Alan Majchrowicz via Getty Images A gun doesn't need to be fired to play a leading role in an abusive relationship.

Nicole Beverly, a clinical social worker living in Ypsilanti, Michigan, hadn’t given her husband’s gun much thought until the night he pressed it against her head.

It was 2009. Before that, her husband, a former police officer, had never threatened her with his firearm. It sat in a box in their bedroom closet, almost forgotten. Over the years, she said, he had abused her in other ways: Calling her names, shoving her to the ground, throwing objects in her direction. But the gun never made an appearance.

Once it did, everything changed. From then on Beverly, then 36, couldn’t stop thinking about the weapon, she said. She was acutely aware of its exact location in the house at any given time, in terror of when it might be brandished next.

But he didn’t have to take it out again. He only needed to mention it and Beverly would shrink. He frequently threatened to kill her, she said, telling her he knew exactly where to shoot to paralyze her. He told her he would disfigure her face, she said, and that she would never see it coming.

It took five months after the incident for her to gather the courage to leave. And when she did she took the gun.

“I didn’t feel safe leaving the relationship knowing he had it in his possession because he was threatening me with it on a regular basis,” Beverly told The Huffington Post by phone on Wednesday. “Once it was introduced into the equation, it became a tool of intimidation and fear.”

While the gun in her home was never used to injure her in a way that was physically observable, living in constant fear took a steep toll on her mental health and made it far more difficult for her to leave.

Beverly represents countless women who’ve found themselves in similar positions where a firearm becomes a symbolic weapon of mass destruction in their relationships ― even when the trigger is never pulled.

A new study published in the Journal of Women’s Health by Susan B. Sorenson, a researcher at the University of Pennsylvania, is now shedding light on the psychological impact of gun use in abusive relationships.

Working with the police department in Philadelphia, Sorenson examined 35,000 domestic violence incidents that occurred in the city in 2013, the most recent year in which complete data was available. She studied the role of guns in domestic incidents, and looked at what effect they had on victims.

In the incidents during which an external physical weapon was used, one-third involved guns. When a gun was present, it was rarely fired, Sorenson said.

More commonly, 69 percent of the time, it was used to threaten or coerce the intimate partner, much like Beverly described her husband doing to her. Guns were only fired 10 percent of the time.

“I was interested in this topic because so much is focused on women’s deaths, I thought it was important to look at guns in women’s lives,” she said.

Though victims who had a gun used against them were less likely to have visible injuries compared to victims who reported the use of other weapons, like knives or bats, she said, they were far more likely to experience high levels of fear.

That chronic fear can be extremely detrimental to a person’s physical and mental health, said Julian Ford, a professor of psychiatry at the University of Connecticut School of Medicine and Law.

If a person does not feel safe inside their own home and believes they could be injured or killed at any time, they will go into a survival state, he said, describing it as being in a constant “fight or flight” mode ― but having nowhere to go.

“It is enormously hard on the person psychologically and on the body physically,” he said.

Experiencing trauma of this kind can make a person more susceptible to medical illnesses, Ford said, as well as a wide range of emotional and behavioral difficulties including depression, anxiety and sleep problems.

“The full range of life is affected because the person cannot really let down their guard,” he said.

For Beverly, it was debilitating back pain, recurrent shingles and depression. She said she learned to shut off her emotions to stay safe. If she cried or showed fear, her husband would become enraged, she said.

A person living in constant fear is more likely to be controlled by it, and subsequently their abusive partner. That overwhelming fear could reduce a victim’s willingness to leave or end the relationship, Sorenson said, thus promoting chronic abuse.

“You don’t necessarily need to hit a woman to get her to do what you want,” Sorenson said.

That’s the concept of “coercive control,” a pattern of ongoing behavior used to dominate a partner, she added. It can include psychological, verbal abuse and stalking, and aims to isolate the victim. Firearms can play a big role in helping an abuser to maintain control over his partner.

Injuries and homicides are just the tip of the iceberg. Shannon Watts, founder of Moms Demand Action

For Beverly, the mere presence of the gun created feelings of helplessness, she said.

“Any reference to it would make me comply,” Beverly said. “I knew if he was going to kill me that would be the most likely way he would do it.”

She said she feared her husband would try and kill her the moment she left. It took months to create a plan with her mother in which she believed she could leave safely, without being shot or worse.

Beverly had good reason to be afraid. Most victims who are killed by intimate partners are murdered while attempting to leave, Sorenson said. Her findings illustrate just how powerful firearms are in trapping women in abusive relationships.

“If you have an intimate partner who has threatened you with a gun, leaving is incredibly difficult,” she said. “A person might decide to stay there and stay alive.”

Women are far less likely to fight back when a gun is present, she said, and are more likely to do what the abuser says to stay safe.

Sorenson’s findings show the real need to remove guns from abusers. Domestic violence victims are five times more likely to be killed if their abuser has access to a gun, according to one study. And they frequently are. Every 16 hours, a woman in the U.S. is killed by an intimate partner wielding a gun.

Under federal law it’s illegal for convicted domestic abusers to own or purchase firearms. But in practice, many states lack enforcement mechanisms to separate abusers from the guns they already a own.

Shannon Watts, founder of Moms Demand Action, which is part of Everytown for Gun Safety, said Sorenson’s study provides even further evidence that gun violence and domestic violence doesn’t always look like someone being shot.

“Injuries and homicides are just the tip of the iceberg,” she said. “We may be missing many common ways that guns are being used to perpetuate abuse, whether it’s physical or mental.”

It’s been 8 years since Beverly left her husband. She’s still living in Michigan, and her ex-husband is currently in prison on aggravated stalking charges. She said she is still terrified of him and what could happen if he gets out on parole.

“I know how easy it is to obtain a gun legally and illegally,” she said. “I take all of his previous threats very seriously.”

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Melissa Jeltsen covers domestic violence and other issues related to women’s health, safety and security. Tips? Feedback? Send an email or follow her on Twitter.

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