Widespread access to opioid agonist treatment (OAT) can reduce the risk of suicide by 35% among people with opioid use disorder, according to a new study published in Addiction.
Researchers led by the National Drug and Alcohol Research Centre (NDARC) at UNSW Sydney said their findings suggest the OAT program in NSW averted an estimated 338 suicides between 2001 and 2020.
"Our study underscores the critical role of OAT, including methadone and buprenorphine, as life-saving medications and a key public health intervention in reducing suicide risk among people with opioid use disorder," said Dr Thomas Santo Jr, a Postdoctoral Research Fellow at NDARC and lead author of the study.
"It also highlights the urgent need to expand access to OAT – both locally and globally – given the potential to reduce suicide-related deaths in these individuals by more than one-third."
Global estimates for attempted suicide prevalence in people with opioid use disorder range from 20% to 50%, and around one in 12 deaths in this population are due to suicide.
OAT is widely recognised as the most effective treatment for reducing overdose deaths in people with opioid use disorder, but its role in suicide prevention has been less clear.
To address this, Dr Santo Jr's team analysed data from nearly 47,000 individuals who received OAT in community and prison settings in NSW between 2001 and 2017. They then estimated the number of suicides prevented by the OAT program over a 20-year period.
Based on their modelling, access to OAT was estimated to have averted 338 suicides – 325 in the community and 13 in prison – between 2001 and 2020.
This corresponds to 35% of suicide deaths averted in the community and 27% in prison settings among people with opioid use disorder.
"Without an OAT program in NSW, we estimate that nearly 960 suicides could have occurred among people with opioid use disorder between 2001 and 2020. Instead, with OAT in place, 338 of these suicides were prevented, leading to a gain of 2,704 life-years—highlighting its life-saving impact," said Dr Santo Jr.
"Specifically, our study indicates that OAT provision was linked to a prevention of 2% of all suicides that occurred in NSW during the same period—a modest impact, but still crucial to achieving the WHO and UN Sustainable Development Goal targets to cut suicide rates by one-third by 2030.
"Given its proven effectiveness in reducing suicide risk, particularly compared to many other interventions, expanding access to OAT should be a priority in broader suicide prevention strategies."
Dr Santo Jr added that access to OAT could also reduce health inequities in NSW, as individuals experiencing homelessness, those from lower socio-economic backgrounds, and Aboriginal communities have disproportionately high rates of opioid use disorder.
"A population-level intervention like OAT can make a substantial difference in preventing suicide among marginalised communities, particularly given the structural and systemic barriers they face in accessing mental health and suicide prevention services."
One limitation is that these findings are based on the OAT program in NSW and may not apply to all programs or communities. The high coverage rate, with nearly 90% of people with opioid use disorder having received OAT at least once, is likely a key factor in the program's widespread impact and its effect on suicide prevention in this setting.
