A 2016 article in The Australian says that there is an increase in youth ED, and furthremore that it's due to porn:
You couldn’t make it up, right? Wrong: erectile dysfunction in men in their teens and 20s — coupled with an inability to maintain erection or achieve climax — is now “massive”, according to a leading sexual psychotherapist.
“The number of young men with performance issues has escalated in the last five years,” says Angela Gregory, who has treated men with erectile dysfunction for 16 years at Britain’s Nottingham University Hospital.
“Historically this was men in their 40s and 50s with underlying health issues: cardiovascular disease, diabetes, ME (myalgic encephalomyelitis) or prostate issues. Now I see as many men in their 20s — the split is equal. This is a massive thing.”
The cause? The tidal wave of readily available online porn and the demands it is placing on generation XXX.
“ ‘Are you watching online porn?’ is now one of my main assessment questions,” Gregory says. “And the answer is almost always yes. Some can’t achieve erection, but it also (causes) inhibited or delayed ejaculation.
“One young man has women throwing themselves at him. But he finds it overwhelming that men are expected to perform like porn stars. Lots of young women now want porn sex and these guys are either not equipped to deal with these demands or don’t want to.”
And while we’re familiar with revenge porn, Gregory is hearing from an increasing number of men who are “impotency shamed” by their girlfriends on social media. “On about 10 occasions I’ve talked to men who have been outed on Facebook, Twitter, Snapchat or Instagram for not being able to sexually perform,” she says. “Everybody in their peer group gets to know they’re a failure. For a man that’s devastating. These men are retreating from normal relationships.”
Gregory says some young men can’t achieve erection because their brains’ dopamine centres have been effectively rewired by porn, meaning real girls cannot compete with the hyper-stimulation of porn.
For this Skeptics question, I'd be satisfied if this surge in youth ED is confirmed/analyzed from multiple studies, preferably with representative samples, and preferably in the most systematic way, i.e. meta-analysis. I'm not really asking the sub-question whether this claimed surge really is due to porn... cause and effect may be harder to prove; one usually needs more than epidemiological studies for that. I just want to know first if the purported effect (increase in youth ED) is undoubtedly real.
And by the way, there is a question here whether porn can lead to ED... the top-voted & accepted answer is negative, based on two or three studies. So, that's an additional reason to try and separate the claim of increase in youth ED vs. what might have caused it.
A similar story has appeared in the Express:
Exposure to images and films is de-sensitising men in their late teens and early 20s, leaving them unable to get aroused in the bedroom, experts have revealed.
They said part of the problem is porn is immediate accessible on smartphones and tablets.
Erectile dysfunction (ED), also known as impotence, is the inability to get and maintain an erection. It is a common condition in older men but uncommon in younger men.
However, Angela Gregory, a psychosexual therapist, said she has seen a surge in young men attending her clinic at Nottingham University Hospital.
What I've seen over the last 16 years, particularly the last five years, is an increase in the amount of younger men being referred," she said.
"Our experience is that historically men that were referred to our clinic with problems with erectile dysfunction were older men whose issues were related to diabetes, MS, cardio vascular disease.
"These younger men do not have organic disease, they've already been tested by their GP and everything is fine.
"So one of the first assessment questions I'd always ask now is about pornography and masturbatory habit because that can be the cause of their issues about maintaining an erection with a partner."
A third story not relying on the same UK data came from an Italian clinic:
In our Sexual Medicine and Andrology Unit, established in an Endocrinology setting at the University of Florence, medical consultations for younger men are infrequent, with a prevalence of men aged less than 40 years at only 14.1% of more than 3,000 men complaining of ED. However, when considering the new referrals to our Unit during the last 6 years, we can notice a progressive increase in prevalence of men below 40 years seeking medical care for ED (Figure 1). According to these data, ED is becoming a common concern even among young men, and the clinical practitioner in sexual medicine must become aware of how to manage the problem and avoid underestimating a symptom.
So this does raise the question whether it is a Europe-wide phenomenon, restricted to some countries, etc. I'm also going to say that going just by who shows up the clinics (instead of representative samples) risks a form of Berkson's paradox.