Researchers said treating chronic pain in those under the age of 25 is essential, but warned the regular use of painkillers could lead to over-reliance.
The study by scientists at St George’s, University of London, and the University of Liverpool, looked at anonymous medical records of 853,625 people aged two to 24.
Of the group, 115,101 were diagnosed with chronic pain, which is defined as pain that lasts more than three months.
Some 20,298 were given a repeat prescription for painkillers with no diagnosis, while 11,032 were both diagnosed and given a repeat prescription.
Patients were followed up for an average of five years after they turned 25.
In that time, researchers found 11,644 people had recorded a “substance misuse event”, 143,838 noted having poor mental health and 77,337 received at least one opioid prescription during the follow-up.
Professor Reecha Sofat, Breckenridge chair of clinical pharmacology and therapeutics at the University of Liverpool, said the findings, which have been published in The Lancet Regional Health – Europe, are “concerning” as those under 25 are “particularly vulnerable”.
“This means a regular use of painkillers to ease chronic pain may lead to an unintentional over-reliance on pain medication in adult life,” she added.
“Exploring when the right time is to refer these young people to specialised pain services for more targeted support will also be a vital factor when revamping pain management practice.”
It was highlighted patients with learning disabilities and autism were over-represented in the cohort receiving repeat prescriptions in the absence of a diagnosis for chronic pain, which researchers said could indicate overprescribing among a vulnerable group.
The team also said the trends identified in their work could be down to a number of factors, including that those prescribed painkillers from a young age may have had more severe or frequent pain.
"It’s clear that chronic pain management in young people needs to be optimised," Dr Andrew Lambarth, academic clinical fellow in clinical pharmacology and therapeutics at St George’s, University of London, said.
"We know under-treating pain can cause harm in both the short and long term, but it’s also essential to avoid over-reliance on medicines that could lead to dependence on prescription or non-prescription drugs in later life," Lambarth said.
"We now need to work with all healthcare providers to help them weigh up the risks and benefits of prescribing painkillers at a young age, and encourage the consideration of other recognised and effective non-drug management approaches."