Substances involved in suicidal overdoses in a major metropolitan area

Background/Purpose Suicide is one of the leading causes of non-natural death in San Diego County, and overdoses make up one-fifth of all suicides. The purpose of this study is to quantify the actual substances used in suicidal overdoses. Methods The San Diego County Medical Examiner's database was examined for cases involving suicides by drug overdose that occurred from 2006 through 2010. The substances that contributed to the death were extracted from the cause of death variables. Results/Outcomes From 2006 through 2010, the San Diego County Medical Examiner investigated 386 cases of suicide by drug overdose. These involved 108 unique substances, mentioned a total of 960 times, for an average of 2.49 substances per decedent. The most common substance mentioned was alcohol (19% of cases), followed by diphenhydramine (14.5%), hydrocodone (13.7%), quetiapine (12.4%), and acetaminophen (11.7%). Only 98 cases (25%) mentioned just one substance, most commonly diphenhydramine (11 cases, 2.8%). According to drug categories, opiates were the most commonly mentioned (38% of cases), followed by tranquilizers (30%) and antidepressants (29%). Conclusions In contrast to unintentional drug overdoses which very often involve illicit substances, suicidal overdoses often involve over the counter medications or legitimately obtained prescription drugs. Because suicides are very likely to involve multiple substances, it can be difficult to determine which drug contributed most to the death. Other possibilities are that the drug was on board incidentally in therapeutic quantities, or that it contributed to the behavior leading to the suicidal act.