2. Contents
• General Description
• Etiology
• Diagnostic criteria
• Classification
• Clinical presentation/ clinical features
• Cultural considerations
• Comorbidity and Differential/s
• Course and prognosis
• The Formulation (biopsychosocial model)
• Management
3. INTRODUCTION
DSM-5 defines intellectual disabilities as neurodevelopmental disorders that begin
in childhood and are characterized by intellectual difficulties as well as difficulties in
- Conceptual
- Social
- practical areas of living.
4. General Description of Intellectual Disability (ID)
• Intellectual Disability (ID) is characterized by significant limitations in both intellectual
functioning (reasoning, learning, and problem solving) and in adaptive behaviour (conceptual,
social, and practical skills) that emerges before the age of 18 years.
• In DSM-5, ID is classified as mild, moderate, severe, or profound based on overall intellectual
functioning
• Severity levels are classified according to intelligence quotient (IQ)
Mild (50–69)
Moderate (35–49)
Severe (20–34)
Profound (below 20).
• A variation of ID called global developmental delay is for children younger than 5 years with
severe defects exceeding those above.
• In DSM-IV, it meant an IQ of about 70, but in DSM-5, it is categorized as a condition that may be
the focus of clinical attention, but no criteria are given.
10. Clinical presentation
Mild intellectual disability Moderate intellectual disability Severe intellectual
disability
Profound intellectual disability
Not diagnosed in child until
social and communication skills
are challenged by the school in
1st or 2nd grade
Observable at a younger age
due to slow communication
skills and social isolation
Evident in pre-school
years due to minimal
speech and impaired
motor development
Constant supervision due to severely
limited communication and motor skills
Reduced ability to abstract and
egocentric thinking
Academic achievement is
limited to middle elementary
level
Language might develop
in school age years
By adulthood some speech
development may be present
Communication deficits, poor
self –esteem, lack of
spontaneity
Appear frustrated by their
limitations
During adolescence they are set
apart by difficulty in
socialisation
Simple self help may be acquired.
Hyperactivity, low frustration tolerance,
repetitive and stereotypic motor
behaviours, self injurious, aggression
and affect instability
11. Comorbidity
• Autism spectrum disorder and exhibited symptoms such as
self-stimulation and self- mutilation and severe IDD.
• Mood disorders, attention-deficit/hyperactivity disorder
(ADHD), and conduct disorder
• Neurological Disorders: Seizure disorders occur more
frequently in individuals with intellectual disability and
prevalence rates for seizures increase proportionally to
severity level of intellectual disability.
• Psychosocial Features: A negative self-image and poor self-
esteem are common features of mildly and moderately
intellectually disabled persons who are aware of their social
and academic
• 2 - 3% of those with IDD have schizophrenia
• Children with profound IDD are less likely to comorbid with
psychiatric disorders
• Mild IDD comorbid more with disruptive and conduct
disorders
12. Cultural
Consideration
• Clinicians should consider cultural norms, socialization practices, and
values when deciding whether a behaviour is maladaptive or not so
they can effectively intervene with understanding of the client.
• Disjoint model of agency focus on the self and the notion that the self
should be independent, happy, and seek to control and influence the
environment – European American cultures.
• Conjoint model is reflective of East Asian/African cultures –
emphasize interdependence, belonging to social groups, and
perception of the environment through the perspective of others.
• Children from different cultures will display different developmental
courses and outcomes, and must be measured according to the
norms of their cultures.
• Gender, race, ethnicity, language, education and class (sociocultural
context) play a role in psychopathology.
• In a cross-cultural comparison study, it was found that Americans
express emotions freely than Chinese.
13. Differentials
• Expressive and receptive speech disorders give impression of ID in child of average intelligence.
• Cerebral palsy may be mistaken for ID
• Chronic debilitating medical diseases may depress and delay functioning and achievement
• Developmental delays due to Severe malnutrition
• Sensory disabilities: Blindness and deafness
14. Course and prognosis
• Underlying impairment does not improve in most cases
• Level of adaptation increases with age
• Persons with mild and moderate have flexibility in adaption to various environment.
