Class Notes (837,548)
Canada (510,312)
York University (35,409)
Psychology (4,109)
PSYC 3230 (38)
Lecture

14. Developmental Disorders.pdf

4 Pages
93 Views
Unlock Document

Department
Psychology
Course
PSYC 3230
Professor
James Alcock
Semester
Winter

Description
14. Developmental Disorders Monday, April 1, 2018:54 AM Mental Retardation • Involves a broad delay in cognitive and social functioning • Course is variable ○ Many children improve considerably over time ○ Especially in enriched environments-- encouragement, support, and stimulation • Impoverished environments may lead to deterioration • Training programs to develop community and social skills have been developed • Famous People Players (Toronto)-- mentally and physically challenged actors, highly acclaimed theatre troupe; first theatre company in the world dedicated to people with special needs • Three criteria for diagnosis, according to the DSM-IV: ○ IQ score of 70 or below on a standard IQ test such as WISC or Stanford-Binet ○ Evidence of impaired functioning in two or more areas of adaptive behavior-- e.g., self-care, school, work, social skills ○ Onset before age 18 • Assessed in terms of level of severity: ○ Mild mental retardation: IQ 50-70 (85% of mentally retarded) ○ Moderate mental retardation: IQ 35-49 (10%) ○ Severe mental retardation: IQ 20-34 (3-4%) ○ Profound mental retardation: IQ < 20 (1-2%) • Biological roots ○ Chromosomal and genetic diseases ○ Infectious diseases ○ Brain damage due to environmental toxins ○ Anoxia during birth, etc. • Impoverished home environment can combine with biological factors to produce a more serious disorder Down Syndrome • One of the most common causes of mental retardation • Down symptoms, along with retardation, include: ○ Flat face, small nose, eyes that appear to slant forward because of small folds of skin at inside corners ("mongoloids") small ears, small short hands with curved fifth finger ○ Likely to be obese in childhood and adolescence ○ Tend to have congenital heart abnormalities ○ Tend to show a form of senility • Due to chromosomal abnormalities ○ Each parent contributes one of each of 23 pairs of chromosomes in the zygote ○ Down syndrome occurs when there are three instead of two chromosomes at position 21 ○ Can occur in two ways; [95% is related to the mother's egg] 1) Nondisjunction: one pair of chromosomes in formation of egg or sperm did not separate-- accounts for 80 to 90% of cases (also referred to as "trisomy") □ Risk of nondisjunction rises dramatically in women over 40 (<1 per thousand for women in 20s; 18 per 1000 for women over 40) 2) Translocation: Sometimes material from a chromosome at 21 breaks off in the formation of an egg and fuses with another, so that during cell division, it is carried to the zygote • Karyotype: photograph of all the chromosomes in a cell Phenylketonuria (PKU) • Inherited metabolic disorder caused by a recessive gene carried by one person in 60 Occurs in 1 out of every 12,000 births in North America ○ Occurs in 1 out of every 12,000 births in North America ○ Prevents child from metabolizing the amino acid phenylalanine, found in many foods  Leads to brain damage and retardation • Left untreated during infancy, leads to severe, irreversible mental retardation • May also experience neurobehavioral symptoms-- seizures, tumors, etc. Fragile X Syndrome • A common cause of inherited mental retardation ○ Related to genes on X chromosome (from mother) ○ "Fragile" spot on chromosome shows up when the chromosome is cultured in a laboratory • Fragile X syndrome is a spectrum of mental impairment-- from learning disabilities to severe retardation • Expression is variable • Moderate to severe mental retardation is most common symptom • Macroorchidism (large testicles) • Karyotypes of individuals with Fragile X syndrome are missing a small piece of X chromosome near the end Fetal Alcohol Syndrome • Due to alcohol intake during pregnancy ○ Causes mental retardation and various physical disorders-- e.g., flattened nose, widely separated eyes, reduced head size, below average height and weight Tay-SachsDisease • Caused by recessive gene found mostly in Jewish people of eastern European origin (1 in 25 Jews in North America is a carrier) • Usually causes death before age 5 Others Causes of Retardation • Despite these biological roots, about 75% of people diagnosed as having a developmental handicap have no known organic cause or brain dysfunction! • Most of these are in the mild range ○ Not clear what the cause is-- "inherited low intelligence" combined with an impoverished environment? Autism • If one looks at textbooks from thirty years ago, autism was considered to be "…a subgroup of psychotic disorders" • In DSM-IV, autism is considered to be a pervasive developmental disorder • Symptoms are usually present within the first year and a half of a child's life. In some children, the symptoms may show up early on, within the baby's first few months of life • Other babies may appear normal for a while and then suddenly exhibit an alarming regression at 18 to 24 months • In the beginning the child may:
More Less

Related notes for PSYC 3230

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit