The negative social, physical and mental health effects of childhood bullying are still evident nearly 40 years later, according to new research.
The study by King's College London is the first to look at the effects of bullying beyond early adulthood.
The findings come from the British National Child Development Study which includes data on all children born in England, Scotland and Wales during one week in 1958.
The new research studied 7,771 children whose parents provided information on their child's exposure to bullying when they were aged 7 and 11. The children were then followed up until the age of 50.
"Our study shows that the effects of bullying are still visible nearly four decades later. The impact of bullying is persistent and pervasive, with health, social and economic consequences lasting well into adulthood," said Dr Ryu Takizawa, lead author of the paper from the Institute of Psychiatry at King's College London.
Just over a quarter of children in the study (28 per cent) had been bullied occasionally, and 15 per cent bullied frequently - similar to rates in the UK today, researchers said.
Individuals who were bullied in childhood were more likely to have poorer physical and psychological health and cognitive functioning at age 50.
Individuals who were frequently bullied in childhood were at an increased risk of depression, anxiety disorders, and suicidal thoughts.
Individuals who were bullied in childhood were also more likely to have lower educational levels, with men who were bullied more likely to be unemployed and earn less.
Social relationships and well-being were also affected. Individuals who had been bullied were less likely to be in a relationship, to have good social support, and were more likely to report lower quality of life and life satisfaction.
"We need to move away from any perception that bullying is just an inevitable part of growing-up," said Professor Louise Arseneault, senior author, also from the Institute of Psychiatry at King's.
"Teachers, parents and policy-makers should be aware that what happens in the school playground can have long-term repercussions for children.
"Programmes to stop bullying are extremely important, but we also need to focus our efforts on early intervention to prevent potential problems persisting into adolescence and adulthood," Arseneault said.
The harmful effect of bullying remained even when other factors including childhood IQ, emotional and behavioural problems, parents' socioeconomic status and low parental involvement, were taken into account, researchers said.
The study is published in the American Journal of Psychiatry.