(Reuters Health) - Children who are bullied during their pre-teen years may experience mental health issues like anxiety and depression, but a study of twins suggests that some victims may not experience lasting psychological problems.

Researchers examined data on about 11,000 twins born in England and Wales from 1994 to 1996. The youth completed assessments on their exposure to bullying when they were 11 and 14 years old, and they had mental health evaluations when they were 11 and 16 years old.

At age 11, kids who reported bullying were more likely than children who weren’t victims of peer victimization to report anxiety, depression, hyperactivity, inattention and conduct problems, the study found.

Some effects appeared to diminish over time, however. After five years, there no longer appeared to be a link between bullying and anxiety, but an association persisted for issues like cognitive disorganization and paranoid thoughts.

“Most children will get better,” said Judy Silberg, author of an accompanying editorial and a researcher at Virginia Commonwealth University in Richmond.

But it would be a mistake to assume all psychological problems associated with childhood bullying go away by age 16, Silberg said by email.

“There is a proportion of children who continue to have problems,” Silberg said. “Population studies demonstrate a persistent pattern of adverse effects, particularly in depression, anxiety and suicidal behavior as far as adulthood in those that have been bullied in childhood.”

For the current study, researchers focused on twins because this might help minimize the chances that genetics or other factors like home life are influencing the impact of bullying on kids, Jean-Baptiste Pingault of University College London in the U.K. and his colleagues note in JAMA Psychiatry.

Because reports of mental health problems appeared to lessen as years passed after bullying incidents occurred, the authors conclude that children may be resilient and able to rebound from this type of mistreatment and suggest that parents and schools should focus resources on fostering resilience.

The study wasn’t a controlled experiment designed to prove how long the effects of childhood bullying can last, however, and it’s possible certain children may still have long-term psychological problems after being victimized as kids, the authors acknowledge.

“The effects of bullying at age 11 on anxiety and depression at age 16 is what diminishes,” said Bonnie Leadbeater, a psychology researcher at the University of Victoria in British Columbia, Canada, who wasn’t involved in the study.

“You cannot interpret this as supporting a more general statement that the effects of bullying lessen over time,” Leadbeater said by email.

Because the study only assessed bullying and mental health at two points in time, it doesn’t provide a complete picture of how these two things may be related, Leadbeater said.

“Bullying may be episodic or chronic, and the limited assessment of bullying may severely underestimate the effects of chronic bullying on mental health and behavioral problems,” Leadbeater added.

SOURCES: bit.ly/2ybPQ60 and bit.ly/2zeYOj3 JAMA Psychiatry, online October 4, 2017.