Examining the Impact of Psychopathological Comorbidity On the Medical Lethality of Adolescent Suicide Attempts

Background and Purpose: Suicide is the third leading cause of death for adolescents, as compared to the eleventh leading cause of death for all ages (CDC, 2008). The set of risk factors for adolescent suicide is complex and the understanding of how they are related with one another is not fully developed. Research suggests that medical lethality of a suicidal act is the main determinant of the likelihood of death following a suicide attempt (Nasser & Overholser, 1999), and it has been suggested that the characteristics of highly lethal suicide attempters may be similar to those of suicide completers (Beautrais, 2003; Brent, 1987). Therefore, studies differentiating the medical lethality of attempts can help to expand the knowledge base about risk factors for adolescent suicide. The primary aim of this study was to determine if various typologies of psychiatric diagnoses and patterns of comorbidity have different effects on the medical lethality of adolescent suicide attempts. The secondary aim was to determine if the relationship between psychopathological comorbidity and suicide attempt lethality differs across gender, age, and race.

Methods: Psychiatric evaluations were reviewed for all adolescents that presented to Children's Hospital Boston (CHB) from 2006 to 2010 for a suicide attempt (N=375). The Lethality of Suicide Attempt Rating Scale II (LSARS-II) was used to measure the dependent variable of lethality (Berman, Shepherd, & Silverman, 2003) and psychopathological comorbidity was measured using DSM-IV diagnoses. Statistical analysis used bivariate tests and OLS regression. Regressions were run for gender and age groups separately using the psychopathological comorbidity variables. Additionally, moderating effects were examined by creating interaction terms for gender and psychopathological comorbidity, as well as age group and psychopathological comorbidity.

Results: Bivariate results showed that attempters diagnosed with a substance abuse disorder had higher levels of suicide attempt lethality than those without the diagnosis. Additionally, having bipolar or mood disorder NOS in combination with either substance abuse alone or substance abuse and disruptive disorders had a significant positive relationship with suicide attempt lethality when compared to those without those comorbidity patterns. Substance abuse was the only diagnostic predictor of lethality in regression analysis, and no comorbidity patterns were predictive of lethality. However, once regressions were run separately for gender and moderating effects were taken into account, comorbid depressive and substance abuse disorders had a significant positive impact on suicide attempt lethality at trend level for males only. No depressive disorder comorbidity patterns were predictive of lethality for females. Age group was not predictive of lethality in regression analysis. African-American/Black race had a significant negative relationship with lethality.

Conclusions and Implications: Substance abuse was the only unique psychopathological predictor of adolescent suicide attempt lethality, suggesting the need for advancement of suicide risk assessments for adolescents receiving substance abuse treatment and policies that support the development and implementation of specialized adolescent dual diagnosis treatment facilities. Future research needs to focus on the development of effective treatment strategies with suicidal adolescent substance abusers, and further investigate suicidal behaviors of adolescents with comorbid bipolar and substance abuse diagnoses.