While patients often suffer the two conditions, this is the first study to review all relevant research in the field and show that depression may actually trigger back pain.
The new study, published in Arthritis Care and Research, analysed data from 11 international studies including a total of 23,109 participants who were not currently experiencing back pain. It found people with symptoms of depression had a much higher risk of developing low back pain in the future compared with those showing no symptoms of depression.
The risk of low back pain also increased in patients with more severe levels of depression, and was not impacted by whether depression was self-reported or clinically diagnosed.
Dr Paulo Ferreira from the University of Sydney’s Faculty of Health Sciences said the research suggests that up to 61,200 cases of low back pain in Australia are partially attributed to depression.
“Low back pain is a debilitating condition, particularly when coupled with other health conditions, so I hope this discovery will lead to better treatment in the future,” said Dr Ferreira.
“When patients come to us with both back pain and depression their cases are much more complex. They don’t respond to treatment in the same way as patients who only experience back pain - they take much longer to recover and treatment can be expensive.
“Our study suggests we would have much better outcomes if we treated depression and back pain simultaneously, but this would require health professionals from different fields to work together more closely.”
Other studies estimate that up to 48 per cent of people with back pain experience symptoms of depression, however to date, scientists cannot agree on the cause.
The researchers acknowledge the current study could not account for potential influences such as genetics and shared environmental factors.
Lead author, physiotherapist Marina Pinheiro said further research needed to explore the causal relationship between the two conditions.
“While this study tells us there is definitely a link between depression and back pain, it doesn’t tell us why,” said Ms Pinheiro, PhD candidate in the Faculty of Health Sciences.
“It could be because people with depression often have lower levels of physical activity and poor sleep, or due to issues with neurotransmitters which impact both mood and pain thresholds.”
The research team are carrying out further studies into the impact of genetics, with their research on twins suggesting some people may be genetically pre-disposed to both conditions.