Epidemiology and Diagnosis of Intellectual Disabilities

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Questions and Answers

What is a significant challenge in defining intellectual disabilities?

Definitions are universally agreed upon across all research

It is a socially constructed category that can change over time and culture (correct)

Lack of evidence for intellectual impairment

There is a singular definition that applies to all populations

Why is research on intellectual disabilities often complicated?

Different researchers employ various definitions and face limited epidemiological data (correct)

The term is widely recognized and accepted worldwide

All researchers agree on the definitions and data is abundant

There is too much standardization in the definitions used

According to ICD-10, which of the following is necessary for diagnosing significant intellectual impairment?

Self-reported ability to perform daily tasks

Observational assessments focusing solely on behavior

One documented instance of learning difficulty

Evidence of significant intellectual impairment, often evaluated through IQ (correct)

What term does the newer classification use to refer to individuals with learning disabilities?

Persons with Learning Disabilities (PwLD) Signup and view all the answers

What factor contributes to the variability in definitions of intellectual disabilities across societies?

Cultural perceptions and values regarding disability Signup and view all the answers

What is a common issue with the categorization of intellectual disabilities?

It is influenced by societal changes over time. Signup and view all the answers

Which term is used in newer classifications for individuals previously referred to as having learning disabilities?

Intellectual disabilities Signup and view all the answers

Why is it challenging for researchers to reach a consensus on definitions of intellectual disabilities?

Different researchers use varying definitions based on societal perspectives. Signup and view all the answers

In the ICD-10 classification, what is required for evidence of significant intellectual impairment?

An IQ measurement Signup and view all the answers

What complicates research related to intellectual disabilities?

Limited epidemiological data and differing definitions. Signup and view all the answers

What aspect of intellectual disabilities is highlighted as socially constructed?

The definitions of intellectual disabilities Signup and view all the answers

What does the term 'Person with Learning Disabilities' refer to in newer classifications?

Individuals previously categorized as having mental retardation Signup and view all the answers

Which factor significantly complicates epidemiological research on intellectual disabilities?

The absence of a universally accepted definition Signup and view all the answers

Which characteristic is deemed necessary according to the ICD-10 for diagnosing intellectual impairment?

Evidence of significant intellectual impairment through IQ testing Signup and view all the answers

What does variability in the definition of intellectual disabilities indicate?

The influence of cultural and temporal considerations Signup and view all the answers

Study Notes

Pre-lecture Pt1: Epidemiology, Diagnosis, Key Features

Significant proportion of the population have an intellectual disability (ID).
Definitions are socially constructed, changeable, and dependent on the society. No single definition exists.
Significant variability in research due to differing definitions (e.g., older Learning Disabilities vs. newer Intellectual Disabilities).
ICD-10 diagnostic criteria:
- Evidence of significant intellectual impairment (IQ <70, 2x SD below average).
- Impairment in functional abilities, based on age.
- Presence of impairment (<18 years) during developmental period.
- Impairment of adaptive/social functioning, requiring significant assistance in survival (eating, clean, clothes), or social/community adaptation.
Mild/Moderate/Severe IDs are categorized, largely based on IQ scores. Severe/profound IDs have IQ scores below 35.

Pre-lecture Pt2: History

Middle ages to 19th century: Idiocy and lunacy.
Victorian era: ID considered a social problem, lacking reasonable ability.
20th century: Rise of institutionalization.
Post-war: NHS and welfare state support.
1940s: Special schools; patients becoming hospital inmates.
1971: "Better services" White Paper—shift towards community-based care.
Social theories driving change: Normalization, and Social Role Valorisation.

Epidemiology

Approximately 2-2.5% of the population has an IQ of <70, but only 0.5-1% known to LD services; 0.3-0.4% = severe/profound.
Prevalence is higher in lower socio-economic groups.
Existence of established single cause (genetic/environmental) for ID across all socioeconomic groups.

