While the battle rages over the escalating cost of some prescription drugs, American consumption of these pharmaceuticals in general is at an all-time high, with no slowing of usage in sight.

That’s what a team of researchers from Boston and New York institutions found when they examined federal prescription drug use data. Their main finding: 59 percent of adult Americans filled at least one prescription drug order in 2011-2012, compared to 51 percent in the 1999-2000 study period.

The percentage of those who filled at least five drug orders rose from 8 percent in 1999-2000 to 15 percent in the later study period. The increased demand was largely made up of mood changers, drugs that address obesity, muscle relaxers and certain proton pump inhibitors.

A higher number of older Americans are now using prescription drugs than in 1999-2000, but prescription drug use hasn’t grown much among those ages 20 to 39, the researchers reported. In the 40-to-64 age category, use was up from 57 percent in 1999-2000 to 65 percent; among those age 65 and older, usage increased from 84 percent to 90 percent. In the youngest category, use increased just 3 percent, to 35 percent. However, there were some anomalies. For instance, the use of muscle relaxants rose among women much more so than among men.

Other highlights:

Racial consumption of prescription drugs: “Although significant increases in the percentage of persons using five or more prescriptions were observed in all racial/ethnic groups, an overall increase in prescription drug use was evident among individuals who were non-Hispanic white (55 percent-66 percent) and non-Hispanic black (43 percent -52 percent), but not Mexican American (30 percent -33 percent). This pattern remained unchanged with age adjustment.”

Drugs of choice: “All of the top 10 most commonly used drugs increased over the study period except atorvastatin.”

No. 1 drug: “The most commonly used individual drug in 2011-2012 was simvastatin (7.9 percent), increasing from 2.0 percent in 1999-2000.”

Blood pressure: “Use of antihypertensive drugs increased over the study period, with a marked increase observed for several antihypertensives, including thiazide diuretics.”

Statins: “Use of antihyperlipidemics increased markedly, driven primarily by an increase in use of statins, for which the greatest increase was observed prior to 2005-2006.”

Depression: “The increase in use of antidepressant drugs may, in part, reflect shifting attitudes regarding depression.Use of selective serotonin reuptake inhibitors and selection serotonin and norepinephrine uptake inhibitors markedly increased; notably, use of SSNRIs increased between 1999-2000 and 2005-2006, remaining stable thereafter.”