Alcohol and drugs play substantial roles in firearm violence in the United States, including both homicide and suicide. As evidenced by the case-control study by Hohl and colleagues1 in this issue of JAMA Internal Medicine, the relationship occurs on multiple levels. The study found that measures of individual, family, and neighborhood substance use—particularly for illicit drugs—increased the risk of becoming a victim of firearm homicide among Philadelphia adolescents. These findings contribute to a larger body of research suggesting that there are multiple direct and indirect pathways by which alcohol and drugs can increase the risk of firearm homicide and suicide. Delineation of such pathways is crucial for interventions to prevent firearm violence.
Hohl et al1 studied adolescents in Philadelphia aged 13 to 20 years. Compared with other age groups, adolescents and young adults are at highest risk of both misusing substances and perpetrating and becoming victims of firearm homicide. In 2014, 44% of adolescents and young adults aged 12 to 25 years reported binge drinking and 31% reported using an illicit drug in the past month, compared with 23% and 8% of those aged 26 years or older.2 In the same year, there were 4254 firearm homicides among those younger than 26 years, accounting for 39% of all firearm homicides in the US. About 70% of all homicides in the US are committed with firearms, and the proportion is higher among youth. During Hohl et al’s1 2010 to 2012 study period, 98% of Philadelphia homicide victims ages 13 to 20 years were killed with a firearm, compared with 86% nationwide for that age range.1 The higher proportion of firearm homicides among adolescents in Philadelphia may be owing to a lower minimum age for legal handgun possession in Pennsylvania (18 vs 21 in some states). In addition, the city’s high rate of violent crime may prompt more youth at high risk to carry guns.
Prevalence studies show a clear correlation between substance use and perpetrating and becoming a victim of firearm violence. Between 20% to 30% of federal and state prisoners report being under the influence of alcohol or drugs at the time of the violent crime for which they are incarcerated. Toxicology studies show frequent alcohol and drug use among firearm homicide and suicide decedents as well.3,4 Beyond correlation, the causal relationships between alcohol, drugs, and firearm homicide and suicide are complex. The best available evidence suggests that (1) alcohol misuse increases the risks for firearm homicide perpetration and suicide, and (2) involvement in illegal drug sales increases the risks of firearm homicide perpetration and victimization. But consistent with the findings of Hohl et al,1 the evidence does not support a causal relationship between acute alcohol or drug intoxication and increased risk of becoming a victim of firearm homicide.3,5
The pharmacological effects of alcohol intoxication can decrease inhibitions, impair judgment, and lead to impulsive and violent behavior.4,5 The consequences of alcohol misuse can be deadly when there is ready access to a firearm. The strongest support for this claim is research linking alcohol misuse with a heightened risk of perpetration of intimate partner firearm homicide and with firearm suicide.4 Firearm owners are more likely than non–gun-owners to report high-risk alcohol use, underscoring the importance of reducing the access of individuals who misuse alcohol to firearms.4
In contrast, the evidence does not clearly support a pharmacological pathway between any illegal drug use and perpetration of firearm violence. A recent review,3 of which one of us was an author, found no association between individuals’ use of any illegal drug and firearm homicide or suicide in prospective studies that controlled for concurrent alcohol use. Psychophysiological effects vary across different types of drugs, however. Use of cannabis and opiates—the most frequently used recreational drugs in the United States—tends to inhibit rather than increase violent behavior, though opiate withdrawal can increase risk of violence.3 The few studies examining drugs more likely to increase violent behavior, such as methamphetamine and cocaine, are hindered by small sample sizes.3 The weight of the evidence indicates that selling illegal drugs or participating in gangs that sell drugs heightens the risk of firearm homicide.3
Substance use also influences the risk of firearm violence through indirect pathways. Substance misuse can negatively affect educational attainment, employment and income, and facilitate association with delinquent peer groups, all of which increase the risk of firearm homicide.3,4 These socioeconomic and social factors also operate as shared risk factors that independently increase the risk of both substance misuse and firearm homicide along other pathways. For example, association with peers who misuse substances or perpetrate violence increase adolescents’ risk of engaging in the same behaviors.3,4 Similarly, mental illness increases the risk of alcohol and drug misuse as well as increasing the risk of firearm suicide.3,4
What approaches might help to prevent firearm violence related to alcohol and drugs? First, restricting access to firearms among individuals who misuse alcohol or sell illegal drugs could help. Owing to minimum legal age restrictions for possessing handguns outside the home, it is likely that the firearms used in homicides perpetrated by the adolescents in Hohl et al’s study1 were obtained illegally, either from illegal transfers or theft. There is evidence that comprehensive background checks, handgun purchaser licensing, and proper oversight of licensed gun dealers reduce the diversion of guns to criminal users and prevent homicides.6
For adults older than 21 years, federal law does not currently include any alcohol-related firearm restrictions. At present, 37 states have such restrictions, but for many of these laws, there are obstacles to enforcement owing to vague firearm prohibitions for “alcoholics” or “habitual drunkards” without accompanying regulations that operationalize these disqualifiers.4,7 Although federal law includes a firearm prohibition for individuals who are “unlawful users of or addicted to any controlled substance,” this category is also poorly defined and there are challenges to enforcement.3 An ongoing study funded by the National Institute of Health is seeking to determine whether misdemeanor convictions (felony convictions already carry a federal firearm prohibition) for alcohol and drug-related offenses, such as driving under the influence and possession of a controlled substance, are associated with future risk of firearm homicide.8 If a strong positive association is found (the study will not be completed for several years), such convictions could be tied to restrictions on owning or possessing a firearm.
Second, the homicide risks of adolescents are substantially higher in neighborhoods with large numbers of arrests for illegal drug sales, as Hohl et al1 demonstrate. Efforts to address this problem have principally relied on more arrests and long prison sentences for drug trafficking. Available evidence suggests, however, that such measures tend to increase gun violence by prompting intragang violence to prevent “snitching” and violence between drug-selling gangs competing for the market disrupted by arrests.9 The evidence suggests that redirecting law enforcement resources to concentrate on illegal gun possession could lead to fewer firearm homicides.6
Finally, interventions to prevent and treat alcohol use disorders, particularly among the adolescents and young adults at highest risk, could reduce firearm violence. Regulations limiting the exposure of youth to alcohol advertising and zoning laws limiting the density of alcohol outlets have the potential to prevent alcohol initiation and misuse by adolescents.10 Although Hohl et al1 found no association between neighborhood exposure to alcohol advertisements and firearm homicide, their finding may be related to the relatively small sample size; other studies show that advertising exposure increases alcohol initiation and use.10 An example of an effective early intervention approach is Screening, Brief Intervention, Referral and Treatment (SBIRT), which is increasingly reimbursed by government and other health insurers. This intervention, which includes screening, a brief therapy intervention to increase awareness and motivation for behavior change, and referral to treatment when needed, has been shown to increase the identification of substance use disorders and treatment in adolescents and young adults.10 Expanded implementation of SBIRT services, especially in settings frequented by youth, such as schools and primary care clinics, could help to prevent firearm violence.
Corresponding Author: Daniel W. Webster, ScD, MPH, Center for Gun Policy and Research, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, 624 N Broadway, Room 593, Baltimore, MD 21205 (email@example.com).
Published Online: January 3, 2017. doi:10.1001/jamainternmed.2016.8192
Conflict of Interest Disclosures: None reported.
McGinty EE, Webster DW. The Roles of Alcohol and Drugs in Firearm Violence. JAMA Intern Med. Published online January 03, 2017. doi:10.1001/jamainternmed.2016.8192