• Comorbid psychiatric negatively impact overall prognosis
15. Management
• Intellectual disability is a lifelong condition and therefore has no cure
• However people can learn to improve their functioning over time by:
Mild cases can be enrolled into special schools
learning self care skills and communicating needs.
Training on simple and repetitive jobs
Profoundly affected need hospitalization or constant care
Insight therapy to family and individuals
• Most treatment plans for intellectual disability focus on the person’s:
Strengths
Needs
Support needed to function
• Diagnosis determines which services and protection of rights, such as
special education or home or community services, they are eligible to
receive.
16. Case study
• Dylan was a prematurely born baby as he was birthed at 6 months, he was the first born to his 42
years old mother, a social worker and 48- year old father, business man. The family lived in a high
market estate in Pretoria east.
• The pregnancy was remarkable due to pre-eclampsia and as a result doctors advised early
delivery, Dylan had low weight, irregular temperature and unstable vital signs and had to be in
an incubator, shortly after Dylan and his mother were discharged after 3 months when Dylan’s
weight picked up, his mother went into depression as the father was not supportive during their
stay in hospital because he was pre-occupied with his businesses.
• Although his weight picked up, his milestones were delayed, with Dylan sitting unassisted at 10
months and walking at 18 months. He had delayed in language, his first words appeared at 20
months, his parents were worried about his activity level and his developmental delays however
paediatrician reassured them that despite being born prematurely his development will pick up.
17. Case study Cont.
• At 3 years of age , his preschool teacher noted that he was unable to pay attention and
hyperactive compared to his class mates and prompted parents to get a developmental
evaluation. Results showed modest developmental delays in cognitive, linguistic and motor
functioning.
• Dylan was inattentive, shy and anxious and had poor eye contact. They enrolled him to special
kinder garten. Dylan remained in mainstream classes until he was 7 years. The school
psychologist evaluated him and he met a criteria for learning disability and had an overall IQ of
66
• Dylan struggled with writing tasks and arithmetic, when he reached older primary grades he
began to have more difficulty socially and was then moved to a special school. Dylan was bullied
by some of his peers for being in special school. As he approached adolescence he became
increasingly anxious so much that he occasionally rocked himself and rub his hands and fretted
about day to day issues as well as what would happen next.
• When Dylan was 17 years he was accurately diagnosed with mild intellectual disability.
18. Formulation biopsychosocial model
Biological Psychological Social
Predisposing • High maternal age
• Pre-eclampsia
Precipitating • pre-mature birth
Perpetuating • Maternal Depression
• Lack of early cognitive
stimulation
• Wrong diagnosis
• Poor self image
• Co-morbid of autism
• Being on mainstream
school
• Being bullied
Protective No physical illness
• Good financial
background
• Supportive parents
19. Formulation
• Intellectual disability results when there is an interruption in normal brain function during childhood.
• Advanced maternal age predisposes the mother to late pregnancy complications especially
hypertension related conditions and it is also related to preterm birth, fetal growth restriction and
still birth.
• It can be hypothesized that Dylan's mothers age predisposed her to pre-eclampsia and further led to
Dylan’s preterm birth as a result affecting his normal brain functioning.
• This is evident in Dylan’s low birth weight, irregular temperature and unstable vital signs .
• The depression Dylan's mother experienced post Dylan being discharged could have contributed to
the lack attunement and stimulation that could have mitigated the effects of delayed development .
• Wrong diagnosis, autism comorbid and being on mainstream schooling perpetuated the Dylan's
difficulties in social adapting as well as self esteem.
20. References
Craighead, W.E., Miklowitz, D.J., & Craighead, L.W. ( 2017). Psychopathology: History Diagnosis and
Empirical Foundations. John Wiley and sons
Maddux, J.E. & Winstead, B.A. (2016). Psychopathology: Foundations for a contemporary understanding.
(4th ed.). Routledge
Sadock, B.J., Sadock, V.A, & Ruiz, P. (2014). Kaplan and Sadock’s synopsis of psychiatry: Behavioural
sciences/clinical psychiatry. Lippincott Williams and Wilkins
