointments).
2. Hyperactivity and impulsivity: Six (or more) of the following symptoms have persisted for at least 6 months to a degree that is inconsistent with developmental level and negatively impacts social and academic/occupational activities.
Note: The symptoms are not solely a manifestation of oppositional behavior, defiance, hostility, or failure to understand tasks or instructions. For older adolescents and adults (age 17 and older), at least five symptoms are required.
a. Often fidgets with or taps hands or feet or squirms in seat.
b. Often leaves seat in situations when remaining seated is expected (e.g., leaves his or her place in the classroom, in the office or other workplace, or in other situations that require remaining in place).
c. Often runs about or climbs in situations where it is inappropriate. (Note: In adolescents or adults, may be limited to feeling restless.)
d. Often unable to play or engage in leisure activities quietly.
e. Is often "on the go," acting as if "driven by a motor" (e.g., is unable to be or uncomfortable being still for an extended time, as in restaurants, meetings; may be experienced by others as being restless or difficult to keep up with).
f. Often talks excessively.
g. Often blurts out an answer before a question has been completed (e.g., completes people's sentences; cannot wait for turn in conversation).
h. Often has difficulty waiting his or her turn (e.g., while waiting in line).
i. Often interrupts or intrudes on others (e.g., butts into conversations, games, or activities; may start using other people's things without asking or receiving permission; for adolescents or adults, may intrude into or take over what others are doing).
B. Several inattentive or hyperactive-impulsive symptoms were present prior to age 12 years.
C. Several inattentive or hyperactive-impulsive symptoms are present in two or more settings (e.g., at home, school or work; with friends or relatives; in other activities).
D. There is clear evidence that the symptoms interfere with, or reduce the quality of, social, academic, or occupational functioning.
E. The symptoms do not occur exclusively during the course of schizophrenia or another psychotic disorder and are not better explained by another mental disorder (e.g., mood disorder, anxiety disorder, dissociative disorder, personality disorder, substance intoxication or withdrawal).
Specify whether:
Combined presentation: If both Criterion A1 (inattention) and Criterion A2 (hyperactivity-impulsivity) are met for the past 6 months.
Predominantly inattentive presentation: If Criterion A1 (inattention) is met but Criterion A2 (hyperactivity-impulsivity) is not met for the past 6 months.
Predominantly hyperactive/impulsive presentation: If Criterion A2 (hyperactivity-impulsivity) is met and Criterion A1 (inattention) is not met for the past 6 months.
ADHD: Statistics
Prevalence:
3% to 9% worldwide.
11% of children in the U.S. aged 4 to 17.
Onset: typically around 3 or 4 years.
Gender ratio: Boys : Girls = 3:1.
Possible cultural construct influencing diagnosis.
ADHD: Statistics (Adults)
Lower level jobs.
2.5 fewer years of education.
More likely to be divorced.
Higher rates of:
Substance use problems.
Antisocial personality disorder.
High-risk behaviors.
High comorbidity with:
Oppositional Defiant Disorder (ODD).
Mood disorders.
ADHD: Causes
Genetics:
Familial component.
Copy number variants (CNVs).
Dopamine genes:
DRD4.
DAT1.
DRD5 genes and their relation to Ritalin.
Norepinephrine.
GABA.
Serotonin.
ADHD: Causes (Neurobiological)
Smaller brain volume (3-4% smaller).
Role of toxins:
Allergens and food additives: no conclusive evidence.
Maternal smoking: increases risk, interacts with genetic predisposition.
ADHD: Causes (Psychosocial)
Negative responses from:
Teachers.
Peers.
Adults.
Peer rejection.
Low self-esteem.
Poor self-image.
Treatment of ADHD
Two fronts:
Psychosocial intervention.
Biological intervention.
Psychosocial Intervention Goals
Improving academic performance.
Decreasing disruptive behavior.
Improving social skills.
Behavioral interventions (parent training, social skills training) often implemented before medication.
Biological Intervention Goals
Reduce impulsivity and hyperactivity.
Improve attention.
Stimulants:
Ritalin (4 million currently treated).
Adderall.
Strattera.
Tenex.
Clonidine.
Effects of Medications
Improve compliance.
Decrease negative behaviors.
Do not directly affect learning and academic performance.
Possible abuse issues.
Side effects.
Psychopharmacogenetics: study of how genetic makeup influences response to drugs.
