A new study from Canada's McMaster University finds that infants born at an extremely low birth weight are more likely to be bullied later as children, and this significantly increases their odds for developing mental health problems as adults.
In fact, the more these individuals were bullied as children, the more likely they are to develop problems such as depression, anxiety, antisocial behavior, or attention-deficit/hyperactivity disorder (ADHD) as adults, according to new research at McMaster's Michael G. DeGroote School of Medicine.
Such children may be at greater risk for being bullied because of poor motor abilities, more anxiety, and struggles at school, the study said.
"This is the first study to fully illustrate the profound and long-lasting effects of bullying on the mental health of preterm survivors," said Dr. Ryan Van Lieshout, the senior author of the study and an assistant professor of psychiatry and behavioral neurosciences at McMaster.
"Their risk for anxiety disorders is especially high, particularly among those who are exposed to bullying on a regular basis."
The study involved babies who weighed 2.2 pounds (1 Kg) or less at their birth between 1977 and 1982 in Ontario. These individuals were later interviewed at the ages of eight, 22 to 26 and 29 to 36.
Their information was compared to normal birthweight babies of 5.5 pounds or more who were born in the same time span and interviewed at the same intervals.
The findings show that bullied low birth-weight children were nearly twice as likely to develop a mental health problem such as anxiety, depression, or ADHD by the time they were in their 20s. However, the risk was even higher for those who were bullied more often.
By the time these children reached their 30s, those who had been bullied as children were nearly three times more likely to have developed anxiety disorders such as obsessive-compulsive disorder, social phobia, and panic disorder. Rates were even higher for those bullied more frequently.
"Being bullied has a significant and lasting impact for those preemies, even into their 30s," said Dr. Kimberly Day, lead author of the study and Lawson Postdoctoral Fellow at the Offord Centre for Child Studies at McMaster.
"This has important implications for parents, teachers, and clinicians who need to be aware of the long-term effects of peer victimization on mental health. They need to watch out for bullying and intervene when possible."
The study is published in the journal Pediatrics.