Deaths from drug overdoses have increased 50 per cent in Northern Virginia recently, with abuse of tranquilizers and barbiturates by older people accounting for the largest proportion of those deaths, says a year-end report on drug abuse by a Northern Virginia planning agency.

Drug abuse, often thought as the province of the young, appears to afflict older segments of the Northern Virginia population more seriously, the report indicates. Alcohol was included as a drug in the report.

The report shows that 65 deaths resulted from drug overdose from July, 1975, through June, 1976, compared to 43 drug-related deaths during the same period the previous year. The deaths represent a 100 per cent increase over drug-related deaths in 1973. There were no reported deaths from drug abuse among blacks.

"It's not kids' abuse of illegal drugs, like marijuana or heroin, that stands out as a major problem," said Joseph Motter, who helped prepare the report by the Northern Virginia Planning District Commission. "It's abuse of licit drugs by older people, obtained under physician's prescription, that accounts for most of the increase in drug overdose deaths."

Northern Virginia residents 45 years old or older accounted for nearly 50 per cent of all drug overdose deaths in that region from July 1975 through June 1976, a 16 per cent increase over the same period the previous year. Most of those deaths resulted from overdoses of barbiturates and tranquilizers. Common barbiturates and tranquilizers include, librium, seco-barbital and phenobarbital. Fifteen of Northern Virginia's 42 deaths from tranquilizer and barbiturate overdose were women 45 years or older, making them the largest single category of drug abuse victims.

By comparison, drug overdose by those 18 and younger accounted for only two per cent of Northern Virginia's drug-related deaths. Only one male under 18 died of drug overdose in the period covered by the report. It is believed the death resulted from use of either chloroform, glue or aerosol.

"The seriousness of drug abuse by older people is just beginning to be brought out," Motter said. "Before, the focus was on the young, because arrests were involved in the use of illegal substances. You don't get arrested for taking a tranquilizer or a drink even though you can die from it."

The planning commission last week endorsed a drug abuse treatment plan that focuses on older segments of Northern Virginia's population as the group in need of drug treatment programs.

Older people abusing legal substances like tranquilizers and alcohol greatly exceed their proportion of the population, Motter added.

Motter explained that deaths from use of opiates accounted for only 12 per cent of all Northern Virginia drug-related deaths from July 1975 through June 1976, compared to 20 per cent in the same period the previous year. Common opiates include heroin, methadone and demerol. However, victims of death were not only the very young. Opiate abuse killed four people between 19 and 25 years old and three people 45 years or older. Another between the ages of 26 and 44 also died from opiate overdose.

Next to barbiturates and tranquilisers, alcohol ranked the second largest killer in the report. Ten people died of alcohol abuse from July, 1975, through June, 1976. Again, Northern Virginia residents 45 or older accounted for most of the alcohol-related deaths. Six persons 45 and older died from alcohol abuse compared to four people younger than 45.

"Young people do not appear to be dying from abusive use of drugs, as are older people," said Allison Martin, a Northern Virginia District Planning Commission specilaist in substance abuse. "Nor do they appear to be coming in large numbers to hospital emergency rooms as a result of drug abuse."

The repport also surveyed several Northern Virginia hospital emergency rooms to obtain a better scope of drug abuse in the area, Motter said. The survey included Alexandria, Arlington, Commonwealth Doctors, Loudoun, Prince William and Potomac and Fairfax hospitals.

The survey substantiated some of the findings in the report on drug abuse deaths in Northern Virginia.

Although slightly more men died from drug abuse in the period July, 1975, through June, 1976, many more women were treated for drug abuse in the six hospital emergency rooms. Sixty-seven per cent of drug cases (not including alcohol) treated in the emergency rooms were women, and most of those cases involved abuse of tranquilizers and barbiturates.

Tranquilizers and barbiturates accounted for 31 per cent of all drug-related emergency room cases in the survey, while illicit drugs accounted for only eight per cent. Illicit drugs include heroin, cocaine, marijuana, hallucinogens and PCP, an animal tranquilizer.

While no blacks were reported to have died from drug abuse in the same period, nearly 14 per cent of emergency room drug cases were blacks. Blacks represent about eight per cent of the Northern Virginia population. Blacks represented 32 per cent of heroin abuse cases in the emergency rooms.

The largest porportion of cases treated involved tranquilizers and barbiturates, 23 per cent involved unknown drugs, 17 per cent involved a variety of drugs, inlcuding ether, aerosol and chloroform, 13 per cent were alcohol cases, eight per cent of the cases involved illegal drugs including hallucinogens, marijuana, cocaine and heroin and seven per cent of the cases involved commercial drugs sold over the counter.