The Ellen O’Brien Gaiser Addiction Center’s new treatment facility for women, which opened last week, is probably the most important piece of new construction Butler County has seen in the past 12 months.

Linda Franiewski, the center’s director, said last year that the organization saw a growing need for treatment services among women and needed to expand its treatment center on Old Plank Road. More than a year later, the 4,590-square-foot addition — entirely devoted to addiction treatment services for women — is up and running.

The completion of this project, which Franiewski called the center’s response to a “considerable” increase in the number of women seeking treatment services, represents a huge step forward for women’s health in Butler County.

Women addicted to opioids face a host of fears, dangers and challenges that male addicts simply aren’t subjected to — from the danger of physical or sexual assault while they’re using to treatment barriers if they become pregnant.

And as the nation’s struggle with opioid addiction and overdose deaths has continued, it quickly became clear that treatment services specifically for women were woefully inadequate. Pregnant women in particular are shamefully underserved.

Fewer than a quarter of substance abuse treatment centers across the country offer programs that cater to pregnant or postpartum women, according to the Substance Abuse and Mental Health Administration. And many treatment centers are either wary of providing medication-assisted treatment to pregnant women or refuse them outright.

Meanwhile, the addiction crisis continues to grow among women. A University of Minnesota study published earlier this year found that 2.3 percent of women between the ages of 18 and 44 and 0.8 percent of pregnant women had taken opioids for nonmedical reasons in the past 30 days. That amounts to about 1.4 million women of childbearing age and 50,000 pregnant women abusing opioids.

As Katy Kozhimannil, a co-author of the study, said in March:

“This has profound public health implications.”

Further complicating the issue is the prospect that what we think we know about health and disease (including addiction) may be tainted by gender-based inequities in scientific research. Women are underrepresented in scientific studies that deal with everything from cardiovascular disease to HIV and other conditions, according to the Society for the Study of Addiction. Unsurprisingly, when we do pay attention to this issue, the results can be enlightening. A 2014 study of the daily lives of recovering heroin users found strong evidence that a person’s gender helps shape their journey both into and out of drug abuse.

In other words: gender isn’t the only factor when it comes to designing successful addiction treatment programs, but it is an important factor — and one we have largely ignored at our peril.

That’s why the Gaiser Center’s expansion is such an important step forward for addiction treatment services in Butler County. Not only does it increase the available treatment options for women struggling with substance abuse, it signals a sea-change in the way treatment organizations think about treatment programs and services.