Mental Health in People with ID

Inadequate service provision with people with Intellectual Disability often being left in institutions.
Under-diagnosis
Diagnostic overshadowing: Assuming symptoms are solely due to ID, rather than considering other potential mental health issues.
Prevalence of mental health conditions in people with ID is variable—10-80% depending on the specific definitions involved.
25-40% in the general LD population (psychiatric evaluation).

Autism Spectrum Disorder (ASD)

Epidemiology: Affects 1% of children and 1% of adult UK households, with men being twice as likely to have ASD than women.
Social isolation, lowest education qualifications, and rarely full-time employment are common to those diagnosed with ASD.
16% of adults with ASD will experience new mental health problems in their 20s.
High IQ often associated with higher risk of mental health problems in both ASD and general populations.
Commonly reported difficulties incl.: high anxiety levels, delusions and social anxiety, depression.

Interventions in ASD

Develop social skills
Improve self-help, self-care, independence, and conversational abilities.

Mental Capacity Act

Defines criteria for someone to be deemed capable of making a decision.
Prevents decisions from being made by others on people who are deemed lacking capacity, particularly when relating to a specific decision
Individuals deemed to have capacity if they can understand, retain, weigh up information, and communicate it

Definition and Terminology

Intellectual disability is characterized by significant limitations in intellectual functioning and adaptive behavior from the early stages of life
Current criteria emphasize low IQ score (generally below 70) and impairments in adaptive functioning.
Classification and severity are categorized into degrees by IQ and adaptive functioning (mild, moderate, severe, and profound).
The prevalence rates of intellectual disabilities vary largely between studies.
Factors that can impact prevalence reported include:
- Method of ascertainment (population vs. pre-identified)
- Inclusion criteria (IQ alone or in combination with adaptive functioning).
- Age of the study participants
- Income levels of the affected countries

Causes of Intellectual Disability

Two-group theory identifies causes as either pathological (rare medical-genetic events) or extreme environmental factors.

Socio-cultural/Familial causes of intellectual disability

Common adverse family and social risk factors
Low parental IQ
Lack of environmental stimulation
Social deprivation
Often associated with mild intellectual disability.

Chromosomal Anomalies in intellectual disability

Variations from typical diploid chromosome set.
Can be identified via genetic testing.

History & Prevalence of Intellectual Disability

Historical perspective of understanding and treating intellectual disability.

Interventions in Intellectual Disability

Service principles that should be given to those with intellectual disabilities- O'Brien (1987, 1992)
- Community presence, choice, respect, competence
Service principles that are important to those with intellectual disabilities—Valuing People & Valuing People Now policies (2001, 2007).

Research Directions and Terminology

Directions for research, including focus, mechanisms, investigation etc.
Changing terminology, including old vs new terminology (e.g., mental retardation vs. intellectual disability).

Diagnosing Intellectual Disability

Intellectual functioning (e.g., IQ testing).
Adaptive functioning (e.g., Vineland Adaptive Behaviour Scales).
Developmental history (e.g., informant reports).
Diagnostic criteria (2x standard deviations below mean in IQ, and adaptive functioning limitations).

Physical Health in Intellectual Disability

Increased risk of certain physical conditions.
Sensory impairments.
Epilepsy
Physical disabilities.
Mobility impairment.

Mental Health in Intellectual Disability

Increased risk of mental health conditions
Difficulty expressing symptoms and reporting emotions.
Conditions like Autism, ADHD, depression, psychosis.

'Challenging Behaviour'

Culturally recognized as abnormal and intense behaviour leading to a person's safety or others'. This is not a diagnosed mental health issue

Additional Topics

Healthcare for people with ID.
Mental health (including diagnostic overshadowing, stigma, discrimination, lack of education/skills leading to delayed treatment).
Psychosocial interventions
Adapting communication
Case vignette (assessment of problems and potential solutions).

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Description

Explore the epidemiology, diagnosis, and key features of intellectual disabilities (ID). This quiz delves into the definitions, historical context, and diagnostic criteria as outlined by ICD-10, providing a comprehensive overview of the subject. Gain insights into the categorization of ID based on severity and functionality.