Clinical Implications of Substance Use on Suicidality Among Youths

Both the American Psychiatric Association and the American Academy of Child and Adolescent Psychiatry have identified substance abuse as a top risk factor for suicide in youths. However, it is unclear how the association between substance use and suicidality varies among different substances and the number of substances used in this population. Using a nationally representative sample of 73,183 high school students in the US, we undertook a study to clarify the association between patterns of substance use and suicidality.

Data from the 2001 to 2009 Youth Risk Behavior Survey were used to analyze the correlation between lifetime use of 10 common substances of abuse (alcohol, cocaine, ecstasy, hallucinogens, heroin, inhalants, marijuana, methamphetamines, steroids, and tobacco) and 4 measures of suicidality (suicide ideation, suicide planning, suicide attempts, and severe suicide attempt requiring medical attention). The study controlled for multiple confounders, including sociodemographic factors and other health risk behaviors, such as depression, eating disorders, sexual activity, and interpersonal violence.

The key findings from the study indicate that:

     1. A history of substance use is a strong and independent risk factor for adolescent suicide ideation, and plans, and attempts-even after controlling for sociodemographics and other risk factors, such as depression, eating disorders, and interpersonal violence.

     2. Illicit substances (eg, heroin, methamphetamine, steroids, cocaine, inhalants, hallucinogens, ecstasy) have a higher association with sui-cidal thoughts and behaviors than do legalized substances, such as alcohol, tobacco, and marijuana. However, all substances were associated with an increased risk of suicide attempts (Table). For example, 27.5% of adolescents who reported heroin use at least once in their lifetime made a suicide attempt that required medical attention, compared with 1.6% of adolescents who reported never having used heroin (odds ratio [OR] = 23.6). In comparison, 4.1% of adolescents who reported marijuana use at least once in their lifetime made a suicide attempt that required medical attention, compared with 0.89% of adolescents who reported never having used marijuana (OR = 4.8).

     3. Among all substances surveyed, heroin, followed by methamphetamines, have the strongest association with suicide ideation, planning, attempts, and attempts requiring medical attention. Steroids also have a relatively strong association with suicide attempts compared with other substances. Hallucinogens have a relatively strong association with suicide attempts that require medical attention compared with other measures of suicidality.

     4. Adolescents who reported an increasing number of substances used in their lifetime had an increasing risk of suicide ideation, planning, attempts, and attempts that required medical attention (Figure). For example, 36.2% of adolescents who reported using 8 different types of substances in their lifetime have made a suicide attempt in the past year, with an average of 1.1 suicide attempts in the past year across the entire cohort. In comparison, only 4% of adolescents who reported using 1 substance in their lifetime have made a suicide attempt in the past year, with an average of 0.09 suicide attempts in the past year across this cohort of relatively substance-naive adolescents.

These findings suggest that users of different types of substances may have different risk profiles for suicide and that certain drugs may have specific psychological and behavioral sequelae that further increase suicide risk.

The major clinical implication from the study is that gathering information about the lifetime number and types of substances used by an adolescent can inform the assessment of suicide risk. Furthermore, understanding the substance use history may help determine the adolescent’s broader risk of health risk behaviors and associated mental illness. This can help guide clinical decision making regarding the level of mental health interventions an adolescent may require.

Disclosures:

Y. Wong is a Researcher in the department of applied psychology and human development at the University of Toronto in Toronto. Dr S. S. Wong is a Resident in the department of psychiatry at Massachusetts General Hospital and McLean Hospital in Boston. Dr Goebert is Professor in the department of psychiatry at the University of Hawaii John A. Burns School of Medicine in Manoa. Dr Hishinuma is Professor and Associate Chair of Research in the department of psychiatry at the University of Hawaii John A. Burns School of Medicine. The authors report no conflicts of interest concerning the subject matter of this article.

References:

Wong SS, Zhou B, Goebert D, Hishinuma ES. The risk of adolescent suicide across patterns of substance use: a nationally representative study of high school students in the United States from 1999 to 2009. Soc Psychiatry Psychiat Epidemiol. 2013 Jun 7; [Epub ahead of print]. doi:10.1007/s00127-013-0721-z.