Genetic Testing Reveals DNA Changes in Children With Early-Onset Psychosis
While children are known for their active imaginations, it’s extremely rare for them to have true psychotic symptoms.
But two unusual case studies, both of children under seven, prompted a new investigation that has identified a shared genetic component linking many cases of what is known as early-onset psychosis.
The authors of the study, including Dr. Joseph Gonzalez-Heydrich, a psychiatrist at Boston Children’s Hospital and his colleagues Dr. David Glahn and Dr. Catherine Brownstein, now recommend chromosomal microarray testing for any children showing psychotic symptoms.
What is chromosomal microarray testing?
Chromosomal microarray testing is a diagnostic tool that looks for missing (deleted) or extra (duplicated) chromosomal segments, often called copy number variations (CNVs). These changes can be small or significant in scope, and can include duplications of entire chromosomes, such as in Down syndrome, where there is an extra copy of chromosome 21.
The study has been published in the American Journal of Psychiatry.
Ghosts and aliens
Gonzalez-Heydrich’s investigation began with this study of two young patients presenting with psychotic symptoms. A six-year-old boy began hearing voices coming from the walls and the school intercom telling him to hurt himself and others. He saw ghosts, aliens in trees and colored footprints. Gonzalez-Heydrich prescribed antipsychotic medications and the frightening hallucinations stopped. Another child had hallucinations with monsters, a big black wolf, spiders and a man with blood on his face at age four.
Chromosomal array testing revealed that both children had CNVs.
Gonzalez-Heydrich then expanded the chromosomal array testing to a larger cohort. The study involved 137 children, all with early-onset psychosis. More than 70% of the children in the study had begun experiencing psychosis before the age of 13. Twenty-eight percent met formal criteria for schizophrenia, having persistent and unrelenting symptoms. All underwent systematic testing for CNVs — and a surprising 40 percent tested positive. The prevalence of CNVs were as common as they are in children with autism, who are often screened for these DNA duplications and deletions in the clinic. In many cases, the CNVs identified had also been linked to other psychiatric and neurodevelopmental disorders.
“Our findings make a strong case for chromosomal microarray testing in any child or adolescent diagnosed with psychosis,” says Brownstein, who co-led the study with Dr. Elise Douard at the University of Montreal . “Testing often brings closure for families, and could help advance research.”
Difficulties in diagnosis
Many of the children in the study had comorbid disorders that had made diagnosis of early-onset psychosis challenging:
- Just over a third of children in the study had a diagnosis of autism spectrum disorder
- 12 percent had intellectual disability
- 18 percent had a history of seizure
Families are often relieved to learn that their child’s psychotic symptoms have a biological component. Their child’s psychosis may have been misdiagnosed, explained away as a normal developmental phase, attributed to stresses like being bullied or even blamed on bad parenting.
“Many parents feel like they are put under the microscope, or are even accused of triggering their child’s symptoms,” says Gonzalez-Heydrich. “It parallels what happened with autism a generation ago.”
Many clinicians may be reluctant to diagnose children with psychosis, hoping to avoid the stigma associated with such a diagnosis at an early age. However, the authors believe that finding a CNV might justify a trial of antipsychotic medications to see if they help.
“The longer psychosis goes untreated, the harder it is to treat later on,” says Glahn. “If we can treat it earlier and appropriately, the child will likely do better over their lifetime.”
What does psychosis look like in children?
In some children, psychotic symptoms come and go. Psychosis can appear when a child is under stress, angry, very depressed, or having mood swings. But in children with true schizophrenia, symptoms are persistent and extreme. This is very rare in children under 10 but becomes less rare in adolescence and early adulthood. For perspective, schizophrenia affects just one to two percent of the general population, including adults.
Many children have behaviors that can seem like psychosis, like having an imaginary friend. But true psychosis is distressing to children and outside their control, say Glahn and Gonzalez-Heydrich.
“It’s not simply the child thinking someone’s talking about them because they’re socially anxious,” says Gonzelez-Heydrich. “It’s multiple voices criticizing them, scaring them or telling them to do bad things. Or feeling that strangers are staring at them, planning to do them harm.”
The benefits of diagnosis
Finding a CNV in an affected child can not only encourage treatment but can help make the child’s family aware so that they can also investigate their own risk level. Some CNVs can also cause medical complications like seizures, heart problems, or weakened blood vessels that can be watched and treated. Family members found to have CNVs may also be at risk for such medical problems, even if they don’t have behavioral symptoms.
Brownstein, who is scientific director of the Manton Center for Orphan Disease Research at Boston Children’s and a member of the Division of Genetics and Genomics, oversaw the genetic testing. She notes that finding a CNV can help parents connect with other families for reassurance and support. Also, once a CNV is found, scientists can study what the lost or duplicated genes do. This could lead to a better understanding of the origins of early psychosis and possibly to better antipsychotic drugs, which have changed little since the 1950s.
“We don’t have medications tailored to CNVs yet,” Brownstein says. “But when parents get together, they can organize and identify research devoted to their particular CNV. We can study their children as a group and identify effective treatments a lot faster.”
This article is a rework of a press release issued by Boston Children's Hospital. Material has been edited for length and content.
Reference: Brownstein CA, Douard E, Mollon J, et al. Similar rates of deleterious copy number variants in early-onset psychosis and autism spectrum disorder. AJP. 2022:appi.ajp.21111175. doi: 10.1176/appi.ajp.21111175