intellectual disability

Question 1

ICD 10 definition of intellectual disability

Answer 1

a condition of arrested or incomplete development of the mind, which is especially characterised by impairment of skills manifested during the developmental period, which contribute to the overall level of intelligence
i.e. cognitive, language, motor and social abilities

Question 2

intellectual disability criteria

Answer 2

1. intellectual impairment (IQ <70) e.g. Wechsler adult intelligence scale
2. social or adaptive dysfunction (vineland adaptive behaviour scale)
   - deficits/impairments in ≥2 of following adaptive skills: communication, self-care, home living, social skills, community use, self-direction, health and safety, functional academics, leisure and work
3. onset in the developmental period (<18y/o)

Question 3

prevalence of learning disabilities

Answer 3

statistically the prevalence of people w/ IQ<70 should be 2.5% but in practice is 1-2%:

• differential mortality (more severe degree of intellectual disability –> higher mortality compared to general pop)
• role of functioning (those w/ IQ <70 but have no problems functioning wouldn’t be defined as having a learning disability)

Question 4

how do we classify the severity of learning disabilities

Answer 4

both intellectual and adaptive functioning is used to classify severity of LD

Question 5

different severities of LD

Answer 5

mild LD - IQ 50-69 or functional age 9-12y/o
moderate LD - IQ 35-49 or functional age 6-9y/o
severe LD - IQ 20-35 or functional age 3-6y/o
profound LD - IQ <20 or functional age 3y/o

severe and profound LD are mainly based on clinical judgement rather than IQ

Question 6

why do we not use the term mental age in describing people with learning disabilities

Answer 6

unhelpful term

treat the patients as adults

Question 7

risk protection in intellectual disabilities

Answer 7

someone w/ a mild learning disability might be able to live independently to some extent but there would be concerns about their ability to recognise risk and safely manage difficult situations

there may be difficulty recognising social risks and dangers re. exploitation

Question 8

verbal communication in moderate learning difficulties

Answer 8

some people w/ moderate LD have relatively good expressive verbal communication although their receptive may be more impaired

this can lead to difficulties w/ people appearing to understand more than they can and becoming distressed as a result of not understanding some of the things happening around them

Question 9

what are the main causes of intellectual disability

Answer 9

inherited

acquired

Question 10

inherited causes of LD

Answer 10

single gene: fragile X, PKU, Retts syndrome

microdeletion/duplication: DiGeorge syndrome, Prader-Willi, Angelman syndrome

chromosomal abnormality: Down’s syndrome

Question 11

acquired causes of LD

Answer 11

infective: e.g. rubella, zika virus
traumatic: hypoxic injury during birth, head injury during childhood
toxic: foetal alcohol syndrome, sodium valproate use during pregnancy etc
idiopathic: for most pts the cause is unknown - ~70% of cases

Question 12

health inequalities in people w/ LD

Answer 12

significant problem and recognised to lead to early death

social exclusion
socioeconomic deprivation 
inaccessible services
discrimination
challenges to communication
lack of appropriate knowledge and skills of professionals
minimal evidence base from research

Question 13

common and/or important physical conditions associated w/ LD

Answer 13

epilepsy

sensory impairments

obesity

GI problems

resp problems

cerebral palsy

orthopaedic problems

dermatological and dental problems

Question 14

epilepsy and LD

Answer 14

increased incidence and complexity w/ severity of LD (10-50%)

Question 15

sensory impairments and LD

Answer 15

hearing 40%
vision 20%
earwax

Question 16

obesity and LD

Answer 16

predisposes to other health problems

Question 17

GI problems and LD

Answer 17

swallowing problems

reflux oesophagitis

Helicobacter pylori

constipation

Question 18

resp problems and LD

Answer 18

chest infections

aspiration pneumonia

Question 19

cerebral palsy and LD

Answer 19

esp w/ severe LD

Question 20

orthopaedic problems and LD

Answer 20

joint contractures

osteoporosis

Question 21

dermatological and dental problems w/ LD

Answer 21

33% unhealthy gums

80%

Question 22

why is there a psychiatric speciality for those w/ LD

Answer 22

higher incidence of psychiatric disorders in those w/ LD

more severe LD - higher prevalence of psychiatric disorder

people w/ mild LD may present in broadly similar way to general pop

presentation of mental illness different, esp in mod-profound LD

difficulties in describing internal world, less complex delusions

baseline presentation is different

those w/ lower IQ/comms difficulties often present w/ challenging behaviour

where there is less verbal communication, observable signs are relied on more in making the diagnosis e.g. weight loss, withdrawal, agitation, tearfulness, behavioural disturbance

special training and MDT working

Question 23

assessment areas in psychiatry of LD

Answer 23

presence and severity of LD
aetiology incl. genetics
associated biomedical conditions 
psycho-social assessment 
psychiatric disorders, their cause and consequences

Question 24

schizophrenia/psychosis in LD

Answer 24

3% point prevalence compared to 1% general pop

associated w/ change in personality and reduction in functional abilities - people w/ LD often struggle to describe some of the more complex symptoms; -ve symptoms have a significant impact

‘self-talk’ common in LD - can be mistaken for psychosis

Question 25

mood disorders in LD

Answer 25

increased incidence

less likely to complain of mood changes and noted by change in behaviour e.g. biological symptoms - early morning waking, appetite and weight change

Question 26

anxiety disorders in LD

Answer 26

common

ritualistic behaviour and obsessional themes significantly increased in LD

obsessions hard to describe by people w/ LD but compulsions more readily observed

Question 27

what % of people w/ autism have a LD

Answer 27

50%

Question 28

over-activity syndromes in LD

Answer 28

ADHD much higher incidence
many severe LD children are overactive. distractible and impulsive but NOT to the extent that would indicate ADHD diagnosis (it is developmentally appropriate given their level of intellectual impairment)

Question 29

challenging behaviour and self-injury in LD

Answer 29

wide range of behaviours - socially constructed rather than diagnostic term e.g. aggression towards others and self-injury, destruction of property, wandering, oppositional behaviour, sexually inappropriate behaviour, pica etc

frequent end point for wide range of conditions

general trend is towards greater prevalence of problem behaviour w/ increasing severity of LD (BUT people w/ profound LD exhibit less outwardly)

usually a result of stress/distress

Question 30

forensic problems and LD

Answer 30

mild LD have similar rates of offending to the general pop but different profile of offending

IQ <70 over-represented for arson and sexual (usually exhibitionism) in prison pop

often inappropriate for people w/ LD to be managed in prison setting - diverted into mental health services

Question 31

what is diagnostic overshadowing

Answer 31

presenting symptoms are put down to the LD rather than seeking another, potentially treatable cause

often when someone is seen w/ challenging behaviour

Question 32

diagnostic overshadowing - causes of changes in behaviour

Answer 32

social - change in carers, lack of support, lack of social activities

psychological - bereavement, abuse

physical - pain/discomfort, e.g. ear infection, toothache, constipation, reflux oesophagitis, deteriorations in vision/hearing

psychiatric - depression, anxiety, psychosis, dementia

Question 33

what can health professionals do to prevent diagnostic overshadowing

Answer 33

take time and be patient

value what is being communicated

recognise non-verbal cues

find out about the person’s alternative communication strategies if verbal is difficult e.g. typical non-verbal cues, symbols, sign language

explain things clearly in an appropriate way (verbal, pictures); simple, jargon free language

be prepared to meet the person several times to build up rapport and trust

use the knowledge and support of carers

Question 34

orthopaedic problems and LD

Answer 34

joint contractures

osteoporosis