Pornography is a loaded subject. Opponents argue that it can ruin marriages, lead to sexual addiction or other unhealthy behaviors, and encourage sexual aggression.

Proponents claim that erotica can enhance sex lives, provide a safe recreational outlet and perhaps even reduce the incidence of sexual assault. (After pornography was legalized in Denmark in 1969, for instance, researchers reported a corresponding decline in sexual aggression.)

But in some ways, both arguments are moot: Whether or not you think it's moral, the fact is, people like porn. Various international studies have put porn consumption rates at 50 percent to 99 percent among men, and 30 percent to 86 percent among women, according to Gert Martin Hald, PhD, and colleagues in The APA Handbook of Sexuality and Psychology (Vol. 2).

"Porn is practically ubiquitous," says Ana Bridges, PhD, a psychologist at the University of Arkansas. And the Internet has made it easier than ever to get an erotic fix. The late sex researcher Alvin Cooper, PhD, called this the "triple-A engine" effect: The accessibility, affordability and anonymity provided by the Web have put adult content right at our fingertips.

Many people argue that's a good thing. In a 2002 survey conducted for PBS/Frontline by the Kinsey Institute for Research in Sex, Gender and Reproduction at Indiana University, 86 percent of respondents said porn can educate people, and 72 percent said it provides a harmless outlet for fantasies. Among those who reported using pornography, 80 percent said they felt "fine" about it.

"There are a lot of people out there using a lot of porn who have no problems with it whatsoever," says Erick Janssen, PhD, a senior scientist at the Kinsey Institute. "So when does it become an addiction?"

That, of course, is a key question for researchers trying to understand pornography's dark side.

Real-life relationships

While many viewers of adult content don't seem to suffer ill effects, porn can become problematic for others. The Kinsey Institute survey found 9 percent of porn viewers said they had tried unsuccessfully to stop.

When pornography use becomes excessive, romantic relationships can suffer. Destin Stewart, PhD, and Dawn Szymanski, PhD, at the University of Tennessee, Knoxville, surveyed female college students and found that those who perceived their boyfriends' porn use to be problematic experienced lower self-esteem, poorer relationship quality and lower sexual satisfaction (Sex Roles, 2012).

But it's not always that simple. In a 2013 study, researchers at Brigham Young University and the University of Missouri surveyed heterosexual couples who were married or living together and found that men's use of porn was associated with lower sexual quality for both men and their partners. Female use of porn, however, was associated with improved sexual quality for women (Journal of Sex Research, 2013).

Bridges and Patricia Morokoff, PhD, reported similar findings: When men used porn, they tended to report lower levels of sexual intimacy in their real-life relationships. When women used porn, however, intimacy increased (Personal Relationships, 2011).

Bridges points to two possible explanations for the finding. First, she says, while men tend to view pornography solo, women are more likely to watch it with their partners in a shared sexual experience. "This was something that they incorporated into their lovemaking ritual," she says.

Also, men and women typically use different types of porn. Men are more often drawn to videos showing sex acts absent of context. "You might not even see anybody's face," she says. Women, though, tend to watch "couples porn," with story lines and softer angles. "When partners use porn together, they tend to watch things where both people are more egalitarian participants in a sexual act," Bridges says.

Although some couples seem to benefit from pornography, that's not the case for everyone. When one partner uses porn at a high frequency — typically the men in the heterosexual couples Bridges has studied — there can be a tendency to withdraw emotionally from the relationship. Those men report "increased secrecy, less intimacy and also more depression," she says.

It's not clear, however, whether pornography is the proverbial chicken or the egg. Does a person turn to pornography because he's already in an unsatisfying relationship? Or do women pull away and lose interest in sex when they discover their partner is spending quality time with adult film stars?

Bridges says both scenarios are probably true, based on the couples she's interviewed. And indeed, the two scenarios tend to feed off each other. If a couple goes through a dry spell, the man may watch more porn to fill the void. Some women may feel threatened or confused by that response. They often report feeling less attractive, like they could never measure up to the X-rated actresses. The result: even less sex, even more porn and a relationship that continues to falter.

Bridges is now testing interventions to help men curb their excessive pornography use, primarily using cognitive-behavioral interventions. Eventually, she hopes to develop a couples-based treatment manual to help both partners come to an understanding — one that may or may not include pornography.

Addicted to love?

Relationships aren't the only area where compulsive porn use can be damaging. Psychologists describe anecdotal reports of people losing their jobs because they couldn't control the urge to visit adult websites at work, for instance. "When porn use becomes so intense in frequency or duration, it starts to interfere with the other aspects of a person's life," Bridges says.

