Seventy-five percent of men and 55% of women have used drugs and/or alcohol prior to an assault.

In 2009, an estimated 22.5 million persons (8.9 percent of the population aged 12 or older) were classified with substance dependence or abuse in the past year based on criteria specified in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). Of these, 3.2 million were classified with dependence on or abuse of both alcohol and illicit drugs, 3.9 million were dependent on or abused illicit drugs but not alcohol, and 15.4 million were dependent on or abused alcohol but not illicit drugs.

Among persons aged 12 or older in 2007-2008 who used pain relievers nonmedically in the past 12 months, 55.9 percent got the drug they most recently used from a friend or relative for free. Another 18.0 percent reported they got the drug from one doctor. Only 4.3 percent got pain relievers from a drug dealer or other stranger, and 0.4 percent bought them on the Internet. Among those who reported getting the pain reliever from a friend or relative for free, 81.7 percent reported in a follow-up question that the friend or relative had obtained the drugs from just one doctor.

Although the rate of past month illicit drug use was higher among unemployed persons compared with those from other employment groups, most drug users in 2009 were employed. Of the estimated 19.3 million current illicit drug users aged 18 or older in 2009, 12.9 million (66.6 percent) were employed either full or part time. The number of unemployed illicit drug users increased from 1.3 million in 2007 to 1.8 million in 2008 and 2.5 million in 2009, primarily because of an overall increase in the number of unemployed persons between 2007 and 2009. Increases also were seen in the numbers of past month illicit drug users among adults who were employed part time (from 3.1 to 3.6 million) and those in the "other" employment category (retired persons, disabled persons, homemakers, students, and other persons not in the labor force) (from 3.1 to 4.0 million). NSDUH estimates the numbers of persons who were employed full time were 122.2 million in 2008 and 114.8 million in 2009; the estimated numbers of unemployed persons were 9.0 million in 2008 and 14.7 million in 2009. The rate of current illicit drug use among unemployed adults was 19.6 in 2008 and 17.0 percent in 2009; although this difference is not statistically significant, the rate in 2009 may reflect the inclusion of persons who had been employed in 2008 but were unemployed at the time they were interviewed in 2009.