developmental disorders.ppt

Developmental and Developmental and Cognitive DisordersCognitive Disorders

Chapter 13Chapter 13

What are developmental What are developmental disorders?disorders?

Disorders that usually first appear in Disorders that usually first appear in childhood or adolescence (onset)childhood or adolescence (onset)

Note: most of these conditions persist Note: most of these conditions persist into adulthoodinto adulthood

In te llectu a l & C o g n itve im p airm ent-a ll M R-a ll L D

M o to r F un ctio n im p a irm enta ll m o to r sk ills d /o

a ll t ic d /os te reo typ ic m o ve m en t d /o

D isru ptive or se lf in ju rio u s beh av io ra ll a d hd & d is ru p tive d /o

fe e d in g & ea tin g d /oa ll e lim n a tion d /o , se p e ra tio n an x ie ty

In fo rm atio n exch an gea ll p e rva s ive d /o

a ll com m un ica tio n d /ose le c tive m u tism

IC A d iso rd ers

ICA D/OICA D/O As you answer the questions below, you As you answer the questions below, you

will be better able to choose between the will be better able to choose between the four categories introduced earlier.four categories introduced earlier. 1. Is the predominant sx an impairment of 1. Is the predominant sx an impairment of

learning or intellectual function?learning or intellectual function? 2. Is the predominant sx abnormal motor 2. Is the predominant sx abnormal motor

activity?activity? 3. Is the predominant sx socially inappropriate 3. Is the predominant sx socially inappropriate

or self injurious behavior?or self injurious behavior? 4. Is the predominant sx an impairment in the 4. Is the predominant sx an impairment in the

ability to communicate or exchange ability to communicate or exchange meaningful information?meaningful information?

Perspectives on Perspectives on Developmental DisordersDevelopmental Disorders

Normal vs. Abnormal DevelopmentNormal vs. Abnormal Development Developmental PsychopathologyDevelopmental Psychopathology

Study of how disorders arise and Study of how disorders arise and change with timechange with time

Childhood is associated with significant Childhood is associated with significant developmental changesdevelopmental changes

Disruption of early skills will likely Disruption of early skills will likely disrupt development of later skillsdisrupt development of later skills

OutlineOutline

CommonCommon developmental disorders developmental disorders (ADHD & Learning Disorders)(ADHD & Learning Disorders)

Pervasive Developmental disorders Pervasive Developmental disorders (autism)(autism)

Mental RetardationMental Retardation Cognitive Disorders (dementia)Cognitive Disorders (dementia)

Attention Deficit Hyperactivity Attention Deficit Hyperactivity Disorder (ADHD): An OverviewDisorder (ADHD): An Overview

Nature of ADHDNature of ADHD Central features – Inattention, overactivity, and Central features – Inattention, overactivity, and

impulsivityimpulsivity

Difficulty w sustained attn (can’t finish games, watch Difficulty w sustained attn (can’t finish games, watch TV)TV)

Constant motion, fidgetingConstant motion, fidgeting

Blurt out answers, act without thinkingBlurt out answers, act without thinking

Associated with behavioral, cognitive, social, Associated with behavioral, cognitive, social, and academic problemsand academic problems

Attention Deficit Hyperactivity Attention Deficit Hyperactivity Disorder (ADHD): An OverviewDisorder (ADHD): An Overview

DSM-IV and DSM-IV-TR Symptom DSM-IV and DSM-IV-TR Symptom ClustersClusters Cluster 1 – Symptoms of inattention Cluster 1 – Symptoms of inattention

Cluster 2 – Symptoms of hyperactivity Cluster 2 – Symptoms of hyperactivity and impulsivity clusterand impulsivity cluster

Either cluster 1 or 2 must be present for Either cluster 1 or 2 must be present for a diagnosisa diagnosis

ADHD: Facts and Statistics ADHD: Facts and Statistics PrevalencePrevalence

Occurs in 4%-12% of children who are 6 to 12 Occurs in 4%-12% of children who are 6 to 12 years of ageyears of age

Symptoms are usually present around age 3 or Symptoms are usually present around age 3 or 44

68% of children with ADHD have problems as 68% of children with ADHD have problems as adultsadults

Impulsive component decreases over timeImpulsive component decreases over time

Gender Differences Gender Differences Boys outnumber girls 4 to 1Boys outnumber girls 4 to 1

ADHD: Overdiagnosis?ADHD: Overdiagnosis?

