Biological Risk Factors

Biological risk factors include the following: • Some genetic disorders are linked with intellectual disability and psychiatric illness. For example, Down syndrome is associated with dementia and fragile X with Attention Deficit Hyperactivity Disorder.  • There is increasing evidence that genes contribute to behaviour.  Certain genetic syndromes are associated with specific behavioural problems, for example Lesch-Nyhan syndrome is associated with severe self harming behaviour and Prader Willi syndrome with over-eating. • Sensory disabilities are common in people with intellectual disability. Disorders of hearing and vision are associated with increased risk of psychotic illness in the general population. • Epilepsy is common in people with intellectual disability and is associated with depression and psychotic illness. • Distressing side-effects of medication (such as restlessness with antipsychotic medication) can go unrecognised or be mis-attributed to the intellectual disability. Sedation can lead to impairments in attention, concentration, memory and learning. Antiepileptic medication affects behavioural and cognitive side-effects. • People with intellectual disability may not be able to access the community, for a number of reasons, to attend health services leading to exclusion from health screening, promotion and prevention, in addition to routine monitoring of physical illness. • People with intellectual disability may not recognise symptoms of ill health and these can also go unrecognised by families and carers.