A new study has found antipsychotics used to manage autism and intellectual disability behaviour can have serious side effects.

Antipsychotic medication is typically licensed in the UK for people with serious mental health conditions, such as schizophrenia. But in recent years, some antipsychotic drugs have been prescribed more and more off label. That is, for a condition for which they do not have approval from the medicines regulatory agency to treat.

Off label prescribing can be done under certain circumstances, such as when the prescriber believes it is in a patient’s best interests. For example, antipsychotics are also used to manage behaviour in people with intellectual disabilities and autism. As these drugs have a sedative effect, they can reduce aggression in children with disruptive behaviour.

However, new data analysis by researchers at Swansea University, reported in the Conversation, suggests that treating autistic or intellectually disabled children with antipsychotics can have serious side effects.

The researchers examined how antipsychotics are used in the NHS by linking anonymised hospital, GP and educational records for 3,028 young people who have been prescribed the medication. These came from a bank of medical and school records of 1,488,936 children aged between nought and eighteen, who lived in Wales between 1999 and 2015.

Of the 3,028 children, 16% of those without autism or a learning disability had been diagnosed with a psychotic disorder. And, for children who had autism or a learning disability, only 7% of those given antipsychotics had a psychotic disorder.

Looking further at these records, the researchers found the children with an intellectual disability or autism were more likely to be given an antipsychotic drug. In fact, 2.8% of the children with an intellectual disability had been prescribed antipsychotics, and 75% of these had autism. By contrast, 0.15% of those without an intellectual disability had been prescribed the medication.

The study also found that those with an intellectual disability or autism were being prescribed antipsychotics at younger ages, and for a longer period, than those without an intellectual disability or autism. For example, 50% of those with an intellectual disability or autism had more than twelve prescriptions, compared to 25% of those without. 55% of those with an intellectual disability or autism started taking antipsychotics before the age of fourteen too, compared to 29% of those without.

In addition, the data revealed that children in special schools, those with autism, and those with aggression, were especially likely to be prescribed an antipsychotic. This may be a marker that they have more severe behavioural problems and more challenging behaviour.

Antipsychotics are known to reduce the threshold at which a person has an epileptic seizure. The medication can also lead to weight gain and potentially diabetes. The drugs reduce swallowing, too, so those taking them may be more open to respiratory infections.

In the records the researchers had access to, they found evidence of higher rates of epilepsy, diabetes and respiratory infection requiring hospital admission, in all the young people on antipsychotics. This was compared to rates before being prescribed antipsychotics and compared to those not on antipsychotics.

Looking at mental health, the young people in the study who did not have an intellectual disability or autism had lower rates of depression and injury after taking an antipsychotic. But for those with autism or an intellectual disability, the researchers found higher rates of hospitalisation for depression and injury.

The rate of hospitalisation for depression for those who were never given an antipsychotic, and for those with an intellectual disability before being given antipsychotics was one in two hundred. After antipsychotics, it doubled to one in one hundred. This may be because those with an intellectual disability are less likely to have a manic or agitated type of mental health condition. So taking antipsychotics can bring them down, and lead to depression.

The findings support concerns that have already been expressed about “tranquillising” children with challenging behaviours. Importantly, health providers should work to reduce the use of long term medication by improving behavioural and psychological support for this vulnerable population.

The work also highlights that treating behavioural problems in this way may have long term implications for the health care system. Using antipsychotics like this can increase costs for the NHS, as the significant side effects require treatment. Instead, improving educational support for families and schools, in place of using medication, may be more cost effective in the long run.

Sinead Brophy, Professor in Public Health Informatics at Swansea University, said “However, it must be noted that this is an analysis of the data. Any health decisions – including over whether to take medication or not – should be made with the input of a medical professional.”