Cultural Factors Cultural Factors Probability of ADHD diagnosis is Probability of ADHD diagnosis is

greatest in the United Statesgreatest in the United States Studies show more school-aged kids on Studies show more school-aged kids on

stimulants than prevalence of Dxstimulants than prevalence of Dx College-aged people often present for College-aged people often present for

assessment when academic problems assessment when academic problems emergeemerge

ADHD: Biological ADHD: Biological Contributions Contributions

Genetic ContributionsGenetic Contributions ADHD runs in familiesADHD runs in families Some studies suggest High heritabilitySome studies suggest High heritability Familial ADHD may involve deficits on Familial ADHD may involve deficits on

chromosome 20chromosome 20

The DThe D44 receptor gene is more common receptor gene is more common in ADHD children (dopamine in ADHD children (dopamine dysregulation?)dysregulation?)


Neurobiological Contributions: Brain Neurobiological Contributions: Brain Dysfunction and Damage Dysfunction and Damage

Used to be called “minimal brain Used to be called “minimal brain dysfunction”dysfunction” Inactivity of the frontal cortex and basal gangliaInactivity of the frontal cortex and basal ganglia

Right hemisphere malfunctionRight hemisphere malfunction

Abnormal frontal lobe development and Abnormal frontal lobe development and functioningfunctioning

Yet to identify a precise neurobiological Yet to identify a precise neurobiological mechanism for ADHDmechanism for ADHD


The Role of ToxinsThe Role of Toxins Allergens and food additives do not Allergens and food additives do not

appear to cause ADHDappear to cause ADHD Maternal smoking increases risk of Maternal smoking increases risk of

having a child with ADHDhaving a child with ADHD

ADHD: Psychosocial ADHD: Psychosocial ContributionsContributions

Psychosocial Factors appear to Psychosocial Factors appear to Influence (not cause) the DisorderInfluence (not cause) the Disorder Constant negative feedback from Constant negative feedback from

teachers, parents, and peersteachers, parents, and peers

Peer rejection and resulting social Peer rejection and resulting social isolationisolation

Such factors foster low self-image Such factors foster low self-image

Biological Treatment of ADHDBiological Treatment of ADHD Goal of Biological TreatmentsGoal of Biological Treatments

To reduce impulsivity/hyperactivity and to To reduce impulsivity/hyperactivity and to improve attentionimprove attention

Stimulant MedicationsStimulant Medications Reduce the core symptoms of ADHD in 70% of Reduce the core symptoms of ADHD in 70% of

casescases

Examples include Ritalin, Dexedrine, CylertExamples include Ritalin, Dexedrine, Cylert

Other MedicationsOther Medications Imipramine and Clonidine (antihypertensive) Imipramine and Clonidine (antihypertensive)

have some efficacyhave some efficacy

Biological Treatment of ADHDBiological Treatment of ADHD

Effects of MedicationsEffects of Medications Improve compliance and decrease negative Improve compliance and decrease negative

behaviors in many childrenbehaviors in many children

Not clear that academic performance or social Not clear that academic performance or social skills are improved in the long-termskills are improved in the long-term

Beneficial effects are not lasting following Beneficial effects are not lasting following drug discontinuationdrug discontinuation

Negative side effects include insomnia, Negative side effects include insomnia, drowsiness, and irritabilitydrowsiness, and irritability

Behavioral and Combined Behavioral and Combined Treatment of ADHDTreatment of ADHD

Behavioral TreatmentBehavioral Treatment Involve reinforcement programs Involve reinforcement programs

