NEW YORK (Reuters Health) - Sexually abused children are at increased risk of developing schizophrenia later in life, Australian researchers have found.
Although child abuse has been firmly tied to other mental health problems -- including depression, anxiety and suicide -- the link to psychotic illnesses has long been a subject of debate.
The new study shows sexual assaults more than doubled the odds that a child would develop schizophrenia as an adult -- from less than 1 in 100 (0.7 percent) in the general population to nearly 2 in 100 (1.9 percent) among the abuse victims.
The risk was higher still if the assault involved penetration or multiple perpetrators, or took place in the early teenage years.
Nearly one in five adults who had been raped by more than one person between ages 13 and 15 developed schizophrenia or another psychotic illness, Margaret Cutajar, of Monash University in Victoria, and colleagues found.
In their report, published in the Archives of General Psychiatry, they say the new results cannot prove a cause-and-effect relationship between the abuse and the later psychoses, but at the very least they may help point to a group of people who would benefit from professional help.
The researchers linked three decades' worth of data from police and medical examinations to a mental health register in the Australian state of Victoria.
Then they compared the rates of psychotic illnesses between people who'd been abused before age 16 and a control group of people drawn from voting records.
That design makes the study stand out, because the intersection between mental health problems and childhood abuse is a difficult area to investigate, said Mark Shevlin, a professor of psychology at the University of Ulster in Londonderry, Northern Ireland.
"Many of the studies to date have relied on retrospective recall of traumatic experiences," said Shevlin, who was not involved in the new research. And recall, he added, is not always trustworthy.
He stressed the findings don't necessarily mean the abuse triggers later psychosis directly, because it may reflect other risk factors such as poverty or a difficult family situation.
Still, he said, children who experience sexual assaults, especially by a family member, may become anxious and withdrawn and perceive the world as a threatening place.
"These things could maybe explain things like paranoid beliefs," said Shevlin. "Environmental factors are obviously very important in the development of serious health problems."
Craig Steel, an expert in psychological trauma at Reading University in the UK, said the new paper made a strong case for going beyond drugs when treating people with schizophrenia.
Although both US and UK government guidelines recommend using cognitive behavioral therapy in addition to medication, he said, psychiatrists tend not to focus on patients' personal histories.
"At the very least the study adds weight to the fact that, as clinicians when we are confronted with people with schizophrenia, trauma assessment should be a routine part of our practice," Steel told Reuters Health.
And kids aren't the only ones to get psychological scars from sexual assaults, although they may be particularly vulnerable.
In a recent study of Danish women, for instance, Shevlin found those who attended rape centers were many times as likely to receive a diagnosis of psychosis later on.
"It appears this association is evident in adults as well, although most of the work has been done in children," he said.
SOURCE: http://link.reuters.com/hak53q Archives of General Psychiatry, November 1, 2010.