Microcephaly may be the most visible suspected effect of the Zika outbreak in Latin America, but it likely won’t be the last.
According to researchers, similar viruses have been tied to the development mental illnesses, including schizophrenia, ADHD, and bipolar disorder.
In utero exposure to Zika by itself likely won’t be enough to start the cascade of changes that leads to mental illnesses—it’s one factor of many that scientists will consider. But based on previous research into similar viruses, virologists and neuroscientists are anticipating a rash of autism, epilepsy, ADHD, and schizophrenia to result from the current outbreak in Latin America and the Caribbean.
Here’s Donald McNeil, Jr., interviewing Dr. Ian Lipkin, a professor of epidemiology at Columbia University,for the New York Times :
Among children in Latin America and the Caribbean, “I wouldn’t be surprised if we saw a big upswing in A.D.H.D., autism, epilepsy and schizophrenia,” he added. “We’re looking at a large group of individuals who may not be able to function in the world.”
Viruses like rubella, herpes, and influenza can all affect fetal development, though the strength of the link for various mental illnesses hasn’t been settled. Some studies have tied high rates of schizophrenia to historical pandemics, while others have found that the effects may not be as widespread. Still other studies of mice have suggested that the timing of that exposure appears to drive which mental illness develops in later adults.
The forecasts for the effects caused by Zika are based on earlier outbreaks like the 1964-1965 rubella outbreak, which led to defects in up to 90% of children whose mothers were infected in the first trimester. Those children were born with a range of disabilities, from deafness to with heart defects or mental disabilities. Together, they were known as congenital rubella syndrome. Today, thanks to vaccines, congenital rubella syndrome is largely a thing of the past.
A Zika vaccine is in the works, but until one is released, doctors and epidemiologists will be watching for lingering effects of the virus as the affected children grow older.