SAN DIEGO COUNTY - While the number of adults that test positive for drugs when arrested dropped slightly in 2006 compared with the year before, narcotics use continues to show up in more than 70 percent of arrestees, according to a report released Tuesday by the San Diego Association of Governments.

The report shows that 75 percent of women and 66 percent of men tested positive for at least one drug, including marijuana, cocaine, PCP, heroin or methamphetamine, representing a 1 percent drop overall since 2005. Among those, 89 percent of arrestees test positive for two drugs, 10 percent for three drugs and one percent for four, with the most common combination being marijuana and methamphetamine.

The percentages are based on drug tests administered over four separate months in 2006 to a total of 736 participants within 48 hours of their arrest and booking into Vista, Central or Las Colinas jails.

One key finding is that a spike in meth use reported in 2005 fell back to earlier levels in 2006, indicating that the increase was not a trend, said Cynthia Burke, director of the association's Criminal Justice Research Division. Meth use fell 8 percent for men, to 36 percent, and 4 percent for women, to 47 percent. A similar drop was seen among juveniles in the same time period.

"Whatever caused the increase, we're back down to the levels from 2004, which is a positive," Burke said.

Still, meth continues to be the drug of choice for men and women, the report says.

Women have tested positive for drugs more often than men every year since 2000, and are most likely to use meth, cocaine and heroin, while men tend to report recent alcohol use and test positive for marijuana, the report says. This year's report shows the greatest gap yet in drug use between men and women.

In some cases, drug use among women may stem from them having a greater history of abuse, running away and getting into trouble with the wrong men, Burke said.

"They're more likely to be involved (in crime) because of a partner," she said. "Women stereotypically tend to hurt themselves more than other people. … It's an escape, depression is more common, sometimes they self-medicate."

Drugs can be "sort of escapism" for abused women, said Kathy Valenzuela, executive director of the North County Serenity house, an Escondido-based treatment organization.

"An overwhelming percentage, 80 percent, have experienced sexual trauma - incest, molestation, rape," Valenzuela said, adding that those traumatic events tend to turn women toward drug use.

Women may also turn to drugs such as meth to lose weight, Burke said.

The report also showed a large number of older adults using drugs, with meth use was highest among 25- to 39-year-olds, while cocaine and heroin was used most by those 40 and older.

Because many older users developed drug habits at a young age, "it's scary to think what will happen to teens that start using so early," Burke said.

Drug use is also common among those with mental health issues, and 21 percent of the arrestees reported being previously diagnosed with a mental or psychiatric disorder, including 17 percent that had been hospitalized overnight. Of that total, 51 percent were currently prescribed medication and of those, 35 percent were not taking them. Sixty-four percent lacked health insurance at the time they were questioned.

Those with mental health issues are more likely to test positive for drugs, have parents that use drugs, have previous arrests and receive drug treatment. The issue, the report states, supports "the view that addressing the needs of … (those with mental and drug treatment needs) is a key issue for the criminal justice system."

- Contact staff writer Sarah Wilkins at (760) 740-3524 or swilkins@nctimes.com.