Mental Retardation

Madan Mohan.K.S. & Karan.A.K.

Mental RetardationAn understanding of “normal”

IQ Tests – Of Cognitive Function Wechsler Intelligence scale for children III(6-17y) Wechsler Adult Intelligence scale(16-74y) Stanford-Binet Intelligence Scale(2y-adult) Kaufman Adolescent and Adult Intelligence Test(11-

85y) Tests Of Nonverbal Intelligence – 2(5y-85y)

Robert Edgerton & his c/o Fred Barnett Adaptive skills are critical to the long term

adjustment and success of people with mental retardation.

Measures of Adaptive Behavior Vineland Adaptive Behavioral Scales(0-18yrs) Scales Of Independent Behavior(0-80+) AAMR Behavioral Scales(3-18y) Kaufman Functional academic skills(15-58+) Street Survival skills questionnaire(9-40+)

Does Low IQ say it all?

Definitions / Classifications Esquirol(1843) Wilbur(1852) Alfred Tredgold(1922) AAMR 1983

IQ levels Mild 55 – 70Moderate 40 – 55Severe 25 - 40 Profound <25

AAMR 1992 – IQ levels < 70 - 75

10 Adaptive skills: communication, self-care, home living, social skills, leisure, health and safety, self-direction, functional academics, community use, and work.

Eg - Intermittent needs for health and safety - Limited needs for supports in self

care

Classification Contd….. AAMR 2002

IQ levels <2 SD below the mean ~70 Adaptive Behavior

Performance of <2SD below mean of either One of the 3 types of adaptive behavior – conceptual,

social or practical skills An overall score on a std measure of conceptual, social or

practical skills

DSM-IV-TR Criteria Significantly sub average intellectual functioning : IQ

of ~70 or below on an individually administered IQ test.

Concurrent deficits or impairments in present adaptive functioning in at least two of the skill areas.

Onset before the age of 18 years.

ICD – 10 Codes For MR(Axis III)

F70 Mild Mental Retardation IQ 50-69 F71 Moderate MR 35-49 F72 Severe MR 20-34 F73 Profound MR <20 F78 Other MR

Sensory,Physical,Behavioral

F79 Unspecified MR F7x.0 No/Min impairment of behavior F7x.1 Significant impairment of behavior F7x.8 Other impairments of behavior F7.x9 Without mention of impairment of

behavior

Fragile X Syndrome Single gene mutation located on the X chromosome. Since both males (XY) and females (XX) each have at

least one X chromosome, both can be carriers or have the syndrome.

If a father is a carrier, he can only pass the gene defect to his daughters, since he transmits a Y chromosome to his sons.

If a mother is the carrier, she can pass the gene defect to either sons or daughters, since she contributes an X chromosome to each. Children of carrier mothers have a 50% chance of inheriting the

gene, since the mother has two Xs to give and only one is affected.

Down SyndromeJohn Langdon Down- clinically identified

the condition in 1866. Caused by extra genes in the 21st

chromosome.

MILD(~85%) Cognitive standpoint:

6th grade level or higher; can perform vocational-job related skills

Affective Acceptable social skills: able to communicate,

acquire jobs, marry Psychomotor

Delayed motor skills Often obesity issues because of sedentary

lifestyle

MODERATE(~10%) Cognitive

2nd grade educational abilities

Affective Not as independent as mild; needs assistance 20% - independent; 60% - partially dependent;

20% - totally dependent

Psychomotor Obesity; greater motor delays Supportive services required throughout life

SEVERE(3-4%) & PROFOUND(1-2%) Cognitive

Learn some (not a lot) fundamental motor skills, lack ability to attend to obvious stimuli, very dependent upon others/lack self-help skills, most cases non-verbal

Affective Lack play skills-don’t get the notion

Psychomotor Retention of primitive reflexes Concurrent motor, ambulatory and neurological problems Extensive training required even to complete most

rudimentary aspects of self care (eating, toileting etc) Require total supervision and care throughout life

Developmental Considerations Child Related Aspects

Overview – Children with MR traverse the same sequences of development as do non retarded children but certain forms of MR show intellectual strengths and weaknesses not generally found in non retarded children

Sequences – For almost all children with MR, the sequence of developmental progress is almost the same as for non retarded children. (Piagetian cognitive development – sensorimotor, pre operational, concrete operational, formal operational). However, the sequence of development varies in children with autism, epilepsy etc.

Rates of development – children with MR develop at slower rates than those of non retarded children. Children with different types of MR, however may have periods of speeded or slowed development

• Contextual Aspects•Mother Child Interactions•Family Reactions

Increased Vulnerability to Mental Disorders in persons with MR

Neuropathological process responsible for MR may

also cause increased risk of mental illness Increased likelyhood of loss and separation Communication deficits Vulnerability to abuse and exploitation Heightened family stress Risk of limited network of social relationships and

repertoire of social skills Risk of reduced opportunities for development and

exercise of recreational/occupational skills Adverse effect on self esteem of

disability/dysmorphology

Psychopathology in MR ADHD – Diagnosis is based on developmental considerations – motor

hyperactivity, impulsivity, inattention. Hence threshold for diagnosis in severe-profound MR should be elevated.

Impulse control disorder: Self Injury and Aggression – common in MR, increase with greater severity of cognitive disability. Typically takes the form of chronic repetitive and frequently stereotyped behavior resulting in trauma (self biting – Lesch Nyhan, finger and nail pulling – Smith Magenis syndrome). As the above sym are non specific, one must account the presence/absence of variety of factors to arrive at the presumptive dx(whether it serves a communicative fn/invariant of its topography – hitting only right ear suggesting ear infection; whether it occurs from a regression from previous level of function; whether its situational; associated neuro vegetative signs)

Oppositional Defiant Disorder Anxiety Disorders – Separation anxiety, overanxious disorder, OCD,

panic disorder, generalized anxiety disorder, PTSD. Engaged in behavior that appears compulsive/driven – OCD NOS. Simple repetitive behavior does not amount to OCD. Common symptoms of anxiety in MR – aggression, agitation, compulsive or repetitive behavior, self injury, insomnia. Panic may be expressed as agitation, screaming, crying, clinging.

Psychopathology Contd….

Eating Disorders – Anorexia nervosa, Bulimia, Pica

Organic Mental Disorders – Anyone woth MR has some ‘organic cerebral dysfunction’ thus any psychiatric condition could be regarded as organic.

Psychosis – Diagnosis of classical schizophrenia in children with profound MR with limited communicative ability is almost impossible. Dx based on presumptive response to hallicinations.

Mood Disorders – A change in mood from baseline – recent onset liability, tearfullness, mood elevation, irritability, social withdrawal, problems in sleep or appetite.

Other Disorders – Tourette, Somatoform disorders, depersonalisation disorders, sexual disorders are less frequent.

Thank You