Prevalance

Question 1

LD

Answer 1

1-3% of the population

Incidence difficult to calculate given mild disabilities may be unrecognisable until middle childhood

Highest incident is in school aged children, peak 10-14

M:F = 1.5:1

Question 2

Schizophrenia in people with LD

Answer 2

3%

Earlier age of onset (mean 23)

More commonly associated with epilepsy, negative symptoms, impairment of episodic memory

In severe LD there may be unexplained aggression, bizarre behaviour, labile mood, increased mannerisms + stereotypies

Thought disorder + complex delusional beliefs less evident

Question 3

Epilepsy

Answer 3

Severe LD = 30-50%
Mild LD = 15-20%

Angelman = 90%
Rett = 90%
Tuberous sclerosis = 90%
Fragile X = 25%
Down = 5-10%

Question 4

LD severity

Answer 4

Mild = 85%
Mod = 10%
Severe = 3-4%
Profound = 1-2%

Question 5

Aetiology of LD

Answer 5

No definite etiology = 30-40%

Environmental influences = 15-20%

Pregnancy related and perinatal problems = 10%

Genetic inheritance = 5%

Acquired general medical conditions = 5%

Question 6

Comorbidities

Answer 6

Schizophrenia = 3%

BPAD = 2-12%

Epilepsy = 30-50% severe, 15-20% mild

ADHD = 20%

Self-injurous behaviour = 10%

Question 7

Offending behaviour

Answer 7

Offending = 2-10%
Within prison populations = 2-30%
0.5-1.5% of prisoners are diagnosed with ID
More common in mild to mod
Violent, sexual offending, arson

Question 8

Victimisation

Answer 8

More vulnerable to exploitation, bullying & abuse

Doubles the risk of victimisation

Question 9

Depression

Answer 9

4%

Question 10

Secure hospital ID services

Answer 10

50% PD
30% ASD
30-50% major psychiatric disorder
30-50% substance misuse / dependence
20% epilepsy