No one would be surprised to discover that Navy servicemen use porn as recreation especially on active duty away from their loved ones. However a sharp rise in sexual difficulties including erectile dysfunction (ED), delayed ejaculation, low sexual desire, and decreased sexual satisfaction during partnered sex in men under 40 is causing concern.  A new review by US Navy doctors and The Reward Foundation has been published in the journal Behavioral Sciences. Entitled Is Internet Pornography Causing Sexual Dysfunctions? A Review with Clinical Reports, the paper proposes the brain mechanisms by which internet porn use could create sexual difficulties even in healthy viewers. Those who start using during the key developmental periods of puberty and adolescence are especially vulnerable. The review is available free from here.

Traditional risk factors like diabetes, cardiovascular disease and drug use that once explained men’s sexual difficulties do not appear to be sufficient to account for this development. As recently as 15 years ago ED rates were negligible (2-5%) in sexually active men under 40. Now, researchers are reporting ED rates as high as 30% in this same age group. Many of these men appear to be able to attain erections and ejaculate when viewing porn. They only experience sexual dysfunctions during partnered sex.

It is possible that today’s internet porn is unique in its ability to condition (especially youthful) sexual arousal in unanticipated ways due to its unending novelty, video format, and the ease with which users can escalate to more extreme material. In some men, this inadvertent conditioning may be leading to sexual dysfunctions and diminished libido during sex with partners.

The study includes three case studies including one about a 20-year old serviceman who presented with difficulties achieving orgasm during intercourse in the previous six months. From having started out with soft core porn, his needs had escalated to hard core and then to fetish material in order to orgasm. He purchased a sex toy. This device was initially so stimulating that he reached orgasm within minutes. However, as was the case with internet porn, with increased use, he needed longer and longer to ejaculation. Eventually he could not orgasm at all. Upon his return from deployment, although he was still physically and emotionally attracted to his fiancée, he discovered he preferred the device to actual intercourse because he found it more stimulating. He had no history of major illness, surgery or mental health diagnoses. He wasn’t taking any medications or supplements. It was concluded that the use of the sex toy had desensitized his penile nerves and watching hard core porn had altered his threshold for sexual stimulation. A few weeks later on reexamination by the urologist, the serviceman reported that after cutting back on his porn use and cutting out use of the sex toy, he was able to have orgasms again with his fiancée and that their relationship had improved.

So what has changed?

Ten years ago, streaming internet porn (via “tube sites”) arrived representing a major change in men’s sexual environment. It appears that streaming online porn may be what Nobel laureate Nikolaas Tinbergen referred to as a ‘supernormal stimulus’. That is, it may constitute an exaggerated imitation of something our brains evolved to pursue because of its evolutionary importance – in porn’s case, apparent potential genetic opportunities in the form of novel, willing “mates”. Research shows that video erotica is more arousing than still images, and novel sexual visuals trigger greater arousal, faster ejaculation, and more semen and erection activity compared with familiar material.

Key features of internet porn (video format, endless novelty, ease of escalation to more extreme material) not only make it potentially more compelling for users, but a Cambridge team of neuroscientists also showed that novel porn speeds habituation and tolerance, which could account for the tendency of some porn users to escalate to more extreme material (to crave novelty) over time. In fact, a 2016 Belgian study reported that half of respondents had escalated to pornographic material that they formerly considered “uninteresting” or “disgusting.”

It’s possible that some users’ sexual responsivity is declining in response to too much stimulation, just as Kinsey Institute’s researchers observed a decade ago.

Kinsey Institute researchers were among the first to report porn-induced erectile-dysfunction and porn-induced abnormally low libido. In 2007, they noted that high exposure to porn videos apparently resulted in lower sexual responsivity and an increased need for more extreme, specialized or “kinky” material to become aroused, but did not investigate further. This factor has yet to be isolated and studied in depth in relation to otherwise unexplained sexual difficulties in men without mental disorders.

This new review recommends future research of this phenomenon. As clinical reports suggest that terminating internet porn use is sometimes sufficient in itself to reverse negative effects, there is a need for extensive investigation using methodologies that have subjects remove the variable of internet porn use to clarify the full range of its effects. Intervention studies (removing the variable of porn use) are needed to elucidate whether the activity of internet porn viewing is potentially risky for some users, even otherwise healthy users.

To date, this possibility hasn’t really been investigated. Indeed, it has often been presumed that only porn users with underlying mental disorders develop severe symptoms and dysfunctions. This presumption is premature, as it could be that some porn users without mental disorders, such as some of those described in the paper’s clinical reports, are developing sexual difficulties from over-consumption of today’s porn.

How can healthcare providers know if a patient’s sexual performance problems stem from internet porn use?

Traditionally, urologists assumed that if a man with ED could achieve an erection and ejaculate when masturbating, his problem was anxiety about sexual performance with a real person. However, this test can produce misleading results in young men who have been masturbating exclusively to supernormally stimulating internet porn. Even if they have no anxiety they may have conditioned their sexual arousal to screens and unending novelty, such that partnered sex doesn’t evoke the anticipated responses.

Healthcare providers might ask whether the patient with otherwise unexplained sexual dysfunctions can achieve and sustain a satisfactory erection (and climax as desired) when masturbating without using internet porn. If he cannot, but can easily achieve these goals with internet porn, then internet porn use needs to be considered a possible factor in his difficulties. If he can easily masturbate to climax both with and without internet porn, then his issue may be classic “performance anxiety” related to sex with a partner.

Finally, while healthcare providers must certainly screen for relationship problems, low self-esteem, depression, anxiety, PTSD, stress and other mental health problems, they should be cautious of assuming that poor mental health is the cause of otherwise unexplained sexual dysfunction in men under 40. The relationship between these factors and sexual dysfunction in young men may be bidirectional and co-occurring.

Incidentally, multiple studies on internet addicts and internet porn addicts have screened subjects to be certain they were free of other mental health disorders, and yet found that their brains showed evidence of addiction-related brain changes compared with control subjects. Some of these changes, such as hyper-reactivity to porn cues, may help to explain sexual dysfunctions in otherwise healthy internet porn users in the general population.

In any case, to the extent that porn-related sexual dysfunctions clear up after quitting internet porn, they were not due to mental health disorders.