Combined Treatments
Behavioral and medication.
Often recommended.
Superior to individual treatments, but controversy exists.
Specific Learning Disorders
Performance substantially below expected levels based on:
Age.
IQ.
Education.
Focus on actual vs. expected achievement.
"Unexpected underachievement."
Not due to sensory deficits.
Combined under DSM-5:
Reading Disorder.
Mathematics Disorder.
Written Expression.
Response to intervention is a key factor.
Diagnostic Criteria for Specific Learning Disorder (DSM-5)
A. Difficulty learning and using academic skills, as indicated by the presence of at least one of the following symptoms that have persisted for at least 6 months, despite the provision of interventions that target those difficulties:
1. Inaccurate or slow and effortful word reading (e.g., reads single words aloud incorrectly or slowly and hesitantly, frequently guesses words, has difficulty sounding out words).
2. Difficulty understanding the meaning of what is read (e.g., may read text accurately but not understand the sequence, relationships, inferences, or deeper meanings of what is read).
3. Difficulties with spelling (e.g., may add, omit, or substitute vowels or consonants).
4. Difficulties with written expression (e.g., makes multiple grammatical or punctuation errors within sentences; employs poor paragraph organization, written expression of ideas lacks clarity).
5. Difficulties mastering number sense, number facts, or calculation (e.g., has poor understanding of numbers, their magnitude, and relationships; counts on fingers to add single-digit numbers instead of recalling the math fact as peers do; gets lost in the midst of arithmetic computation and may switch procedures).
6. Difficulties with mathematical reasoning (e.g., has severe difficulty applying mathematical concepts, facts, or procedures to solve quantitative problems).
B. The affected academic skills are substantially and quantifiably below those expected for the individual's chronological age and cause significant interference with academic or occupational performance, or with activities of daily living, as confirmed by individually administered standardized achievement measures and comprehensive clinical assessment. For individuals age 17 years and older, a documented history of impairing learning difficulties may be substituted for the standardized assessment.
C. The learning difficulties begin during school-age years but may not become fully manifest until the demands for those affected academic skills exceed the individual's limited capacities (e.g., as in timed tests, reading or writing lengthy complex reports for a tight deadline, excessively heavy academic loads).
D. The learning difficulties are not better accounted for by intellectual disabilities, uncorrected visual or auditory acuity, other mental or neurological disorders, psychosocial adversity, lack of proficiency in the language of academic instruction, or inadequate educational instruction.
Specify if:
With impairment in reading:
Word reading accuracy.
Reading rate or fluency.
Reading comprehension.
With impairment in written expression:
Spelling accuracy.
Grammar and punctuation accuracy.
Clarity or organization of written expression.
With impairment in mathematics:
Number Sense.
Memorization of arithmetic facts.
Accurate or fluent calculation.
Accurate math reasoning.
Specific Learning Disorders: Statistics
Prevalence: 6.5 million.
1% Caucasian.
2.6% African American.
4-10% for reading difficulties.
1% mathematics disorder.
Boys : Girls = 1:1.
Specific Learning Disorders: Statistics (Outcomes)
Students with learning disorders are more likely:
To have higher drop-out rates.
To be unemployed.
To have suicidal thoughts.
To have negative school experiences.
Possibly related to communication disorders.
Specific Learning Disorders: Causes
Genetic and neurobiological contributions:
Familial component.
Multiple gene influences.
Genes located on chromosomes 1, 2, 3, 6, 11, 12, 15, and 18.
Subtle brain impairment: structural and functional differences.
Specific Learning Disorders: Causes (Communication)
Communication disorders:
Childhood-onset fluency disorder – stuttering.
Language disorder.
Disorders of reading have been diagnosed more often in English-speaking countries.
Word recognition – dyslexia.
Comprehension.
Specific Learning Disorders: Causes (Psychosocial)
Motivational factors.
Socioeconomic status.
Cultural expectations.
Parental interactions.
Expectancies.
Child management practices.
Treatment of Specific Learning Disorders
Educational interventions:
Specific skills instructions:
Vocabulary.
Discerning meaning.
Fact-finding.
Strategy instruction:
Decision making.
Critical thinking.
Compensatory skills.
Treatment of Specific Learning Disorders (Biological & Direct Instruction)
Biological (drug) treatment is typically restricted to individuals who may also have comorbid ADHD.