Aim to increase appropriate behaviors and Aim to increase appropriate behaviors and decrease inappropriate behaviorsdecrease inappropriate behaviors

May also involve parent trainingMay also involve parent training

Combined Bio-Psycho-Social TreatmentsCombined Bio-Psycho-Social Treatments Are highly recommended - it appears however Are highly recommended - it appears however

that long-term psychosocial Tx is necessary to that long-term psychosocial Tx is necessary to maintain gainsmaintain gains

Learning DisordersLearning Disorders Scope of Learning Disorders Scope of Learning Disorders

Problems related to academic performance in Problems related to academic performance in reading, mathematics, and writingreading, mathematics, and writing

Performance is substantially below what would Performance is substantially below what would be expected (IQ - Ach discrepancy) be expected (IQ - Ach discrepancy)

DSM-IV and DSM-IV-TR Reading, DSM-IV and DSM-IV-TR Reading, Mathematics, Written Expression DisordersMathematics, Written Expression Disorders Performance is at a level significantly below Performance is at a level significantly below

that of a typical person of the same agethat of a typical person of the same age

Problem cannot be caused by sensory deficits Problem cannot be caused by sensory deficits (e.g., poor vision)(e.g., poor vision)

Learning Disorders: Some Learning Disorders: Some Facts and StatisticsFacts and Statistics Incidence and Prevalence of Learning Incidence and Prevalence of Learning

DisordersDisorders 1% to 3% incidence of learning disorders in the United States1% to 3% incidence of learning disorders in the United States

Prevalence is highest in wealthier regions of the United StatesPrevalence is highest in wealthier regions of the United States

Prevalence rate is 10% to 15% among school age childrenPrevalence rate is 10% to 15% among school age children

Reading difficulties are the most common of the learning Reading difficulties are the most common of the learning disordersdisorders

School experience for such persons tends to be quite negativeSchool experience for such persons tends to be quite negative

About 32% of students with learning disabilities drop out of About 32% of students with learning disabilities drop out of schoolschool

FigurFigure 13.1e 13.1

Half of school children classified as Half of school children classified as disabled have learning disabilities. disabled have learning disabilities.

Twenty years ago the proportion was Twenty years ago the proportion was 50% lower50% lower

Biological and Psychosocial Biological and Psychosocial Causes of Learning DisordersCauses of Learning Disorders

Genetic and Neurobiological ContributionsGenetic and Neurobiological Contributions Reading disorder runs in families, with 100% Reading disorder runs in families, with 100%

concordance rate for identical twinsconcordance rate for identical twins

Evidence for subtle forms of brain damage is Evidence for subtle forms of brain damage is inconclusiveinconclusive

Overall, genetic and neurobiological Overall, genetic and neurobiological contributions are unclear contributions are unclear

Psychological and motivational factors Psychological and motivational factors seem to affect eventual outcomeseem to affect eventual outcome

Treatment of Learning Treatment of Learning DisordersDisorders

Medications not typically usedMedications not typically used

Requires Intense Educational InterventionsRequires Intense Educational Interventions Remediation of basic processing problems (e.g., Remediation of basic processing problems (e.g.,

teaching visual skills)teaching visual skills)

Efforts to improve of cognitive skills (e.g., Efforts to improve of cognitive skills (e.g., instruction in listening)instruction in listening)

Targeting behavioral skills to compensate for Targeting behavioral skills to compensate for problem areasproblem areas

Data Support Behavioral Educational Data Support Behavioral Educational Interventions for Learning DisordersInterventions for Learning Disorders

Pervasive Developmental Pervasive Developmental DisordersDisorders

PDD is an umbrella termPDD is an umbrella term severe and pervasive impairments in severe and pervasive impairments in

several areas of development: reciprocal several areas of development: reciprocal social interaction skills, communication social interaction skills, communication skills, presence of stereotyped behavior, skills, presence of stereotyped behavior, interests, and activitiesinterests, and activities

