Using painkillers long term may contribute to poor mental health and substance abuse

The long-term use of painkillers from a young age may be linked to an increased risk of poor mental health later in life, according to a new study published in The Lancet Regional Health – Europe.

The research, carried out by scientists at the University of Liverpool and St George’s, University of London, found that children and young adults under 25 years of age who have chronic pain – defined as pain that lasts more than three months – were 29% more likely to have a mental illness in adulthood. Those who had chronic pain and were also given a prescription painkiller were 46% more likely to have a mental illness in adult life and had an 82% higher risk of substance misuse.

The study also found that having a diagnosis of chronic pain and being prescribed a painkiller at a young age led to more prescription opioid use in later life.

The researchers looked at anonymous medical records of 853,625 people aged two to 24, of whom 115,101 were diagnosed with chronic pain. Of these, 20,298 were given a repeat prescription for painkillers with no diagnosis, while 11,032 were both diagnosed and given a repeat prescription.

Children with learning disability more likely to have repeat prescriptions

The patients were followed up for an average of five years after the age of 25. In total, 11,644 people were identified as having a substance misuse event, 143,838 were noted as having poor mental health and 77,337 received at least one opioid prescription during follow-up.

Results were adjusted for gender, deprivation, smoking status, alcohol use, BMI, year of birth, prior mental illness and prior substance misuse.

The researchers acknowledge that there could be a number of explanations for the findings – for example that young people who received painkillers may have had more severe or frequent pain.

The team also found that children and young people with intellectual disability and autism spectrum disorder were over-represented among participants receiving repeat prescriptions for pain relief in the absence of a chronic pain diagnosis. They say this may indicate overprescribing in this already vulnerable group.

Need to weigh up risks and benefits

Chronic pain is relatively common amongst children – 8% of children experience intense and frequent pain, the researchers said. Most research investigating chronic pain and long-term painkiller use has focused on adults, however.

Dr Andrew Lambarth, academic clinical fellow in clinical pharmacology and therapeutics at St George’s, University of London said: “It’s clear that chronic pain management in young people needs to be optimised. We know undertreating 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.

“We now need to work with all health care 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.”

Professor Reecha Sofat, Breckenridge chair of clinical pharmacology and T=therapeutics at the University of Liverpool, said: “These trends are concerning as under 25s 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. 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.”

This study was supported by funding from UCLH Charity, UKRI, Versus Arthritis (via the Consortium Against Pain InEquality (CAPE): The Impact of Adverse Childhood Experiences on Chronic Pain and Responses to Treatment), and the Wellcome Trust.