Although the New York mayoral candidate Anthony Weiner is unlikely ever to trouble British voters, that is not to say Mr Weiner can be filed away, with complete confidence, under the category "US politicians who have incautiously disseminated images of their private parts, using the alter ego Carlos Danger". For one thing, given the reach of social media, and the man's irrepressible ambition, it must only be a matter of time – unless some sort of technology can be invented to block transmission – before a young British subject, switching on her telephone, suddenly finds that she is Carlos Danger's latest penis pen-pal.

In the more immediate future, it seems quite likely, should Boris Johnson stand again, that Londoners could soon be asking related questions about sexual behaviour and fitness for office. Has Weiner really done enough, with his lame "sexting", to be considered a serious contender? In London, evidence of vigorous and sustained priapism has become so strongly associated with mayoral ambition as to be pretty much a prerequisite for office.

Long before Boris Johnson showed the world how to brazen out a vibrant history of extramarital impregnations and assignations, both short and long term, Jeffrey Archer, the perjurer and prostitute's john, was the Tories' favoured candidate, followed by a man actually nicknamed "Shagger". Shagger was beaten by Ken Livingstone, an unlikely but notably successful ladies' man, whose idea of drinks party chit-chat, awed Guardian staff once discovered, is the line, delivered with tremendous nasal authority: "When a woman opens her heart she opens her legs."

Until last week Mr Weiner appeared to be getting an equally tolerant hearing in New York. He had become a mayoral candidate having been forced to resign from the US Congress, in 2011, after sending photographs of his penis to, he finally admitted, "about six women". He said he would seek "professional treatment". Announcing his candidacy in May he asked for a second chance and let it be known, via an emotional, New York Times interview, that he had undergone therapy. And before he was exposed as Carlos Danger, his comeback suggested considerable acceptance of ostensibly resolved sexting issues. Weiner was ahead in the polls when news broke, last week, of another, illustrated, six-month, "cyber liaison" forged on a website called the Dirty, which seems to have coincided with his period of supposed penitence.

Within days, the Carlos conquests had multiplied to three; at least, Mr Weiner said, comfortingly: "I don't believe I had any more than three."

Even then, some reporters' questions suggested that, if Weiner's conduct could be defined as an illness, some further extenuation might be available. Was he in therapy? Was his difficulty, as many have speculated, sex addiction? Although Mr Weiner demurs – "I don't believe it is" – this could well be a reluctance to over-dramatise activities he has characterised as "background noise"?

For Weiner has been happy to exploit, as a token of his seriousness about rehabilitation, the language of addiction, therapy and recovery. "I worked through these things," he reminded a press conference.

He had professional help, he went on a journey to triumph over a problem that, if not actually that big a deal, was way more complicated a tale, you gathered, than some undignified urge to get pervy with strangers.

If his Carlos problem needed "work", as well as acknowledgement, then the public probably owes Weiner the same kind of support it has previously extended to alpha sex addicts such as David Duchovny, Tiger Woods and Michael Douglas, and our own premier sufferer, Russell Brand, former owner of "a harem of about 10 women, whom I would rotate in addition to one-night stands and random casual encounters".

"I think there is such a thing," Brand writes in My Booky Wook . "Addiction, by definition, is a compulsive behaviour that you cannot control or relinquish, in spite of its destructive consequences. And if my life proves nothing else, it demonstrates that this formula can be applied to sex just as easily as it can be to drugs and alcohol." Neuroscience, on the other hand, tends to take issue with Mr Brand's analysis of his harem-keeping. Recently, sex addiction was excluded from the DSM 5, the US manual of mental disorders, along with behavioural addictions to food, the internet and caffeine.

"We looked at sex addiction," said one of authors, "but there was no science at all. None."

Now a new study casts such doubt on previous assumptions about sex addiction that questions are even being asked about Boris Johnson's alleged satyriasis. Could he be, in fact, normal? Shouldn't NHS Choices take another look at its claim, on its sex addiction page (with hilarious, addict-face illustration) that: "This addiction is similar to substance abuse because it is caused by the powerful chemical substances released during sex."

Who wrote that – Tiger Woods?

Because researchers at UCLA tested brain activity in self-diagnosed hypersexual people and found no evidence to separate their participants' reactions from those of normal people with a high sex drive.

"One of the frequent critiques of sexual addictions is that it pathologises normative, socially unaccepted, sexual behaviours," say the authors. "These data appear consistent with that perspective."

For sufferers such as Duchovny, Sheen, Douglas et al, their feelings on discovering that their affliction is no more than a culturally constructed disorder designed to buttress sexual norms can only be compared to the female shock and fury each time that another cherished diagnosis, PMS, is discredited, as a convenient means of portraying women as hormonal nutters.

What will the sex addicts do now? If celebrities must quickly find an alternative to incarceration in a private clinic, as the immediate response to a sex scandal, the de-addicting of compulsive sexual behaviour also leaves civilian sufferers without an accessible, 12-step approach to their troubles, one that a US psychologist has disparaged as "the addiction made me do it".

Beyond that, it's hard to see the disappearance of sexual addiction from the lexicon of celebrity/political excuses as anything but an advance. Not only because of the lack of physical evidence for sex addiction, but because any definition of out-of-control sex must relate to social norms.

When harems were in, for example, Brand's outfit might have been quite appealing. Compared with Boris, or Clinton or Berlusconi, or even John Major, Weiner, phone sexing in his bedroom, is Saint Anthony of the Dirty; US politics' answer to Nicholson Baker.

Suppose Weiner had not had, at his disposal, the routine narrative of inexplicable compulsion followed by much work and hard-won redemption, the public might have had to consider the gravity of his online experiments, their implications for his politics and, given that she has volunteered for popular inspection, for his wife.If diagnoses of sexual addiction help promote repressive or unrealistic definitions of normal sexual behaviour, they also provide a watertight defence against allegations of betrayal: "God knows – I must have been mad." © Guardian News and Media 2013