Article, Forensic Medicine

Perpetrators of intimate partner violence use significantly more methamphetamine, cocaine, and alcohol than victims: a report by victims

Perpetrators of intimate partner violence use

significantly more methamphetamine, cocaine, and alcohol than victims: a report by victims

Amy A. Ernst MDa,?, Steven J. Weiss MDa, Shannon Enright-Smith LMSWb,

Elizabeth Hilton MDa, Emily C. Byrdc

aDepartment of Emergency Medicine, MSC10 5560 1 University of New Mexico, Albuquerque, NM 95817, USA

bResources Inc., Albuquerque, NM, USA

cUniversity of Texas, Austin, TX 78705, USA

Received 21 August 2007; revised 14 September 2007; accepted 15 September 2007


Objectives: Our objectives were (1) to determine demographic characteristics of intimate partner violence victims and perpetrators, as reported by victims in a Victim Assistance Unit where police are called to the scene for IPV, and (2) to compare the relative risk of methamphetamine, cocaine, and alcohol use in perpetrators vs victims of IPV, as reported by victims.

Methods: Data from a Victim Assistance Unit intake statistics for the months of January to November 2006 were accessed. For this system in a city of approximately 500 000 population, with a large Hispanic population, police call for an onsite advocate intervention (trained social worker) at their own discretion for the victim and for children involved. Data were collected from the homes visited by police for IPV calls based on victim report on victims, perpetrators, and children in the home and their involvement in IPV. Reports of drug use were self-reported by the victim only. Comparisons were made using ?2 tests, Relative risks (RRs), and 95% confidence intervals (CIs). P b .05 was considered statistically significant.

Results: Police and advocates visited 1712 homes for IPV calls; males were victims in 141 (8.2%) cases. Nine hundred ninety-seven (58.2%) victims were Hispanic. By victim report, perpetrators were significantly more likely to have witnessed IPV as a child than victims did (48.8% vs 34.3%; RR, 1.4; 95% CI, 1.3-1.6). Of the 2266 children in these homes, 1800 (79.2%) witnessed IPV and 716 (31.6%) were victims themselves. By victim report, the perpetrators were significantly more likely to use methamphetamine (8.9% vs 0.8%; RR, 10.9; 95% CI, 6.4-18.8 ), cocaine (11.8% vs 0.7%; RR, 16.8),

and alcohol (53.3% vs 12.9%; RR, 4.1; 95% CI, 3.6-4.7) than victims.

Conclusion: By victim report, perpetrators were more likely to have witnessed IPV as children. By victim report, perpetrators were also more likely to use methamphetamine, cocaine, and alcohol and other drugs. Knowing this correlation may be important to the emergency department physician as screening for drug use, especially methamphetamine, as well as IPV may be useful to identify IPV- related injuries and provide proper referrals for IPV and drug use treatment.

(C) 2008

* Corresponding author. Tel.: +1 505 272 5062; fax: +1 505 272 6503.

E-mail address: [email protected] (A.A. Ernst).

0735-6757/$ – see front matter (C) 2008 doi:10.1016/j.ajem.2007.09.015


Alcohol and drug use have been reported to be high in both victims and perpetrators of Intimate partner violence [1-4]. How much is used by each group and specific drugs involved are unknown. Recently, in the United States, there has been a large resurgence of methamphetamine use [5-7]. The effects on IPV have been reported but only rarely and anecdotally [2,5-7]. Because of the stimulant nature of methamphetamine, it has been associated with increased violence including sexual violence both in relationships as well as with others, known or unknown to the person, using metham- phetamine [8].

Cohen et al [6] report that past and current inter- personal violence is a characteristic of the lifestyles of most entering treatment of methAmphetamine dependence. This includes perpetration of violence with partners and victimization. Patients who are victims of IPV are often identified in the emergency department (ED). Because of the correlation of IPV with alcohol and methamphetamine use, the ED physician should be aware of this and should question patients about substance use if they are victims or suspected perpetrators of IPV.

In a Victim Assistance Unit in a city of approximately 500 000 population, counselors have recently begun to gather data about the use of specific drugs in IPV victims as well as victims’ reports of perpetrator’s drug use.

The purpose of this study was to determine demo- graphics of IPV victims, perpetrators, and children in homes of cases where police are called to the scene for IPV. In addition, we sought to compare relative risks of methamphetamine, cocaine, and alcohol use in perpetra- tors vs victims of IPV based on IPV victims’ reports. Our hypothesis was that drug use, especially metham- phetamine, and alcohol use was higher in perpetrators than in victims.


Study setting and population

Data collected by the local Victim’s Assistance Unit from January 2006 to November 2006 was accessed in a city with a population of 500 000. The study population comprised victims of IPV where police are called to the scene of an IPV incident. In this system, police initiate calls to the ED immediately where appropriate and to the Victim Assistance Unit at their discretion for onsite advocates for adult victims and children who witness IPV. Starting in January 2006, victim report of specific drug and alcohol use by the victim and perpetrator were included in data collection. The population of the metropolitan area is approximately 48% Hispanic.

Study protocol

The study was a retrospective cohort study of perpetrators vs victims of IPV. At the time of the intervention, data are collected on victims, perpetrators, and children in the homes

–all from the victim and victim’s children. Information about perpetrators is gathered at the time of intake and throughout treatment as long as the victim and children continue with the system. After ED visits for acute injuries, services provided included crisis intervention, information, referrals, safety planning as well as transportation, medical intervention, child safety plans and implementation, child advocacy (begun immediately, a unique aspect of this program), IPV education, and placement in shelters for safety, as well as help with legal matters including orders of protection. This study was reviewed and approved by the institutional review board as exempt before data evaluation because no personal identifiers were used.


Demographics collected from victims included informa- tion about children’s victimization in the homes, type of IPV, sex of the victims, ethnicity, ages, relationship status, children involved, demographics, victim and perpetrator use of alcohol, drugs, previous encounters with IPVor sexual abuse, and services provided.

At the time of first contact, the victim/child advocate or therapist recorded pertinent data, including demographic information. Every child and victim in the household was interviewed. This process started at the time of the call. Evaluation for safety and referral to the ED if needed was performed. Parental consent for continued intervention and permission for the child’s (children’s) enrollment into the project was obtained. The advocates, case manager, and therapists of the Victim Assistance Unit gathered to evaluate the victim’s and child’s (children’s) response information and compared it for progression at appropriate periods and in relation to the participation by component in the program. Staff provided summary reports at each intervention to track progress with aspects of the program, economic changes, and attrition from the program.

The information from the study was abstracted by social workers at the Victim Assistance Unit, the local IPV treatment group. data forms were filled out by each patient at sessions that occur for a 1-year treatment period. Missing information was noted, and percentages of missing data were calculated.

Measurements and key outcome measures

Outcome measures were all based on self-reports of victims concerning both themselves and perpetrators. These included descriptive data and comparisons as well as comparison of perpetrators to victims for alcohol and drug

use, especially methamphetamine, as well as for previous abuse/witnessing of abuse as children.

Statistical analysis

Descriptive statistics were calculated using ?2 tests and 95% confidence intervals (CIs) to compare victims and perpetrators. Relative risks (RRs) with CIs were used to compare perpetrators vs victims. Relative risks with CIs excluding 1 were significant at the P b .05 level.

We performed a sample size calculation. For this calculation, we assumed a 40% prevalence of drug use among perpetrators. We calculated that a sample of more than 1500 would allow us to have a power of 80% to detect a 5% difference between perpetrator and victim drug use with an ? = .05.


