In 2015, 163 women and girls killed themselves. That compares to 140 the year before (an increase in the suicide rate for females from 4.0 to 4.7 per 100,000). The biggest increase was among women ages 45 to 54.

Suicide statistics released at the state level and nationally by the Centers for Disease Control routinely lag two to three years behind, at least partly because of the length of time it can take to confirm whether certain deaths were intentional or unintentional.

There were 631 suicides in Massachusetts in 2015, compared with 608 in 2014, according to data from the state's Department of Public Health. That represents an increase in the suicide rate from 9.0 (per 100,000) to 9.3 (per 100,000).

The state's suicide rate continued a decade-long trend and increased 3 percent in 2015, the most recent year for which data are available. The suicide rate for women saw an uptick as compared with 2014 , while the rate among men stayed the same.

"We certainly believe that if we can get people into treatment we can avert a suicide."

Notably, the suicide rate dropped in 2015 for men aged 45 and older. That is the same year the state and its network of regional suicide prevention coalitions and advocates launched a men's depression and suicide awareness campaign centered on a new website called MassMen.org.

Much of the focus of suicide prevention efforts nationwide in recent years has been on middle-aged men -- the group that was seeing the most significant spike in suicides. Advocates and clinicians pointed to economic woes and isolation as possible contributing factors. The rate of suicide among men has always been much higher than among women.

‎Annemarie Matulis, executive director of the Bristol County Regional Coalition for Suicide Prevention, said she's seen an increase in the average age of women dying by suicide over the last five years. The average age is now 46, up from 36. Unlike with men, Matulis said, it's difficult to pinpoint what's driving the trend.

"I'm kind of stepping back and saying we need to look at this more. Why are women dying?" Matulis said. "It's tough — what population do you focus on that you won't miss something else?"

"Unfortunately these numbers do emphasize the fact that suicide rates do continue to increase," said Dr. Douglas Jacobs, founder and medical director of Wellesley-based Screening for Mental Health.

Though he's encouraged by signs that the suicide rate among middle-aged men may be at least leveling off, Jacobs sees another trend in the statistics that concerns him: While 55 percent of the people who died by suicide in Massachusetts in 2015 were known to be in the midst of some sort of mental health problem (and research suggests 90 percent or more of people who die by suicide have mental illness), only 39 percent were receiving some sort of treatment for mental illness or substance abuse.

"We certainly believe that if we can get people into treatment we can avert a suicide. Because suicides, unfortunately, can and do happen while people are in treatment, that doesn't [undercut] the value of treatment," Jacobs said, pointing out that the data from the state don't reveal the type or frequency of treatment or counseling people were receiving.

Resources: You can reach the National Suicide Prevention Lifeline at 1-800-273-TALK (8255) and the Samaritans Statewide Hotline at 1-877-870-HOPE (4673).