Symptoms are on a continuumSymptoms are on a continuum 5 PDD’s: autistic disorder, Asperger’s 5 PDD’s: autistic disorder, Asperger’s

disorder, Rett’s disorder, Childhood disorder, Rett’s disorder, Childhood Disintegrative Disorder, PDD/NOS Disintegrative Disorder, PDD/NOS (distinctions among these not particularly clear)(distinctions among these not particularly clear)

Autistic DisorderAutistic Disorder Approximately 10 cases per 10,000 Approximately 10 cases per 10,000

individualsindividuals More common in males (4-5:1)More common in males (4-5:1) Impairment in Social InteractionsImpairment in Social Interactions Impairment in CommunicationImpairment in Communication Restricted, Repetitive and Restricted, Repetitive and

Stereotyped Behaviors, Interests, Stereotyped Behaviors, Interests, and Activitiesand Activities

Onset of delays prior to age 3 yearsOnset of delays prior to age 3 years

Autistic Disorder (cont.)Autistic Disorder (cont.)

QQualitative Impairment in Social Interaction ualitative Impairment in Social Interaction (needs at least 2)(needs at least 2)

marked impairment in the use of nonverbal marked impairment in the use of nonverbal behaviorsbehaviors

Failure to develop peer relationships Failure to develop peer relationships appropriate to developmental levelappropriate to developmental level

A lack of spontaneous seeking to share A lack of spontaneous seeking to share enjoyment, interests, or achievementsenjoyment, interests, or achievements

lack of social or emotional reciprocitylack of social or emotional reciprocity

Autistic Disorder (cont.)Autistic Disorder (cont.)Qualitative impairment in Communication (needs a Qualitative impairment in Communication (needs a lest one)lest one)

delay or total lack of development of spoken delay or total lack of development of spoken language (no compensation)language (no compensation)

marked impairment in the ability to initiate or marked impairment in the ability to initiate or sustain a conversation with others in individuals sustain a conversation with others in individuals that can speakthat can speak

stereotyped and repetitive use of language or stereotyped and repetitive use of language or idiosyncratic languageidiosyncratic language

lack of carried , spontaneous make-believe play or lack of carried , spontaneous make-believe play or social imitative play appropriate to developmental social imitative play appropriate to developmental level. level.

Autistic Disorder (cont.)Autistic Disorder (cont.)Restricted, Repetitive and Stereotyped Restricted, Repetitive and Stereotyped Behaviors, Interests, and Activities (needs at Behaviors, Interests, and Activities (needs at least one)least one)

encompassing preoccupation with one or more encompassing preoccupation with one or more stereotyped and restricted patterns of interest stereotyped and restricted patterns of interest that is abnormal either in intensity or focusthat is abnormal either in intensity or focus

apparently inflexible adherence to specific, apparently inflexible adherence to specific, nonfunctional routines or ritualsnonfunctional routines or rituals

stereotyped mannerismsstereotyped mannerisms persistent preoccupation with parts of objectspersistent preoccupation with parts of objects

Other issues related to autismOther issues related to autism Sensory issues (e.g., high threshold Sensory issues (e.g., high threshold

for pain, oversensitivity to sounds, for pain, oversensitivity to sounds, fascination with touch or smell)fascination with touch or smell)

Abnormalities in mood and affectAbnormalities in mood and affect Feeding issues (limited diet, pica)Feeding issues (limited diet, pica) Behavior difficulties (SIB, Tantrums, Behavior difficulties (SIB, Tantrums,

short attention span, hyperactivity, short attention span, hyperactivity, sleep problems) sleep problems)

Phenomenology of AutismPhenomenology of Autism

20/20 Video20/20 Video What is it like to be autistic? What is it like to be autistic?