Direct instruction:
Systematic instruction.
Teaching for mastery.
Behavioral interventions can change the way the brain works.
Autism Spectrum Disorder
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects how one perceives and socializes with others.
DSM-5 combined the following into Autism spectrum disorder (ASD):
Autistic disorder.
Asperger’s disorder.
Childhood disintegrative disorder.
Rett disorder is now diagnosed as ASD with a qualifier.
Pervasive developmental disorder “Not otherwise specified” dropped in DSM-5.
Social (Pragmatic) Communication Disorder was added to the DSM-5.
Autism Spectrum Disorder: Characteristics
Two major characteristics of ASD:
Communication and social interaction.
Restricted, repetitive patterns of behavior, interests, or activities.
Three levels of severity:
Level 1— "Requiring support".
Level 2— "Requiring substantial support".
Level 3— "Requiring very substantial support".
Described qualitatively and, as yet, has no quantitative equivalent.
Diagnostic Criteria for Autism Spectrum Disorder (DSM-5)
A. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history (examples are illustrative, not exhaustive):
1. Deficits in social-emotional reciprocity; ranging, for examplefrom abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, and affect; to failure to initiate or respond to social interactions.
2. Deficits in nonverbal communicative behaviors used for social interaction, ranging for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.
3. Deficits in developing, maintaining and understanding relationships, ranging for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play and in making friends; to absence of interest in peers.
B. Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following, currently or by history (examples are illustrative, not exhaustive):
1. Stereotyped or repetitive motor movements, use of objects or, speech; (e.g., simple motor stereotypies, lining up toys or flipping objects, echolalia, idiosyncratic phrases).
2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat same food every day).
3. Highly restricted, fixated interests that are abnormal in intensity or focus (e.g., strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).
4. Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement).
C. Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies in later life).
D. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.
E. The disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level.
Autism Spectrum Disorder: Social Communication and Interaction
Impairment in social communication and social interaction.
Fail to develop age-appropriate social relationships.
Deficits in nonverbal communication.
Social communication and social interaction issues include lack of joint attention and impaired prosody.
25% never acquire speech, may exhibit echolalia and conversational impairments.
Autism Spectrum Disorder: Repetitive Patterns
Restricted, repetitive patterns of behavior, interests, or activities.
Maintenance of sameness.
Stereotyped and ritualistic behaviors.
Autism Spectrum Disorder : Statistics
Prevalence: 1 in every 50 births.
Male to female ratio is estimated to be 4.4 to 1.
IQ interaction: 38% have intellectual disabilities.
Occurs worldwide.
Causes of Autism Spectrum Disorder : Psychological and Social Dimensions
Historical views:
Failed parenting (perfectionistic, cold, and aloof).
High socioeconomic status and higher IQs were thought to be factors.
Lack of self-awareness and limited self-concept.
Behavioral correlates: echolalia and self-injury.
Causes of Autism Spectrum Disorder : Biological
Significant genetic component:
Familial component with a 20% risk of a second child with autism (100-fold increase in risk).
Numerous genes on a number of chromosomes involved.
Oxytocin receptor genes play a role in bonding and social memory.
Older parents increase the risk.
Causes of Autism Spectrum Disorder : Biological (Neurobiological)
Amygdala:
Larger size at birth correlates with higher anxiety and fear.
Elevated cortisol levels and neuronal damage.
Similar size when older but with fewer neurons.
Oxytocin:
Lower levels.
Vaccinations:
No increased risk; the negative effect of not vaccinating outweighs any perceived risk.
Treatment of Autism Spectrum Disorder
Psychosocial treatments:
Behavioral approaches:
Skill building.
Reduce problem behaviors.
Communication and language training.
Increase socialization.
Naturalistic teaching strategies implemented with early intervention being critical.
Biological treatments:
Medical intervention has had little positive impact.
Some medications can decrease agitation, such as tranquilizers and SSRIs.
Integrated treatments:
Preferred model including a multidimensional, comprehensive focus on children, families, schools, home, and community/social support.
Intellectual Disability (Intellectual Developmental Disorder)
Intellectual disability (ID) is a disorder evident in childhood as significantly below-average intellectual and adaptive functioning.
DSM-5 identifies difficulties in three domains:
Conceptual (e.g., skill deficits in areas such as language, reasoning, knowledge, and memory).
