A "substantial percentage" of suicide victims test positive for
alcohol and other drugs but, except for opiates, the proportion of positive
tests is similar in those who died by suspected intentional overdose and those
who killed themselves by other means, according to a report in the November 24
Morbidity and Mortality Weekly Report (MMWR).
That, said researchers from the Centers for Disease Control and Prevention
(CDC), "suggest[s] that use of alcohol or other drugs might contribute
substantially to suicides overall, regardless of the cause of
More complete reporting of toxicology test results might help in the
development of better suicide-prevention interventions, said the researchers."
Such data can be enhanced by uniform, comprehensive, toxicology testing
practices on a state and national
While links between suicide and substance use are well known, the CDC drew
on new data about 5,550 victims tested out of 7,277 suicides from 13 states
reported in 2004 to the National Violent Death Reporting System (NVDRS).
Toxicology testing after suicide deaths varied widely among the states
reporting, from 25.9 percent in Oregon to 97.7 percent in Virginia. Local
policy and preferences of individual coroners or medical examiners seem to
decide which suicide cases are tested for substance traces. Those officials
may more frequently target cases in which alcohol or drugs are suspected to
have caused or contributed to the deaths, but conduct toxicology tests less
often when the cause of death seems clear and unrelated to substance use.
Overall, positive toxicology tests of people who committed suicide were
recorded for alcohol (33.3 percent), opiates (16.4 percent), cocaine (9.4
percent), marijuana (7.7 percent), and amphetamines (3.9 percent). Opiates
included both heroin and prescription drugs. The reports did not include data
on amounts or chronicity of substance use.
"These percentages are much higher than you'd find in the general
population," said J. Raymond DePaulo, Jr., M.D., the Henry Phipps
professor and chair of the Department of Psychiatry and Behavioral Sciences at
Johns Hopkins University School of Medicine, in an interview with
"Poisoning" was defined as suspected intentional overdose.
Similar percentages of poisoning-suicide and nonpoisoning-suicide victims
tested positive for alcohol or other drugs, with the exception of opiates:
31.6 percent of poisoning suicides versus 33.6 percent of nonpoisoning cases
were positive for alcohol, 5.8 percent versus 3.3 percent of cases were
positive for amphetamines, and 8.3 percent versus 9.7 percent were positive
for cocaine. The exception was opiates, for which 39.8 percent of those who
killed themselves by poisoning tested positive, compared with only 8.2 percent
of nonpoisoning victims.
"Associations with opiates may in part reflect the use of these drugs
in people with chronic pain or serious illness, both of which are associated
with increased suicide risk," David Gunnell, M.B., Ph.D., professor of
epidemiology in the Department of Social Medicine at the University of Bristol
in England, told Psychiatric News. Gunnell is an expert on the
epidemiology of suicide.
"Substances have a role in suicides, from several angles," said
DePaulo. "Depression leads to alcohol use, and alcoholism leads to
depression. In people with depression, alcoholism not only worsens the
depression but makes relapse into depression more likely even after recovery.
A significant minority `pre-dose' themselves with alcohol, using its
disinhibiting effects to make them less likely to back out of their decision
to kill themselves."
This use of alcohol and drugs to overcome barriers to suicide may explain
why rates of substances found in suicide victims' bodies are similar,
regardless of the means of death.
The NVDRS collects information on all violent deaths—homicides,
suicides, unintentional deaths by firearms, legal interventions, or deaths of
unknown intent from Alaska, Colorado, Georgia, Maryland, Massachusetts, New
Jersey, North Carolina, Oklahoma, Oregon, Rhode Island, South Carolina,
Virginia, and Wisconsin.
The system is not comprehensive, however. Even though substance abuse is a
known risk factor for suicide, none of the 13 states performs routine drug or
alcohol screenings on all suicide victims.
Inconsistent testing limits the value of the NVDRS data, said Gunnell."
The data can only really be evaluated fully for those states where a
high proportion of suicides were tested. In the states where only a small
percentage were tested, the high yields likely reflect targeting of testing at
those where drug or alcohol misuse were already considered potentially
The NVDRS also did not report on toxicology results for psychotropic drugs.
A separate study of 333 consecutive suicides in Mobile, Ala., from 1990
through 1998 found that 20 percent of the victims had traces of
antidepressants in their systems, which might be considered low today.
A study of forensic data from a subset of young suicide victims in Utah who
killed themselves between 1996 and 2002 found that alcohol and methamphetamine
were the most common substances found in their blood or urine. The low levels
of antidepressants found may have indicated either undiagnosed mental illness
or failure to take prescribed medications, the Utah researchers suggested.
"It's important that future studies screen for psychotropics and
antidepressants" in the bodies of suicide victims, said DePaulo. That
would better indicate treatment or compliance patterns.
More comprehensive toxicology testing linked with demographic data could
offer clues into how suicide trends change over time and geography, said the
MMWR report. Such information could help target populations at risk for
suicide and focus preventive measures on those groups.
"Toxicology Testing and Results for Suicide Victims—13
States 2004" is posted at<www.cdc.gov/mmwr/preview/mmwrhtml/mm5546a1.htm>.▪