Classifying Drug Intoxication Deaths as Suicides

Compared to deaths by overtly violent methods, such as gunshot or hanging, drug intoxication deaths are more likely to be classified as “undetermined intent” and less likely to be classified as suicides. A suicide note, history of suicide attempts, or evidence of a mood disorder increase the likelihood that drug intoxication deaths are classified as suicides.

Researchers used data from the 17 states participating in the National Violent Death Reporting System (NVDRS) between 2011 and 2013. NVDRS is a surveillance system that draws on data from death certificates, law enforcement records, and medical examiner and coroner records to provide detailed information about suicide and other violent deaths. Researchers found that, compared to drug intoxication deaths, gunshot or hanging deaths were 41 times more likely to be classified as suicides. The presence of a suicide note, history of suicide attempts, or diagnosis of a mood disorder played a more important role in the classification of drug intoxication deaths as suicides than gunshot or hanging deaths. 

Deaths by drug intoxication appear to require a higher level of psychological evidence to be classified as suicides than deaths by more overtly violent methods. Because less than one-third of suicide cases include record of a mood disorder, prior suicide attempt, or authenticated suicide note, suicide by drug intoxication may be profoundly underreported. The researchers suggested that underreporting of suicides by drug intoxication could affect the use of data for suicide prevention planning and evaluation.

Rockett, I. R. H., Caine, E. D., Connery, H. S., D’Onofrio, G., Gunnell, D. J., Miller, T. R., . . . Nolte, K. B. (2018). Discerning suicide in drug intoxication deaths: Paucity and primacy of suicide notes and psychiatric history. PLOS One, 13(1), e0190200. https://doi.org/10.1371/journal.pone.0190200