Descriptive statistics were available in all 1712 cases (see Table 1). The ethnicity of the couple was unknown in 59 (3%). Data on alcohol use were unknown in 10 (0.6%) of victims and 13 (0.8%) of perpetrators; information on sex was missing in 8 (0.5%) of victims. Drug use history was missing in 10 (0.6%) of victims and 15 (0.9%) of offenders. The information about witnessing IPV as children was available in all cases (100%).

Police and advocates visited 1712 homes for IPV calls. Among adult victims, 1563 (91%) were female, and 141 (8%), male. Victims’ ethnicities were mostly Hispanic (58%) with 28% white and 5% American Indian. Others are shown in Table 1. The local population is approximately 48% Hispanic, 40% white, 10% American Indian, and 2% other ethnic groups. There were 2266 children in these homes:

Table 1 Demographic data

n (%)

Sex of victims (N = 1712) Male


Ethnicity of victims White


Native American African American Asian


Witnessed IPV as a child Victims

Perpetrators Abused as a child Victims Perpetrators

141 (8)

1563 (91)

475 (28)

997 (58)

93 (5)

65 (4)

12 (1)

59 (3)

587 (34)

836 (49)

468 (27)

760 (44)

Victim, n (%)

Perpetrator, n (%)

RR (95% CI)

Witnessed IPV





1.4 (1.3-1.6)

as child

Abused as a child





1.6 (1.5-1.8)

Alcohol use





4.1 (3.6-4.7)

Drug use





9 (7.3-11.5)






10.9 (6.4-18.8)






26 (14.5-46)












15 (9.8-23.9)






11.8 (6.2-22)

Prescription drugs





3.2 (2-5.3)

IPV, intimate partner violence; NA, not applicable.

1153 male, 1073 female, and 40 unknown sex; 1800 (79%) witnessed IPV, and 716 (32%) were victims of child abuse.

According to victim report, perpetrators were more likely to have witnessed IPV as a child than victims did (49% vs 34%; RR, 1.4; 95% CI, 1.3-1.6). According to victims, perpetrators were also more likely to have been abused as a child than victims were (44% vs 27%; RR, 1.6; 95% CI, 1.5- 1.8). See Tables 1 and 2.

Table 2 Associated factors in adult victims and perpetrators (relative risks of methamphetamine, cocaine, and alcohol use)

Table 2 shows victim report of victim vs perpetrator use of alcohol and specific drugs. Forty-two percent of perpetrators used drugs. Overall, victims reported that perpetrators were 4 times more likely to use alcohol and 9 times more likely to use drugs than victims. Victims reported that perpetrators were 11 times more likely to use methamphetamine, 26 times more likely to use cocaine, and 15 times more likely to use marijuana than victims.


Methamphetamine is a stimulant drug with high depen- dence liability [9,10]. Its medical use in nasal decongestants started in the 1930s; however, nonmedical uses are common- place. It can be readily manufactured from cold remedies and can be smoked, snorted, injected, or swallowed [11]. The desired effects of the drugs are often overshadowed by undesirable effects, including Psychotic symptoms of paranoia, hallucinations, delusions of persecution, anxiety, and agitation that can lead to aggressive behavior [11-13]. United States law enforcement agencies report association of methamphetamine use and high levels of criminal violence, far exceeding that of any other drug use. Thrill-related violent crimes are reported just from its use [14,15].

Although methamphetamine users perpetrate IPV, they are often victims of violence as well. In one of the few studies of methamphetamine use in an ED population, Richards et al [16] reported a strong association of

methamphetamine use and violence victimization in an ED population of methamphetamine users. Alcohol use was also strongly correlated. Association with IPV was not deter- mined in this setting.

In a study of IPV across medical specialties, the highest incidence was reported from addiction recovery units and EDs [17]. The relation of drugs and IPV has been previously established. Intimate partner violence and alcohol use are associated in previous studies as well [4].

