New research published online in the Annals of Family Medicine on January 11, 2016 suggests opioid use may cause short-term improvement in mood, but long-term use for more than 30 days increases the risk of new-onset depression.

Prescription opioids, such as codeine, morphine and hydrocodone, relieve pain by reducing the pain signals sent to the brain, thereby controlling an individual’s emotional response to this natural feeling of discomfort.

The “Prescription Opioid Duration, Dose and Increased Risk of Depression in Three Large Patient Populations” study conducted by researchers from Saint Louis University, USA, analysed patient data from 2000-2012 from the Veterans Health Administration (VHA), Baylor Scott & White Health (BSWH), and the Henry Ford Health System (HFHS).

The study analysed more than 80,000 new opioid users aged between 18-to-80, who had no diagnosis of depression when commencing medication.

The study data revealed that among all three patient populations, longer use of opioids was linked to new-onset depression.

In an article published by Science Daily on January 12, 2016, entitled ‘Long-term opioid use associated with increased risk of depression’, study author, Associate Professor Jeffrey Scherrer, Saint Louis University, Missouri, USA said the “Findings were remarkably consistent across the three health care systems, even though the systems have very different patient characteristics and demographics.”

Furthermore, in an article posted by Live Science on January 20, 16, Scherrer cited the link with depression may be related to the lowered level of testosterone caused by opioids, which previous research indicates is associated with lower moods.

According to Beyond Blue, an Australian not-for-profit (NFP) supporting people living with depression and anxiety, currently three million Australians are experiencing anxiety or depression, and every day seven Australians commit suicide.

The relevance of this new research can therefore, not be underestimated by Australians battling mental health-related issues. Further research is required to determine how best to minimise the chance of depression induced by long-term opioid use, in a bid to reduce potential long-term physical and emotional pain.