Autism and Intellectual Autism and Intellectual FunctioningFunctioning

75% of individuals have mental retardation75% of individuals have mental retardation

50% have IQs in the severe-to-profound range 50% have IQs in the severe-to-profound range of mental retardationof mental retardation

25% test in the mild-to-moderate IQ range (i.e., 25% test in the mild-to-moderate IQ range (i.e., IQ of 50 to 70)IQ of 50 to 70)

Remaining people display abilities in the Remaining people display abilities in the borderline-to-average IQ rangeborderline-to-average IQ range

Better language skills and IQ test performance Better language skills and IQ test performance predicts better lifetime prognosispredicts better lifetime prognosis

Etiology of AutismEtiology of Autism Psychosocial Contributions Are UnclearPsychosocial Contributions Are Unclear

Autism has a genetic component that is Autism has a genetic component that is largely unclearlargely unclear

Neurobiological evidence for brain Neurobiological evidence for brain damage – Link with mental retardation damage – Link with mental retardation Cerebellum size – Substantially reduced in Cerebellum size – Substantially reduced in

persons with autism persons with autism

Asperger’s DisorderAsperger’s Disorder Qualitative impairment in social Qualitative impairment in social

interactioninteraction Restrictive Repetitive and Restrictive Repetitive and

stereotyped patterns of behavior, stereotyped patterns of behavior, interest, and activitiesinterest, and activities

Disturbance causes clinically Disturbance causes clinically significant impairmentsignificant impairment

nono clinically significant general delay clinically significant general delay in languagein language

nono clinically significant delay in clinically significant delay in cognitive or adaptive functioningcognitive or adaptive functioning

Rett’s DisorderRett’s Disorder Only reported in femalesOnly reported in females Apparent normal pre and perinatal Apparent normal pre and perinatal

developmentdevelopment Normal head circumference at birthNormal head circumference at birth Deceleration of head growth between 5 and Deceleration of head growth between 5 and

48 months48 months Loss of hand skills between 5 and 30 months Loss of hand skills between 5 and 30 months

with development of stereotyped hand with development of stereotyped hand movement, loss of social engagement, poorly movement, loss of social engagement, poorly coordinated gait or trunk movements, coordinated gait or trunk movements, severely impaired expressive and receptive severely impaired expressive and receptive language development with severe language development with severe psychomotor retardationpsychomotor retardation

Severe or Profound MRSevere or Profound MR

Applied Behavior AnalysisApplied Behavior Analysis Breaks down autism into separate behavioral Breaks down autism into separate behavioral

problems and attempts to treat as many of problems and attempts to treat as many of these problems as possible. these problems as possible.

By far the most well documented treatment By far the most well documented treatment approach with hundreds of studies on approach with hundreds of studies on behavioral treatment for children with autism.behavioral treatment for children with autism.

Goal is remediation (recovery) from the Goal is remediation (recovery) from the disorder to the point that children are disorder to the point that children are indistinguishable from their peers.indistinguishable from their peers.

UCLA Young Autism Project (Lovaas)UCLA Young Autism Project (Lovaas) Intensive one-on-one training for app. 40 hours a Intensive one-on-one training for app. 40 hours a

week.week. Training prg carried out in homes, school, Training prg carried out in homes, school,

communitycommunity commences at age no older than 46 monthscommences at age no older than 46 months 1st phase, focuses on teaching compliance, simple 1st phase, focuses on teaching compliance, simple

imitation, appropriate play, suppress self-stimulation imitation, appropriate play, suppress self-stimulation and non-compliant behaviorand non-compliant behavior

2nd phase teaching expressive skills, early abstract 2nd phase teaching expressive skills, early abstract language, social play with peerslanguage, social play with peers

Third phase teaching expression of emotions, Third phase teaching expression of emotions, functional academics and more complex cognitive functional academics and more complex cognitive abilities (e.g., cause-to-effect relationships)abilities (e.g., cause-to-effect relationships)

UCLA Young Autism Project - study designUCLA Young Autism Project - study design

Initial 2 year treatment Initial 2 year treatment N = 59 children N = 59 children 3 groups: 3 groups:

(a) (a) Experimental groupExperimental group (N=19) - 40 hours a week (N=19) - 40 hours a week of treatment for 2 years of treatment for 2 years

Control group # 1Control group # 1 (N=19) - 10 hours of treatment (N=19) - 10 hours of treatment for 2 years on average for 2 years on average