Given the link between illicit drug use such as methamphetamine and IPV, identifying persons at increased risk for victimization could be facilitated in the ED setting. Intimate partner violence victims as well as perpetrators may present to the ED setting, often as results of intentional injury or as sequelae of illicit drug use [16]. Screening for IPV and methamphetamine use in these populations in the ED may be of value to assist victims and refer both victims and Drug users to appropriate treatment sites. This may be a way to help end the cycle of IPV [3,4,6,16]. Often, it is challenging for ED physicians to keep current with services available in the community such as alcohol/drug rehabilitation facilities, IPV victim support groups, IPV perpetrator treatment groups, or other treatment centers. A simple referral from the ED to a program such as the Victim’s Assistance Unit described above could help facilitate such services.

Methamphetamine use heightens the risk for negative health, psychological, and social outcomes. Virtually, all respondents in a drug treatment program reporting metham- phetamine use had negative consequences of its use [8]. Problems with spouses and relationships were most apparent. Fifty percent reported negative consequences on relation- ships. Often, this included violence. Thirty-seven percent of males and 30% of females using methamphetamine reported committing violent acts; 46% of these reported no prior acts before use of methamphetamine. In a study involving teens, alcohol and methamphetamine use were significantly associated with partner violence [18]. A possible explanation for this association includes the substances’ disorganizing effect on Cognitive functions. In a study by Cartier et al [19] in which demographic and other abused substances were controlled, methamphetamine use was predictive of violence and recidivism.

Whereas methamphetamine users are often victims of violence, we found in our study that, according to IPV victims, perpetrators were more likely to be users of methamphetamine and alcohol than victims. This included other drugs as well. In addition to methamphetamine, cocaine, marijuana, crack, and prescription drugs were more likely to be used by perpetrators than victims.

Our study illustrates that there were substantial numbers of children who have witnessed the IPV in homes where police are called for IPV. These children were victims 32% of the time. Research has shown that children in situations where they witness and/or are victims of IPV are more likely to have aggressive, delinquent behavior, as well as anxiety and depression compared to a normative group [20]. They are

likely to have academic as well as school health problems [20] indicating an adverse effect on overall lives and behaviors. They are also likely to abuse alcohol and drugs [17]. This research indicates the importance of intervention at an early stage because even children who witness IPV are victims and negatively affected by the experience. Studies show that these children are likely to be more violent themselves, to use drugs, and to continue the cycle of IPV [20].

We believe that witnessing IPV and watching a parent who uses alcohol and drugs result in learning of negative behaviors in some children leading to the perpetuation of violence in IPV. Intervention at an early stage is needed. According to victims, perpetrators of IPV in our study were more likely to have witnessed IPV as children than victims, consistent with previous studies [21,22]. Emergency depart- ment identification and referral for intervention for the entire family may be a good way to help stop the cycle of IPV.


The data are from 1 urban community site with a large Hispanic population. This could affect external validity of this study.

By using survey-based data as reported only by victims of IPV, there may have been overreporting of perpetrator exposures (drug use, sexual assault, witnessing IPV as a child) because of possible legal implications surrounding the individual case. Conversely, there may have been under- reporting of self drug or alcohol use because of fears of legal ramifications including child custody and having children removed from their homes or placed in foster care.

Data were collected by self-report of the victim so that the truthfulness of reports of alcohol or drug use cannot be verified. Because the police determined when to call for a social worker involvement, this too could lead to bias in accuracy of reporting.

It is unknown if there were errors in the data collection, although none are known.

Data about alcohol, drug use, ethnicity, sex, and ages were missing in some of the patients. The child witnessing information was available in all cases.


By victim report, perpetrators used significantly more illicit drugs and alcohol than victims. A history of childhood IPV was significant in the history of perpetrators and victims, more so in perpetrators than in victims by victim report. In the ED, identifying victims and perpetrators of IPV may be important to help end the cycle of violence in IPV. Intimate partner violence victims as well as perpetrators may present to the ED setting with injuries or for drug use-related problems. Screening for IPVand methamphetamine use may be of value

to refer victims to support groups and perpetrators to treatment groups.