However, experts disagree over how to classify excessive porn use. "We're still not completely sure what this behavior is," says Bridges.

When the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was being drafted, experts considered a proposed diagnostic addiction called hypersexual disorder, which also included a pornography subtype. But in the end, reviewers determined that there wasn't enough evidence to include hypersexual disorder or its subtypes in the 2013 edition.

If compulsive pornography use is not a hypersexual disorder, could it be considered an addiction akin to drug or alcohol addiction? That's what Valerie Voon, MD, PhD, a neuropsychiatrist at the University of Cambridge, is exploring. By scanning the brains of compulsive porn users with MRI while they view erotic images, she's testing whether they show brain activity patterns similar to substance abusers viewing beer bottles or drug paraphernalia.

So far, the brains of compulsive porn users resemble the brains of alcoholics watching ads for a drink, reports Voon in a 2013 British documentary called "Porn on the Brain."

Despite her early findings, Voon says it's probably too early to put compulsive porn users in a box with people who suffer from drug or alcohol problems. "We need more studies to clearly state that it's an addiction," she says.

Other research has turned up contrary results. Nicole Prause, PhD, a researcher in the department of psychiatry at the University of California, Los Angeles, and colleagues recently studied brain responses in people who have trouble regulating their porn consumption.

Prause used EEG to measure a brain response known as P300, which is a component of the brain's electrical activity that occurs about 300 milliseconds after viewing a stimulus. This activity increases when people are emotionally engaged with that stimulus. When people with drug addictions view drug-related images, for instance, they show a clear bump in the P300 value.

Prause used three separate scales to identify people with hypersexual problems. Then she showed them a variety of images, including sexual ones. She predicted she'd see a dose response: Those people who reported having greater difficulty controlling their porn use would experience a greater spike in the P300 value. "Frankly, I thought this would be a slam-dunk easy finding," she says.

Surprisingly, that was not the case. People who reported greater problems controlling porn use had no clear change in the P300 value related to their level of sexual problems, whether they viewed porn or neutral images such as food or people skiing (Socioaffective Neuroscience & Psychology, 2013). "Our findings don't make them look at all like addicts," she says.

Meanwhile, a 2013 study by researchers at the University of Leicester in the United Kingdom suggests that a penchant for porn may be more compulsion than addiction. In a study of porn use among 226 men, the researchers found that certain traits — neuroticism, agreeableness, conscientiousness and obsessional checking behaviors — were correlated with high pornography use (Journal of Sex & Marital Therapy, 2013). Men who have trouble resisting the lure of porn websites might simply have dispositions that make them more vulnerable to compulsive problems in general, the researchers concluded.

Ensuring effective treatment

Putting a label on a porn habit isn't an idle exercise. Understanding what drives the behavior is a necessary step toward designing effective treatments for people who can't control the urge.

While science is far from settling this debate, some treatment programs continue to push the idea that porn is an addiction. "There's a tremendous treatment industry that needs this to be a disease — a thing they can charge people to treat," Prause says.

But promoting certain therapies may be ill-advised. "You can harm patients by using treatment models that aren't research-supported," Prause says.

Whether or not pornography is a diagnosable addiction, it's clear it hurts some people. For them, there just isn't much evidence about how best to control this behavior. "There is a real dearth of good, evidence-based therapeutic literature," Voon says.

A handful of researchers are working to close that knowledge gap but it's not an easy field to work in. "[Pornography] is a highly politicized and sensitive topic," notes Janssen. "It's hard to get funding for sex research in general, unless it's in the context of sexually transmitted diseases."

Prause has experienced the difficulty firsthand. While she'd be thrilled to see things change, she says, funding agencies are still squeamish about sex. "It's difficult to have it taken seriously," she says. "But it really is a science like any other."

Kirsten Weir is a journalist in Minneapolis.

Further reading

  • Bridges, A. J., & Morokoff, P. J. (2011). Sexual media use and relational satisfaction in heterosexual couples. Personal Relationships, 18(4), 562–585.
  • Steele, V. R., Staley, C., Fong, T., & Prause, N. (2013). Sexual desire, not hypersexuality, is related to neurophysiological responses elicited by sexual images. Socioaffective Neuroscience & Psychology, 3, (1–12).
  • Tolman, D. L., & Diamond, M. (Eds.). (2014). APA handbook of sexuality and psychology: Vol. 2. Contextual approaches. Washington, D.C.: American Psychological Association.