A study at the University of Illinois at Chicago by Adam Negrusz found that of all of the sexual assaults that were "drug facilitated," the classic date-rape drugs were used in only a small percentage.
"An estimated 100,000 sexual assaults are committed in the United States each year, and the FBI says that number could be three times higher if all cases were reported," said Adam Negrusz, associate professor of forensic sciences in the UIC College of Pharmacy.
Negrusz was lead author of the study titled "Estimate of the Incidence of Drug-Facilitated Sexual Assault in the U.S." He said individuals who use drugs, with or without alcohol, are at a significantly higher risk for sexual assault.
"In some cases the substances are taken voluntarily by the victims, impairing their ability to make decisions," Negrusz said. "In other cases the substances are given to the victims without their knowledge, which may decrease their ability to identify a dangerous situation or to resist the perpetrator."
"In about 80 percent of the cases the victim knows the assailant," he said in a news release, "while only 20 percent of sexual assaults are opportunistic."
Negrusz collected data from 144 subjects who sought help in clinics located in Texas, California, Minnesota and Washington state. The subjects were from all ethnic backgrounds and ranged in age from 18 to 56. The mean age of the victims was 26.6. Subjects who volunteered for the study provided two urine samples and a hair specimen and completed a questionnaire that asked them to describe the assault and any drugs they were using.
"The urine and hair specimens were analyzed for about 45 drugs that have either been detected in sexual assault victims or whose pharmacology could be exploited for drug-facilitated sexual assaults," Negrusz said. Negrusz identified two types of drug-facilitated sexual assault: presumed surreptitious drugging, or willful drug use by the subject.
Majority Had Drugs in Their SystemThe study results included:
- 61.8 percent of the subjects were found to have at least one of the 45 analyzed drugs in their system.
- 4.9 percent tested positive for classic date-rape drugs.
- 4.2 percent had been drugged without their knowledge.
- Of those who voluntarily took drugs, 35.4 percent were impaired at the time of the sexual assault.
Toxicological Analysis Needed"This study demonstrated the need for toxicological analysis in sexual assault cases," Negrusz said, due to the high percentage of subjects who tested positive for drugs. "It also demonstrated that sexual assault complainants severely underreport their illegal drug usage. This could be corrected if the administering nursing staff was better educated on taking a truthful drug history."
"The study also confirmed that drug-facilitated sexual assault is more often due to the subject's own drug use," he said, "Rather than surreptitious drugging by the perpetrator."