  1. Cronholm P. Intimate partner violence and men’s health. Prim Care 2006;33:199-209.
  2. Dube SR, Anda RF, Felitti VJ, et al. Exposure to abuse, neglect, and household dysfunction among adults who witnessed IPV as children: implications for health and social services. Violence Vict 2002;17: 3-17.
  3. Cunradi CB, Caetano R, Schafer J. Alcohol-related problems, drug use and male intimate partner violence severity among US couples. Alcohol Clin Exp Res 2002;26:493-500.
  4. Lipsky S, Caetano R, Field C, Larkin G. Psychosocial and substance- use risk factors for intimate partner violence. Drug Alcohol Depend 2005;78:39-47.
  5. Assael LA. Methamphetamine: an epidemic of oral health neglect, loss of access to care, abuse, and violence. J Oral Maxillofac Surg 2005;63: 1253-4.
  6. Cohen JB, Dickow A, Horner K, et al. Abuse and violence history of men and women in treatment for methamphetamine dependence. Am J Addict 2003;12:377-85.
  7. Halpern LR, Susarla SM, Dodson TB. injury location and screening questionnaires for intimate partner violence. J Oral Maxillofac Surg 2005;63:1255-61.
  8. Sommers I, Baskin D, Baskin-Sommers A. Methamphetamine use among young adults: health and social consequences. Addict Behav 2006;31:1469-76.
  9. Wolkoff DA. Methamphetamine abuse: an overview for health care professionals. Hawaii Med J 1997;56:34-6.
  10. Murray JB. Psychological aspects of amphetamine-methamphetamine abuse. J Psychol 1998;132:227-37.
  11. Topp L, Degenhardt L, Kaye S, Darke S. The emergence of potent forms of methamphetamine in Sydney, Australia: a case study of the IDRS as a strategic early warning system. Drug Alcohol Rev 2002;21: 341-8.
  12. Degenhardt L, Topp L. ‘Crystal meth’ use among polydrug users in Sydney’s dance party subculture: characteristics, use patterns and associated harms. Int J Drug Policy 2003;14:17-24.
  13. Buffenstein A, Heaster J, Ko P. Chronic psychotic illness from methamphetamine. Am J Psychiatry 1999;156:662.
  14. Klee H, Morris J. Crime and drug misuse: economic and psychological aspects of the criminal activities of heroin and amphetamine injectors. Addict Res 1994(I):377-86.
  15. Domier CP, Simon SL, Rawson RA, et al. A comparison of injecting and noninjecting methamphetamine users. J Psychoactive Drugs 2000;32:229-32.
  16. Richards JR, Bretz SW, Johnson EB, et al. Methamphetamine abuse and emergency department utilization. West J Med 1999;170:198-202.
  17. McCloskey LA, Lichter E, Ganz ML, et al. Intimate partner violence and patient screening across medical specialties. Acad Emerg Med 2005;12:712-22.
  18. Baskin-Sommers A, Sommers I. The co-occurrence of substance use and high-risk behaviors. J Adolesc Health 2006;38:609-11.
  19. Cartier J, Farabee D, Prendergast ML. Methamphetamine use, self- reported violent crime, and recidivism among offenders in California who abuse substances. J Intepers Violence 2006;21:435-45.
  20. Kernic MA, Wolf ME, Holt VL, et al. Behavioral problems among children whose mothers are abused by an intimate partner. Child Abuse Negl 2003;27:1231-46.
  21. Ernst AA, Weiss SJ, Enright-Smith S. child witnesses and victims in homes with adult intimate partner violence. Acad Emerg Med 2006;13:696-9.
  22. Ernst AA, Weiss SJ, Del Castillo C, et al. Witnessing intimate partner violence as a child does not increase the likelihood of becoming an adult intimate partner violence victim. Acad Emerg Med 2007;14: 411-8.