New research from the University of Montreal and the CHUM Research Center suggest that people who use stimulants such as cocaine and amphetamine have a nearly two-fold greater likelihood of suicidal behavior amongst people who inject drugs.
Drug addiction had already been identified as a major risk factor for suicide, and it is in fact the cause of ten percent of deaths among drug users. The data from this groundbreaking study could help develop and evaluate more appropriate suicide prevention efforts in this highly vulnerable population.
"We know that substance use is associated with the risk of suicide attempt and completed suicide. However, there are many different profiles of drug users. The data available until recently did not allow identifying the substance use patterns most at risk. We wanted to know who among substance users were actually more likely to attempt suicide," researcher Didier Jutras-Aswad said in a statement.
For the study, researchers collected and analyzed data of more than 1,200 people who inject drugs from the HEPCO Cohort to examine the individual and contextual factors associated with hepatitis C infection. The HEPCO participants were 18 years or older and had injected drugs in the past six months.
Twice a year, the participants in the study completed a questionnaire to better understand their drug use habits and assess certain markers of mental health. The median follow-up was four visits. They were specifically asked if they had attempted suicide in the past six months, but also about the nature and frequency of their consumption. Several substances were evaluated in detail, including cocaine, amphetamines, opioids, cannabis, alcohol, and sedative-hypnotics available illegally on the street (i.e., barbiturates and benzodiazepines).
The findings indicate that suicide attempts are most common among people who inject drugs. But researchers also found that chronic and occasional use of stimulant drugs such as cocaine and amphetamines was associated with nearly two-fold greater odds of reporting an attempt than the use of other drugs to report a suicide attempt.
They did not observe the same positive association with other substances, including opiates, which are nevertheless regarded as among the most damaging to health and psycho-social wellbeing.
Researchers said a set of neurobiological, behavioral and social differences between stimulant users and opiate users could explain these findings. Stimulant users are more vulnerable because they are more impulsive and characterized by changing moods. The researchers also point out that cocaine addiction treatments are virtually nonexistent - drug treatment programs are often structured around opiates or alcohol.
"Our study addresses a number of important issues that could change practice. While it confirms that drug use itself represents a significant risk for suicidal behavior, it identifies cocaine and amphetamine users as a higher-risk population," said Jutras-Aswad.
The study suggests that there's a need for more effective intervention and prevention programs tailored to this target population.
The findings are detailed in the online journal Drug and Alcohol Dependence.
