Self-Injuring Behavior and Mental Illness in Opioid-Dependent Patients Treated with Implant Naltrexone, Methadone, and Buprenorphine in Western Australia

Factors associated with suicide in people who use drugs: a scoping review

BACKGROUND

Suicide is a significant contributor to global mortality. People who use drugs (PWUD) are at increased risk of death by suicide relative to the general population, but there is a lack of information on associated candidate factors for suicide in this group. The aim of this study was to provide a comprehensive overview of existing evidence on potential factors for death by suicide in PWUD.

METHODS

A scoping review was conducted according to the Arksey and O'Malley framework. Articles were identified using Medline, CINAHL, PsycINFO, SOCIndex, the Cochrane Database of Systematic Reviews and the Campbell Collaboration Database of Systematic Reviews; supplemented by grey literature, technical reports, and consultation with experts. No limitations were placed on study design. Publications in English from January 2000 to December 2021 were included. Two reviewers independently screened full-text publications for inclusion. Extracted data were collated using tables and accompanying narrative descriptive summaries. The review was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines.

RESULTS

The initial search identified 12,389 individual publications, of which 53 met the inclusion criteria. The majority (87%) of included publications were primary research, with an uncontrolled, retrospective study design. The most common data sources were drug treatment databases or national death indexes. Eleven potential factors associated with death by suicide among PWUD were identified: sex; mental health conditions; periods of heightened vulnerability; age profile; use of stimulants, cannabis, or new psychoactive substances; specific medical conditions; lack of dual diagnosis service provision; homelessness; incarceration; intravenous drug use; and race or ethnicity. Opioids, followed by cannabis and stimulant drugs were the most prevalent drugs of use in PWUD who died by suicide. A large proportion of evidence was related to opioid use; therefore, more primary research on suicide and explicit risk factors is required.

CONCLUSIONS

The majority of studies exploring factors associated with death by suicide among PWUD involved descriptive epidemiological data, with limited in-depth analyses of explicit risk factors. To prevent suicide in PWUD, it is important to consider potential risk factors and type of drug use, and to tailor policies and practices accordingly.

Impact of Pharmacological Treatments for Opioid Use Disorder on Mortality

The use of pharmacological treatments for opioid use disorders, including methadone, buprenorphine and naltrexone has been associated with a reduction in mortality compared with illicit opioid use. However, these treatments can also contribute significantly to the risk of death. The opioid agonists methadone and buprenorphine achieve clinical efficacy in patients with an opioid use disorder through suppressing craving and diminishing the effectiveness of illicit opioid doses, while the antagonist naltrexone blocks the action of opioids. Pharmacological differences between opioid pharmacotherapies then create different temporal patterns of protection and mortality risk, different risks of relapse to illicit opioid use, and variations in direct and indirect toxicity, which are revealed in clinical and epidemiological studies. Induction onto methadone and the cessation of oral naltrexone treatment are associated with an elevated risk of opioid poisoning, which is not apparent in patients treated with buprenorphine or sustained-release naltrexone. Beyond drug-related mortality, these pharmacotherapies can impact a participant's risk of death. Buprenorphine may also have some advantages over methadone in patients with depressive disorders or cardiovascular abnormalities. Naltrexone, which is also commonly prescribed to manage problem alcohol use, may reduce deaths in chronic co-alcohol users. Understanding these pharmacologically driven patterns then guides the judicious choice of drug and dosing schedule and the proactive risk management that is crucial to minimising the risk of death in treatment.