Substance Use Linked to Increased Suicide Risk Among Mental Health Clients

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Substance use, including alcohol, tobacco, stimulants and hallucinogens, was strongly linked to increased suicide risk among patients seeking mental health and addition (MHA) services, with hallucinogen and amphetamine/methamphetamine users exhibiting the highest levels of suicide risk.

“Substance use, alongside depression, is a significant risk factor for suicidal ideation, attempts and completed suicide,” wrote a team of investigators including JianLi Wang, PhD, professor within the Department of Community Health and Epidemiology at Dalhousie University in Nova Scotia, Canada. “Additionally, frequent and prolonged substance use often results in substance use disorder (SUD), which is characterized by compulsive use, significant impairment or distress, negative effects on health and daily life10 and a notably amplified risk of suicide.”

In Canada, suicide claims approximately 4,500 lives each year, which amounts to an average of 12 deaths per day, and is the second leading cause of death among people aged 15 to 34 years. Additionally, suicide rates rose from 2.7% to 4.2% during the COVID-19 pandemic.

To determine the prevalence of suicide risk among those seeking MHA services, as well as to assess the relationship between suicide risk and substance abuse, investigators assessed data from 22,500 clients from an intake program created by the Department of Health and Wellness of Nova Scotia. The clients, aged 19 to 64 years, contacted MHA intake from 2020 to 2021. They were evaluated for suicide risk during the initial intake assessment, which included any past suicide attempt and/or suicidal ideation at any point within the 2 weeks leading up to the interview.

Substance use included alcohol, inhalants, opioids, stimulants, tobacco and hallucinogens. Investigators also included data on the frequency of use, route of administration, duration, last use and the impact of the substance on functionality.

Findings revealed that 25.25% had attempted suicide at some point in their lives, with 34.14% showing mild suicide risk and 4.08% having moderate/high suicide risk.

People who used hallucinogens had the highest incidence of mild and moderate/high suicide risk (61.3% and 12.9%, respectively), followed by those who used amphetamine/methamphetamines (47.6% and 13.3%, respectively) and sedative/hypnotics (47.2% and 8.9%, respectively). Clients who reported currently using stimulants and hallucinogens had an increased risk of moderate/high suicide risk compared with those who did not currently use these substances. Other substances that increased the odds of mild suicide risk included alcohol and tobacco.

Unexpectedly, cannabis, cocaine, opioid and polysubstance use were not linked to an increased risk of suicide.

The investigators said the large sample size of patients coupled with the variety of kinds of substance use evaluated strengthened the study. It was the first study to determine the link between suicide risk and substance abuse while controlling for mental health problems among this population.

However, omitting the quantity of substance use, due to missing data, was considered a limitation because it hampered the understanding of how the amounts of substance use can impact the risk of suicide. They also noted the possibility of social desirability bias, as some patients may not have been honest about their suicide risk and substance use. Additionally, patients who completed suicide were not included in the study.

“This result underscored the importance of considering substance use patterns when assessing suicide risk and highlighted the need for targeted interventions and preventive measures for individuals engaging in substance use,” investigators concluded. “Future interventional studies are needed to identify and evaluate effective strategies for reducing substance use and suicide risk among clients of MHA central intake.”