It begs the question on funding for research, when in this recent article interconnections are touched on:

...Another area of concern, which is still under the radar, is the connection between opioid addiction and gun violence. According to the study, published in Drug and Alcohol Dependence, opioid addicts are more prone to carry or become victims of gun violence than alcohol-dependent individuals. The study was conducted in Massachusetts and found that the rate of gun possession is more than twice among opioid-dependent respondents than the rate of regular residents. Majority of the addicted population have carried gun for self-protection and have involved in gun-related violence. This is especially concerning as Massachusetts presents the least number of gun-related casualties in the nation. This is another tier of threat that opioid-addiction presents to our society. Read more