Control group #2Control group #2 (N=21) - No treatment provided (N=21) - No treatment provided by UCLA by UCLA

Blind Evaluations pre & post treatmentBlind Evaluations pre & post treatment

UCLA Young Autism Project UCLA Young Autism Project pre-treatmentpre-treatment

Exp GroupExp Group Control Group Control Group # 1# 1

Treatment:Treatment: 40 hrs/week40 hrs/week 10 hrs/week 10 hrs/week

Pre Treatment Measures:Pre Treatment Measures:

Age at DxAge at Dx 32 months32 months 34 months34 months

Age @ Beg. trtAge @ Beg. trt 35 months35 months 40 months40 months

IQIQ 5353 4646

UCLA Young Autism Project UCLA Young Autism Project pre-treatmentpre-treatment

Exp GrExp Gr Control Group # 1Control Group # 1(N=19)(N=19) (N=19)(N=19)

MuteMute 58% 58% 47%47%Reject AdultsReject Adults 63% 63% 42%42%Not Toilet TrainedNot Toilet Trained 68% 68% 63%63%Gross InattentionGross Inattention 89% 89% 74%74%TantrumsTantrums 89% 89% 79%79%Absent Toy PlayAbsent Toy Play 53% 53% 63%63%Self StimulationSelf Stimulation 95% 95% 89%89%Absent Peer PlayAbsent Peer Play 100% 100% 100%100%

UCLA Young Autism Project- ResultsUCLA Young Autism Project- Results Blind evaluation: pre treatment & 2 years later (Age 6-7)Blind evaluation: pre treatment & 2 years later (Age 6-7)

Experimental Group ResultsExperimental Group Results:: ** ** Average IQ Gain = 20 pointsAverage IQ Gain = 20 points ** ** 9/19 (47%) Completed first grade in regular class 9/19 (47%) Completed first grade in regular class ** ** IQ Gain for these 9 subjects = 37 pointsIQ Gain for these 9 subjects = 37 points 8/19 (42%) Continued in a learning disabled class8/19 (42%) Continued in a learning disabled class 2/19 (11%) Severe MR / autistic classroom2/19 (11%) Severe MR / autistic classroom

Control Group ResultsControl Group Results: : Group # 1 Group # 2 Group # 1 Group # 2 IQ IQ no significant changesno significant changes Completed first grade in regular class: 0/19 ( 0%) 1/21 (5%)Completed first grade in regular class: 0/19 ( 0%) 1/21 (5%) Continued in a learning disabled class: 8/19 (42%) 10/21 Continued in a learning disabled class: 8/19 (42%) 10/21

(48%)(48%) Continued in a Severe MR Class: 11/19 (58%) 10/21 (48%)Continued in a Severe MR Class: 11/19 (58%) 10/21 (48%)

UCLA Young Autism Project- ResultsUCLA Young Autism Project- Results 1993 Follow Up Study Results1993 Follow Up Study Results

Blind Evaluations of the 9 children in the “Best Blind Evaluations of the 9 children in the “Best Outcome” GroupOutcome” Group Age at follow up evaluation - 13 years old.Age at follow up evaluation - 13 years old. IQ gains remained.IQ gains remained. Normal functioning on tests of:Normal functioning on tests of:

emotional functioning;emotional functioning; social functioning;social functioning; intellectual functioning.intellectual functioning.

8/9 (88%) Remained in typical classrooms.8/9 (88%) Remained in typical classrooms. 1/9 was in an LD classroom.1/9 was in an LD classroom.

