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.