Angst MS, Lazzeroni LC, Phillips NG, Drover DR, Tingle M, Ray A, Swan GE, Clark JD.
Anesthesiology. 2012 Jul;117(1):22-37.
Comment: This is a twin study to look at the genetic contribution to opioid effects. I would recommend perusing the full article (which may be available here) if you work with opioid users, as the results are really intriguing. Directly relevant to overdose is the finding that 30% of the respiratory depression effect is genetic. Furthermore, respiratory depression increases with age (that is, older opioid users tolerate higher CO2 concentrations), more so among men.
I take two messages from this paper:
1) We've known for years that people who overdose are highly likely to overdose again, but we don't understand all of the reasons why. Is it behavioral (e.g. polydrug use, short stints of abstinence) or physiologic (e.g. lung disease, liver disease, etc)? Now we know that part of the reason is genetic.
2) While I still suspect there are ways to reduce the risk of overdose by changing patterns of drug use, some of that risk is genetic and unlikely to be affected by education.