Transcript for The Teenage Brain on Porn

When we hear about celebrities claims to be addicted to sex there's a collective eye roll. When it comes to porn, there's increasingly concrete evidence, science, that the addiction can be real. And as powerful as drugs and alcohol. For many kids that can easily access porn from their computers and smartphones it can go well beyond just a dirty habit and become a dangerous one. Here's abc lindsay davis. Reporter: According to one study, 7 of 10 teens have accidentally stumbled across porn online. But experts are asking is the average teen really ready for this? Hard-core porn. Right on my phone for anybody to access. Reporter: We also suspected porn can't be good for the teenage brain but tonight a new study. Is there now scientific evidence to back that up? When you put porn into google, what does he think is going to come up? Probably pictures of make a naked woman. He's account putted into a woman of sexual violence. Reporter: Gail, the author of a book called "pornland" says for this the average teenage boy porn is his first formative impression of sex. He doesn't have a reservoir of his own experience of sexuality with other people. He's probably never had sex with another human being. Reporter: And not just boys. This girl was only 12 years old when she shockingly admitted she's not only seen porn but she understood all the innuendo. It says if you dress this way you'll be treated well or you'll be powerful. Sex is powerful. Reporter: Wshe's part of this new order of teens showing that exapproximately sit images can be found anywhere. There's no one before us. We're the first to have what we have and there's no one before us to guide us. We are the pioneers. Reporter: And these images can be traumatic. Her friend, danielle, first learned about sex on a porn site. One black guy and what spannic guy and this blond woman and they were ferociously banging each other. It was very -- I mean, I came home and I was balling my eyes out. I'll never forget it. Reporter: Not surprising these images often color teens ideas of what sex should be like. Caleb is a young man from england with a long-time porn compulsion and he grew up with english journalist saying he's had sex with women and it just doesn't compare. It's not as good because they're not as good as the porn. The porn goes into a lot more. Reporter: And with pornography so ever-present, some teens become addicted to it. Sometimes, at heartbreakingly young ages. From 12 to 13, all the way up to 14, it was kind of there, uninterrupted. I became almost numb to it. It became such a part of my, pretty much which daily routine. Reporter: Nathan, a teen in utah, eventually admitted to what was going on to his parent tsz and was ultimately able to quit but for others it's not that easy. I startsed to isolate myself because I hated what I was doing. I hated that I couldn't stop. Reporter: Breeian is now 23 but remembers how strong her addiction was during all of her high school years. I would say that this is something that was not just me. I knew tons of students who were in my grade, my peers, who were doing the same thing. Reporter: Far caleb he said it crept up on him. At first I didn't know the limits and the bounds of what was extreme. So with friends and I'd find out how much they view porn. And it just didn't compare. Like every day I was watching porn. Reporter: We spent a day with him to see the problem first hand. Why do you think you have this relationship with porn? I don't know. It just seemed -- it was just something that my brain must have picked up. I can't find a way to stop. I tried getting rid of my smartphone. How do you get over that low? Reporter: He gets a glimpse of his hard-fought struggle when they drive past a pretty girl and it immediately triggers a reaction. Just going to go for a look. There he goes. Better? Yeah. So annoying afterwards. How do you feel now? Pissed off. Why? For that split second, I just feel like the best thing to do and as soon as I've finished I'm like why the did i just do that. That sounds like a drug addiction. It is, virtually. I can't stop it. Reporter: But if the internet porn compulsion the same thing as a true clinical addiction? Does it actually change a person's brain? This doctor, a nur r neuropsychiatrist working at cambridge university tried to find out. I wasn't sure what I would find but in part because we know so little about this. In these images you can see the pleasure centers of an addict's brain responding to their drug of choice. With scans of young people with a porn compulsion show the same result. She found 20 young men between the ages of 19 and 34 whose lives were so controlled by porn they were willing to be a part of the study. They didn't want to be identified but they were willing to be scanned and compared to a control group of volunteers. The subjects were shown images of explicit porn to see if their reward centers would respond in the same way as drug users. When the data was analyzed the results were astounding. We see a very clear increase in activity in the reward center. Reporter: The compulsive user's reactions were twice as active as those in the control group in the pleasure center, known as the striatum, matching the responses of drug and alcohol addicts. Compulsive pornography users have parallels with substance abuse disorder. Reporter: One study is not definitive and the frayed group for the porn industry says unlike drugs and alcohol, adult content is not and cannot be a chemical addiction no more than compulsive shopping, gaming or hoard. But even if we assume it's an addiction what's the cure? A former ad exec turned entrepreneur think she has a solution. Replace hard-core online porn with images of real love-making. She started a website calmed "make not porn" a kind of youtube video streaming channel online where real life couples give office a peek beneat their sheets. The site went public in january and already has more than 100,000 users. Children are viewing hard-core porn years and years and years before they'll have their own sexual experience and it's shaken their view of what sex is. That's why what we're doing is so important. Reporter: Other producers like this director are making what they say are softer, more relatable depictions of sex. Porn is a fantasy. And it can't ever stand in as sex education. Reporter: But for the kid who is view these hard-core images, they can be difficult to erase from the brain. For this girl, these pictures that many kids so too many of too soon, simply don't translate to true life or true love. Parents are able to talk to their children about what real love and real sex later on is. Most of the kids I know would trust our parents over two porn stars that we've never met. For "nightline" I'm lindsay davis in new york.

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