F81.9
DESCRIPTION
Co-occurring psychiatric, neurodevelopmental, medical and physical conditions are frequent, some with rates 3-4 times higher than the general population. The most common co-occurring psychiatric and neurodevelopmental disorders are ADHD, bipolar and depressive disorders, anxiety disorders, ASD, stereotypic movement disorder with/without self-injurious behaviour and impulse-control disorders. Severe intellectual disability may present with aggression including harm to others and property destruction. Inappropriate sexual behaviour may also occur. Epilepsy is associated with increased rates of ADHD, behavioural dysregulation and psychosis.
DIAGNOSTIC CRITERIA
Diagnostic criteria for psychiatric disorders in children with intellectual disability are the same as those for the general paediatric population. However, symptom expression may vary with developmental stage or level of intellectual functioning.
GENERAL AND SUPPORTIVE MEASURES
- Exclude medical conditions in children presenting with behavioural disturbances, particularly in children who are not able to communicate symptoms verbally (e.g. seizures, dental caries, covert infections, poisoning, foreign bodies, space occupying brain lesions and drug side effects).
- Exclude emotional, physical or sexual abuse in a child presenting with persistent adverse behaviour and emotional distress (especially in non-verbal children).
- Parental guidance is an important part of the management of children presenting with behavioural problems (psycho-education, behaviour management).
- Behaviour modification principles form the basis of psychosocial intervention.
MEDICATION TREATMENT
- Psychotropic medication treatment should only occur as part of a multidisciplinary diagnostic and therapeutic intervention.
- Treat according to the primary psychiatric condition, as per treatment guidelines.
For disruptive behaviour disorders in intellectual disability:
- Risperidone is registered for children with developmental disorders > 5 years old:
- Dose 5 – 12 years: 0.01 mg/kg/day.
- Maintenance 0.02 - 0.04 mg/kg/day.
- Do baseline blood tests and ECGs, particularly in children with underlying medical conditions.
- Start with the lowest doses possible.
- Increase dosages cautiously as children with intellectual disability may be more susceptible to adverse effects such as extrapyramidal side effects (EPSEs), neuroleptic malignant syndrome (NMS) or the disinhibiting effects of benzodiazepines.
REFERRAL
- Children who fail to respond to initial treatments should be referred to a paediatrician for further assessment and management.
- Children presenting with severe aggression, inappropriate sexual behaviour or significant self-injurious behaviour should be referred for a diagnostic assessment or admission to an intellectual disability service (if such a service exists in the region) or to a tertiary level child psychiatry service.
- Children presenting with psychosis or a manic episode should undergo medical work-up and be referred to a paediatrician or child psychiatrist as appropriate.
- Refer to a social worker or child protection services if abuse is suspected.