After TLC star Josh Duggar was accused of sexually abusing his young sisters, his parents said their son had repented for his "very bad mistakes." But those who have been through similar experiences say what happened to them was much more than that.

Facebook: duggarfamilyofficial The Duggar family.

When Rebecca Trovitch was about 8 years old, her 12-year-old brother began coming into her room at night and sexually assaulting her. The abuse continued for about a year, but she never told a soul. For the next few decades, the secret of what happened ate away at her. It wasn't until Trovitch told a therapist about the abuse three years ago that she finally felt some relief. "This has been the first time in my entire adult life that I didn't think about it every single day," Trovitch, now 39, told BuzzFeed News. Stories like Trovitch's are sadly much more common than many people realize. Evidence suggests that one is more likely to be sexually abused by a sibling than a parent. "It is estimated that between 40% and 60% of intrafamilial sexual abuse occurs between people from the same generation," John Caffaro, a professor at the California School of Professional Psychology and the author of Sibling Abuse Trauma, told BuzzFeed News. "Estimates are that approximately half of all adolescent-perpetrated offenses involve a sibling." The issue of sibling sexual abuse was thrown into the national spotlight last week after allegations emerged against Josh Duggar, who stars with his parents, Jim Bob and Michelle, and the rest of his family on the TLC show 19 Kids and Counting.

Facebook: ja20com Josh Duggar and his wife Anna.

According to a police report obtained by InTouch Magazine, Josh was accused of sexually assaulting five female minors, including some of his younger sisters, when he was 14. He allegedly did so while the girls were both asleep and awake. Duggar, now 27, released a statement on Thursday along with his parents and wife Anna in which he admitted to behaving "inexcusably" and said he has apologized and received counseling. "I sought forgiveness from those I had wronged and asked Christ to forgive me and come into my life," the father of three wrote. "I would do anything to go back to those teen years and take different actions." Jim Bob and Michelle Duggar said that their son "made some very bad mistakes." "We had tried to teach him right from wrong… We pray that as people watch our lives they see that we are not a perfect family," they wrote. Abuse survivors and experts told BuzzFeed News the Duggars' description of the abuse as a "mistake" diminishes both the effect on victims and the seriousness of the crime. "I wouldn't say it's a mistake, I would say it's sexual abuse, something that is such a serious crime," one survivor of sibling sexual assault, who wished to remain anonymous, told BuzzFeed News. "You say, oops I dropped my coffee, that's a mistake." Professor Caffaro agreed, telling BuzzFeed News that the incidents described in the allegations against Josh Duggar are "clearly more than a 'mistake.'" "[The abuse] potentially signals the presence of individual psychopathology, developmental trauma, and significant family dysfunction," he said.

It's completely normal for children to have sexual curiosity, Caffaro said, but it is often hard for parents to tell when that curiosity crosses a line into abuse. A few factors can indicate something darker is going on, according to Caffaro. For example, abusers are often much older than their victims and may engage in "coercion or manipulation" to get their way. This includes abuse that happens while the victim is unconscious, he said. The family environment can also play a factor in sibling sexual abuse. Research suggests this type of abuse is more common in large families where there are blurred lines between who is a parent and who is a child, Caffaro said. "Emotionally and/or physically absent parents may empower older siblings to assume parental roles," he said. Parents in these types of families are also more prone to dismissing the abuse, he said. "If sexual behaviors are noticed, they are likely to be minimized and misinterpreted as a normal aspect of childhood development," Caffaro said. Young sexual offenders are a diverse group and have widely differing motivations behind their acts of abuse. These can include sexual curiosity, an attempt to violate their siblings' rights, and mental health issues. However, in at least one study, youth sex offenders who violated their siblings were found to be at a higher risk for re-offending than those who violated a non-sibling. "Overall, research on adolescent sexual offense shows that treatment outcomes for youths who offend sexually are improved greatly if family is involved in the treatment process," Caffaro said. Caffaro could not discuss the Duggar case specifically, saying he would need more information about Josh Duggar, what counseling he received, and his family to know his chances for rehabilitation. In the police report, the Duggars told authorities they had sent their son to a Christian program involving hard work and counseling, but later revealed they sent him to help a friend who acted as a mentor to him. It has also emerged that the family were advocates of a home schooling program that contained deeply troubling advice on how to handle abuse. The Springdale, Arkansas police department did not learn of the incidents until 2006, over three years after they allegedly occurred and after the statute of limitations had expired. Caffaro said that parents facing a situation similar to the Duggars should know it is imperative they immediately report the incident to their local child welfare or child protection agency if the offender is under 12. If the offender is over 12, they should contact the police. "Admitting to yourself that sibling sexual abuse might be happening in your family can be hard," he said. "Admitting it to someone else can be even harder. The important thing is to get help."