The number of active-duty personnel who died by suicide in 2015 declined slightly from 2014, but the reserve component, including the National Guard, saw a 23 percent increase, according to Pentagon data released Friday.

The Defense Department's fourth-quarter suicide report for 2015 said 266 active-duty service members committed suicide in 2015, down from 273 in 2014.

The number of r​Reserve component members who died by suicide — including those from the Army, Navy, Air Force and Marine Corps reserves as well as Air and Army National Guard troops — rose to 209 from a four-year low of 170 in 2014.

Figures for the active component have remained relatively steady since peaking at 321 in 2012, but they are nearly double the number before the Iraq and Afghanistan wars.

The Defense Department has stepped up its suicide prevention and awareness campaigns in the past five years to reverse the climb in suicides, establishing the DoD Suicide Prevention Office in 2011 to spearhead suicide awareness and prevention efforts within the department and individual services.

The DSPO has an annual budget of $24 million. The Pentagon also is the largest single supporter of suicide prevention research, funding 61 studies in recent years at a cost of more than $100 million, according to a Rand Corp. report.

Suicide prevention training is mandatory in all five military services, including the Coast Guard, whose suicide statistics are not included in the Defense Department tally.

According to the report, 120 soldiers, 39 Marines, 43 sailors and 64 airmen died by suicide in 2015. The number of Air Force deaths marks the highest for the service in the past decade.

Among the reserves and National Guard, 88 Army, Navy, Air Force and Marine reservists died by suicide in 2015, while 100 Army National Guard members and 21 Air National Guardsmen killed themselves.

Suicide prevention experts say the high number of reserve and National Guard deaths may be linked to fewer resources for these troops, who may not have the same access to support services and mental health care as active personnel.

The quarterly DoD reports are issued to "allow leaders at all levels to have near-concurrent information that facilitates decision-making" related to prevention. The 2015 report drew no conclusions about the figures other than noting that a decrease in the fourth quarter, and increase in the reserve component deaths, may warrant additional comparative analysis to see if the changes are statistically significant.

In-depth analyses of military suicides and attempts in a calendar year are issued annually by the Defense Department. The 2014 Department of Defense Suicide Event Report, which examined the rate of suicide in the services, demographic trends including age, gender, rank and marital status, as well as known or suspected causes of suicide behavior, was released in January 2016.

Patricia Kime covers military and veterans health care and medicine for Military Times. She can be reached at pkime@militarytimes.com.