Social (e.g., problems with social judgment and the ability to make and retain friendships).
Practical (e.g., difficulties managing personal care or job responsibilities).
Individuals are often devalued by society.
Intellectual Disability (Intellectual Developmental Disorder): Clinical Description
Former axis II DSM-IV.
Below-average intellectual functioning measured by standardized tests, with an IQ of 70-75 or below (2% of the general population, representing a statistical decision of 2 SD from the mean).
Adaptive problems in:
Communication.
Self-care.
Home living.
Social and interpersonal skills.
Use of community resources.
Self-direction.
Functional academic skills.
Work.
Leisure.
Health and safety.
Diagnostic Criteria for Intellectual Disability (DSM-5)
Intellectual disability (intellectual developmental disorder) is a disorder with onset during the developmental period that includes both intellectual and adaptive functioning deficits in conceptual, social, and practical domains.
The following three criteria must be met:
A. Deficits in intellectual functions, such as reasoning, problem-solving, planning, abstract thinking, judgment, academic learning, and learning from experience, confirmed by both clinical assessment and individualized, standardized intelligence testing.
B. Deficits in adaptive functioning that result in failure to meet developmental and sociocultural standards for personal independence and social responsibility. Without ongoing support, the adaptive deficits limit functioning in one or more activities of daily life, such as communication, social participation, and independent living, across multiple environments such as home, school, work, and community.
C. Onset of intellectual and adaptive deficits during the developmental period (before age 18).
Levels of Intellectual Disability
Mild: IQ = 50 or 55 to 70.
Moderate: IQ = 35-40 to 50-55.
Severe: IQs = 20-25 to 35-40.
Profound: IQ = below 20-25.
Other Classification Systems for Intellectual Disability
American Association of Intellectual and Developmental Disabilities (AAIDD) based on assistance required:
Intermittent.
Limited.
Extensive.
Pervasive.
Intellectual Disability (Intellectual Developmental Disorder): Statistics
Prevalence = 2% with 99% being mild.
Chronic course with highly variable individual prognosis.
Causes of Intellectual Disability (Intellectual Developmental Disorder)
Hundreds of known causes, including environmental, prenatal, perinatal, and postnatal factors.
Prenatal factors include fetal alcohol syndrome, disease, chemicals, poor nutrition, and lack of oxygen (anoxia) during birth.
Causes of Intellectual Disability (Genetic)
Genetic influences:
Multiple genes, chromosomal disorders, mitochondrial disorders, multiple genetic mutations, and single genes (dominant and recessive).
Most cases of ID have no identified etiology.
De novo disorders like tuberous sclerosis, phenylketonuria (PKU), and Lesch-Nyham syndrome which is X-linked (males).
Causes of Intellectual Disability (Chromosomal)
Chromosomal influences:
Down syndrome (formerly mongoloidism) due to an extra 21st chromosome (Trisomy 21).
Physical symptoms include upwardly slanting eyes, a flat nose, and a small mouth with a flat roof that makes the tongue protrude somewhat.
Increased prevalence of Alzheimer’s.
Risk increases with maternal age.
Prenatal screening/testing options such as amniocentesis, chorionic villus sampling (CVS), and mothers blood tests can be used. Elective abortion rates average about 25%.
Causes of Intellectual Disability (Fragile X Syndrome)
Fragile X syndrome primarily affects males.
Women who carry fragile X syndrome may exhibit learning disabilities, hyperactivity, and short attention spans as well as gaze avoidance and perseverative speech.
Physical characteristics include large ears, large testicles, and a large head circumference.
Cultural-familial intellectual disability due to abuse, neglect, and social deprivation.
Treatment of Intellectual Disability (Intellectual Developmental Disorder)
Treatment for ID parallels that of people with more severe forms of autism spectrum disorder.
For mild ID, intervention is similar to that for people with learning disorders.
For people with more severe disabilities, the general goals are the same; however, the level of assistance they need is often more extensive.
Common goal for all levels of ID is participation in community life, attending school and later holding a job, and the opportunity for meaningful social relationships.
Behavioral innovations can help teach skills ranging from basic self-care (dressing, bathing, feeding, toileting) to people.
Prevention of Neurodevelopmental Disorders
Early intervention for at-risk children and families through programs like Head Start, which provides educational, medical, and social supports.
Genetic screening for detection and correction, including prenatal gene therapy.