Men and women with post-traumatic stress disorder (PTSD) may also experience sexual dysfunction and relationship difficulties, a new research review suggests.

"Persons with PTSD often complain of sexual dysfunction and problems with intimacy more generally," and there's increasing evidence to support this association, said lead study author Rachel Yehuda in an email.

About 6 percent of men and 13 percent of women will experience PTSD at some point in their life, Yehuda and colleagues note in the Journal of Sexual Medicine. Triggers for the condition include exposure to actual or threatened death, serious injury or sexual violence, as well as witnessing a loved one endure this kind of trauma.

Symptoms can include recurrent flashbacks and nightmares; instinctive avoidance of situations that might trigger a reminder of the trauma; emotions of guilt, shame, anger or feelings of alienation and disinterest in previously enjoyable activities; as well as changes in arousal and difficulties with concentration and sleep.

Until recently, sexual dysfunction has been linked to exposure to rape or sexual trauma rather than to the presence of PTSD. But in their review of recently published research on this connection, Yehuda and colleagues concluded that sexual difficulties in PTSD may occur as the brain connects the sensation of arousal to aggression instead of healthy sexual function.

Yehuda, a mental health researcher at the James J. Peters Veterans Affairs Medical Center and the Icahn School of Medicine at Mount Sinai in New York City, said in her email that while women are more likely to experience rape and men are more likely to experience combat trauma or physical assault, they can both experience sexual dysfunction linked to PTSD.

"Although it makes sense that a person – man or woman – who experienced sexual violence would have sexual dysfunction, trauma survivors with PTSD from other experiences also have sexual dysfunction," she said. "It does not seem to be the case that the problem stems from the type of trauma."

For example, one study of more than 4,500 military veterans who'd served in Afghanistan and Iraq found that PTSD was a significant risk factor for sexual dysfunction. Another study of about 370 men on active duty or recently separated from military service found that PTSD increased the likelihood of erectile dysfunction 30-fold.

Many PTSD symptoms are incompatible with feelings of pleasure, intimacy, trust and safety, the researchers note.

Both sexual activity and PTSD involve physiological arousal. But when people with PTSD experience arousal, they may also have an involuntary reaction that makes them feel fearful or threatened and that impedes healthy sexual function, the researchers write.

At the same time, they add, it's possible that the loss of libido experienced by people with PTSD might be connected to depression or another mental health disorder.

Depression, as well as medications used to treat it, can contribute to sexual dysfunction, Dr. Benjamin Breyer, a researcher at the University of California, San Francisco, said by email.

"If someone has PTSD and is getting medicines for treatment, it makes sense to examine what is being given and to determine if adjustments that (cause) fewer sexual side effects can be made," said Breyer, who wasn't involved in the study.

Treatment for men and women who experience a traumatic event should include explanations of the potential for sexual dysfunction. "Educating patients and trying to remove the stigmas associated with sexual dysfunction is important so people who suffer from sexual dysfunction actually get treatment," Breyer said.

Explaining the biological connection between PTSD and low libido or difficulty with intimacy can also help partners or spouses support a loved one who is experiencing sexual dysfunction, Yehuda said.

She added that her team hopes to encourage more research and promote broader discussion of these issues during therapy.