Autism - PharmacotherapyAutism - Pharmacotherapy

No known effective medicationsNo known effective medications

Mental RetardationMental Retardation Nature of Mental RetardationNature of Mental Retardation

Disorder of childhoodDisorder of childhood

Below-average intellectual and adaptive functioningBelow-average intellectual and adaptive functioning

Range of impairment varies greatly across personsRange of impairment varies greatly across persons

Mental Retardation and the DSM-IV and DSM-IV-TRMental Retardation and the DSM-IV and DSM-IV-TR Significantly subaverage intellectual functioning (IQ Significantly subaverage intellectual functioning (IQ

below 70 - about 2-3% of the population)below 70 - about 2-3% of the population)

Concurrent deficitsConcurrent deficits or impairments two or more areas of or impairments two or more areas of adaptive functioningadaptive functioning

MR must be evident before the person is 18 years of ageMR must be evident before the person is 18 years of age

Levels of MRLevels of MR Mild MRMild MR

Includes persons with an IQ score between 50 or Includes persons with an IQ score between 50 or 55 and 70 (often can lead independent lives)55 and 70 (often can lead independent lives)

Moderate MRModerate MR Includes persons in the IQ range of 35-40 to 50-55Includes persons in the IQ range of 35-40 to 50-55

Severe MRSevere MR Includes people with IQs ranging from 20-25 up Includes people with IQs ranging from 20-25 up

to 35-40to 35-40

Profound MRProfound MR Includes people with IQ scores below 20-25 Includes people with IQ scores below 20-25

(typically require complete assistance)(typically require complete assistance)

Other Classification Systems Other Classification Systems for Mental Retardation (MR)for Mental Retardation (MR)

American Association of Mental Retardation (AAMR)American Association of Mental Retardation (AAMR) Defines MR based on levels of assistance requiredDefines MR based on levels of assistance required

Examples of levels include intermittent, limited, extensive, Examples of levels include intermittent, limited, extensive, or pervasive assistanceor pervasive assistance

Not that widely adoptedNot that widely adopted

Classification of MR in Educational SystemsClassification of MR in Educational Systems Based on whether person is “Educable”Based on whether person is “Educable”

Stigmatizing systemStigmatizing system

Mental Retardation (MR): Mental Retardation (MR): Some Facts and StatisticsSome Facts and Statistics

PrevalencePrevalence About 1% to 3% of the general populationAbout 1% to 3% of the general population

90% of MR persons are labeled with mild mental 90% of MR persons are labeled with mild mental retardationretardation

Gender DifferencesGender Differences MR occurs more often in males, male-to-female ratio MR occurs more often in males, male-to-female ratio

of about 1.6:1of about 1.6:1

Course of MRCourse of MR Tends to be chronic, but prognosis varies greatly Tends to be chronic, but prognosis varies greatly

from person to personfrom person to person

Mental Retardation (MR): Mental Retardation (MR): Psychosocial ContributionsPsychosocial Contributions

Cultural-Familial RetardationCultural-Familial Retardation Believed to cause about 75% of MR cases and is Believed to cause about 75% of MR cases and is

the least understoodthe least understood

Believed to result from combination of Believed to result from combination of biological (low IQ) and social factorsbiological (low IQ) and social factors

Neglect, abuse, poor nutrition Neglect, abuse, poor nutrition

Associated with mild levels of retardation on IQ Associated with mild levels of retardation on IQ tests and good adaptive skillstests and good adaptive skills

Lower end of distributionLower end of distribution but probably distinct but probably distinct etiology from those w clear organic causesetiology from those w clear organic causes

Mental Retardation (MR): Mental Retardation (MR): Biological ContributionsBiological Contributions

Genetic ResearchGenetic Research

MR involves multiple genes, and at times single MR involves multiple genes, and at times single genesgenes

Chromosomal Abnormalities and Other Forms of MRChromosomal Abnormalities and Other Forms of MR

Down syndrome – Trisomy 21Down syndrome – Trisomy 21

Fragile X syndrome – Abnormality on X Fragile X syndrome – Abnormality on X chromosomechromosome

Maternal Age and Risk of Having a Down’s BabyMaternal Age and Risk of Having a Down’s Baby

Nearly 75% of cases cannot be attributed to any Nearly 75% of cases cannot be attributed to any known biological causeknown biological cause

Specific genetic syndromes Specific genetic syndromes associated with MRassociated with MR

