intellectual disability Flashcards
ICD 10 definition of intellectual disability
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
intellectual disability criteria
- intellectual impairment (IQ <70) e.g. Wechsler adult intelligence scale
- 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 - onset in the developmental period (<18y/o)
prevalence of learning disabilities
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)
how do we classify the severity of learning disabilities
both intellectual and adaptive functioning is used to classify severity of LD
different severities of LD
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
why do we not use the term mental age in describing people with learning disabilities
unhelpful term
treat the patients as adults
risk protection in intellectual disabilities
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
verbal communication in moderate learning difficulties
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
what are the main causes of intellectual disability
inherited
acquired
inherited causes of LD
single gene: fragile X, PKU, Retts syndrome
microdeletion/duplication: DiGeorge syndrome, Prader-Willi, Angelman syndrome
chromosomal abnormality: Down’s syndrome
acquired causes of LD
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
health inequalities in people w/ LD
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
common and/or important physical conditions associated w/ LD
epilepsy
sensory impairments
obesity
GI problems
resp problems
cerebral palsy
orthopaedic problems
dermatological and dental problems
epilepsy and LD
increased incidence and complexity w/ severity of LD (10-50%)
sensory impairments and LD
hearing 40%
vision 20%
earwax
obesity and LD
predisposes to other health problems
GI problems and LD
swallowing problems
reflux oesophagitis
Helicobacter pylori
constipation
resp problems and LD
chest infections
aspiration pneumonia
cerebral palsy and LD
esp w/ severe LD
orthopaedic problems and LD
joint contractures
osteoporosis
orthopaedic problems and LD
joint contractures
osteoporosis
dermatological and dental problems w/ LD
33% unhealthy gums
80%
why is there a psychiatric speciality for those w/ LD
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
assessment areas in psychiatry of LD
presence and severity of LD aetiology incl. genetics associated biomedical conditions psycho-social assessment psychiatric disorders, their cause and consequences
schizophrenia/psychosis in LD
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
mood disorders in LD
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
anxiety disorders in LD
common
ritualistic behaviour and obsessional themes significantly increased in LD
obsessions hard to describe by people w/ LD but compulsions more readily observed
what % of people w/ autism have a LD
50%
over-activity syndromes in LD
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)
challenging behaviour and self-injury in LD
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
forensic problems and LD
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
what is diagnostic overshadowing
presenting symptoms are put down to the LD rather than seeking another, potentially treatable cause
often when someone is seen w/ challenging behaviour
diagnostic overshadowing - causes of changes in behaviour
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
what can health professionals do to prevent diagnostic overshadowing
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
