"Psychosis" is a mental illness that makes it difficult to know what is real and what isn't. A person suffering from psychosis will usually have delusions -fixed beliefs about things that are not true, and/or hallucinations - hearing, seeing, smelling or feeling things that aren't really there. "Childhood onset" means that the person had the illness before the age of 14 (or, in America, it usually means before the age of 13). A person suffering from COP may have a very sudden onset of symptoms, for example, associated with going to secondary school, or they may have had developmental issues such as language delays or anxiety since they were very young, which gradually got worse. COP includes lots of different illnesses, including childhood onset schizophrenia, mood disorders with psychotic symptoms and psychosis in children caused by other medical conditions or treatment.
How many people have Childhood Onset Psychosis?
Psychosis in children is very rare. It is estimated that between 10 and 20 children a year are diagnosed with COP in the UK (not including those with psychosis caused by drug abuse, another medical illness or its treatment). It is likely to be a bit more common in children with ID than in children with normal intellectual ability, but it is much harder to diagnose psychosis in children with ID because of communication difficulties.
What Causes Childhood Onset Psychosis?
Sometimes the cause of COP can be found using blood tests, or scans such as EEGs or MRIs. It may be caused by something that is treatable, such as exposure to a toxin, a bad reaction to a medicine, an immune reaction, a seizure disorder, a tumour or a dietary problem. It may be caused by something that is not treatable such as certain genetic conditions, or damage to the brain. Doctors will usually check for these causes when the child first shows signs of psychosis. In other cases, there may not be a single cause. "Risk factors" are things that happen to a lot of people without causing psychosis, but they can increase the risk of psychosis when combined with other risk factors. Risk factors for COP include problems at birth that deprived the brain of oxygen, and difficulties during development in the womb, such as exposure to infection, toxins or malnutrition. Risk factors can be things that cause severe psychological stress such as having to leave the country you were born in, exposure to war, or death of a loved one. Certain genetic changes can be risk factors too.
Is there a cure?
If the psychosis remains unexplained after medical investigations such as blood tests and scans, there will not usually be a cure. But there are treatments, called antipsychotics. Children that develop psychosis may not respond to antipsychotics as well as adults, and may need to have high doses, or very strong drugs. But they often help a lot. Unfortunately, they can also cause side effects such as weight gain and diabetes. Certain drugs will be better for certain people than others, and it may take a while to find the best drug and dose. We hope to use genetic and other scientific research to help develop better treatments in the future.
The Genetics of COP
Psychosis that starts in childhood is thought to be more genetic than adult-onset psychotic illness. Genetic factors contributing to COP may be new mutations or they may be inherited from parents. If they are inherited, there may be a family history of illnesses such as schizophrenia, bipolar disorder, epilepsy, intellectual disability or autism. Genetic risk factors might not be very strong by themselves and might need to be 'brought out' byother risk factors. These types of genetic risk factors may 'skip a generation' so that both parents of a child with COP could be healthy, but a grandparent or a cousin might have mental illness. In some cases, genetic factors are very strong, and are thought to be a cause by themselves, rather than a risk factor. Finding a genetic cause of COP can mean a lot to families because they can understand why the child is mentally ill, and whether other people in the family may become mentally ill too. They could also reach out to other families with the same genetic cause, and receive support and advice.
We are trying to find people in the UK with childhood onset psychosis and look at their DNA to see if we can find a genetic cause. Because COP is so rare, it is not yet known how many people will have a genetic change that can be easily found. It is also not yet known what genetic changes can cause COP. Because of this, when a child is diagnosed with COP, doctors often do not test the DNA. In this study we will look at the DNA from people with COP (even if they are now adults), and also at DNA from their family members. We will bring together all the relevant scientific research and search for possible genetic causes. If we think we have found the cause, we can report this back to the family with the aid of a genetic counsellor who will help the family to understand what the genetic finding means for them. In many cases, we will not find something that we can be sure is a cause, but we will find genetic factors that are very interesting and need further research. These will not be reported to the family, but will help scientific research into illnesses such as COP, schizophrenia, epilepsy and autism.