Down SyndromeDown Syndrome Fragile X syndromeFragile X syndrome

Down Syndrome

Down SyndromeDown Syndrome Most common chromosomal form of MRMost common chromosomal form of MR Prevalence: about 1 out of every 700 live Prevalence: about 1 out of every 700 live

birthsbirths As many of 75% of trisomy 21 result in As many of 75% of trisomy 21 result in

miscarriages or stillbirths.miscarriages or stillbirths. The older the mother, the higher the (p) The older the mother, the higher the (p)

of DS (e.g., Maternal age of 20 = 1 in of DS (e.g., Maternal age of 20 = 1 in 2000; 35 = 1 in 500; 45 = 1 in 18)2000; 35 = 1 in 500; 45 = 1 in 18)

Theory - ova (eggs) produced in youth Theory - ova (eggs) produced in youth are exposed to toxins, radiation - are exposed to toxins, radiation - damageddamaged

Down Syndrome (cont.)Down Syndrome (cont.)

Health issuesHealth issues: Congenital heart defects : Congenital heart defects (50), hearing loss (66-89), ophthalmic (50), hearing loss (66-89), ophthalmic conditions (60), endocrine conditions conditions (60), endocrine conditions (e.g., hypothyroidism) (50-90), obesity (e.g., hypothyroidism) (50-90), obesity (50-60), dental problems (60-100), (50-60), dental problems (60-100), seizure disorders (6-13), high risk of seizure disorders (6-13), high risk of Alzheimer's disease.Alzheimer's disease.

Down Syndrome (cont.)Down Syndrome (cont.)

Adaptive behaviorAdaptive behavior: In general : In general children with DS show higher AB children with DS show higher AB levels than intelligencelevels than intelligence

PersonalityPersonality: Sociable and pleasant. : Sociable and pleasant. Dual DXDual DX: Less often and less : Less often and less

severe maladaptive behavior and severe maladaptive behavior and psychopathologypsychopathology

Fragile X Syndrome

Fragile X syndromeFragile X syndrome Most common known inherited form Most common known inherited form

of MRof MR Prevalence = 1 in 4000 males and at Prevalence = 1 in 4000 males and at

least half that in females.least half that in females. The marker was an X chromosome The marker was an X chromosome

with a small, pinched-off piece of with a small, pinched-off piece of genetic materialgenetic material

Mothers often have learning Mothers often have learning disabilitiesdisabilities

Fragile X syndrome (cont.)Fragile X syndrome (cont.) Physical featuresPhysical features: 80% of post pubertal : 80% of post pubertal

boys and men with this disorder have boys and men with this disorder have enlarged testicules (about twice the size). enlarged testicules (about twice the size).

Other physical features:Other physical features: long narrow face long narrow face and prominent ears, flat feet, hyper and prominent ears, flat feet, hyper extensible finger joints, soft skinextensible finger joints, soft skin

Features become more pronounced with Features become more pronounced with age and are subtle in childhoodage and are subtle in childhood

Few significant medical problems are Few significant medical problems are associated with fragile X (seizures in associated with fragile X (seizures in about 20%)about 20%)

Fragile X syndrome (cont.)Fragile X syndrome (cont.)

IQ levels vary from moderate levels of MR IQ levels vary from moderate levels of MR to the average range of functioning (varies to the average range of functioning (varies with genetic status, gender, and age)with genetic status, gender, and age)

In general, females are less impaired than In general, females are less impaired than males males

Many males seem to show declines in their Many males seem to show declines in their IQ scores over time. IQ scores over time.

Treatment of MRTreatment of MR

For mild MR, tx is similar to that for learning For mild MR, tx is similar to that for learning disabilitiesdisabilities

For more severe MR, treatment is similar to For more severe MR, treatment is similar to that for PDDthat for PDD

Goals include communication, social Goals include communication, social development, independent living and job development, independent living and job skillsskills

People with MR often Benefit from Such People with MR often Benefit from Such InterventionsInterventions

developmental disorders.ppt

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