Former representative Anthony Weiner (D-N.Y.) was sentenced Sept. 25 to 21 months in jail for transferring obscene material to a minor. (Peter Stevenson/The Washington Post)

Bill Clinton. John Edwards. The married governor who disappeared with his girlfriend. The kissing congressman.The airport bathroom congressmanThe senator who used prostitutesThe governor who used prostitutes. And Anthony Weiner.

It isn't as if politicians don't have object lessons to learn from — there are plenty of predecessors whose sexual escapades cost them big, sometimes ending their careers or marriages.

So why risk it?

Robert Weiss, a sex and tech addiction expert for Elements Behavioral Health addiction treatment centers, says many do because that's the nature of addiction — otherwise rational people making irrational decisions to get a brief moment of fulfillment.

Weiss has not treated nor met Weiner and is certainly not diagnosing the former congressman with anything here. Weiner's wife — and top Clinton aide — Huma Abedin announced Monday they were separating after he was caught for the third time sexting other women. Weiss says the sort of behavior Weiner displayed fits a well-established larger pattern: politicians making poor decisions for momentary satisfaction, at the risk of long-term public humiliation for themselves and their loved ones.

To get a better sense of sex addiction and how it sometimes manifests itself among political types, we spoke to Weiss. Our conversation has been lightly edited for length and clarity.

Is there a common connection we can draw among these men?

These are men, people in highly visible roles that may not be only interested in that political role, and they want to be seen, they want to feel important. So there's a narcissistic element to this. And then they get in these stressful roles, and they end up in unhealthy situations.

So how do you know if someone is a sex addict? 

There are three basic criteria for any addiction, whether it's substance or behavior:

1. Loss of control: The person says, "I'm not going to that dealer or that casino or not going to buy another gallon of Häagen Dazs," but they do it anyway.

2. Continuation of behavior despite adverse consequences: This person has a DUI, they lost their job, or their wife left them, and they are continually doing similar poor behavior despite all that.

3. Preoccupation or obsession with the substance or behavior: The addiction comes first. When someone is sexting and their kids walk in, they're not thinking about the kids. Addiction is not a thinking disorder, it's an emotional disorder. So it doesn't matter how smart you are, how much money you have or how attractive you are. It's about being emotionally broken and constantly needing stimulation.

And I would assume that these emotional disorders have their roots in past emotional experiences? 

People often have very early trauma, various kinds of sexual trauma and neglect. I've seen captains of industry and famous people who have incredibly beautiful wives. It isn't about that. It's about emotional emptiness and being broken inside. And in that moment, when that person is needful of getting this specific kind of validation and stimulation, nothing else matters.

But I want to explain this: If I'm working with a drug addict and he doesn't have drugs for a week and his boss calls him in the morning and says he's going to get paid that day, and he calls the dealer and makes plans to get drugs that afternoon, that addict is already in an altered state of consciousness. He's aroused, he's excited, he's euphoric. If I measured his heart rate, his breathing pattern, they'd all be changing as he's heading downtown to get the drugs. So when he gets the drugs, at what point was he high? Was it at 4 p.m. when he inhaled? Or was it when his boss called him in the morning?

We know that the anticipation of fantasy plays a big role in sex addiction. It's about hyperstimulation and living in the excitement of that — what the other person looks like, what they'll be saying, what they'll be doing, what they'll be wearing.

My clients will spend a week texting someone and then spend 10 minutes having sex with someone. My clients are not in it for the sex. They're in it for the distraction, the escape.

So sex addiction isn't about sex?

No. It's about people who use intense fantasy to escape. When most people have a bad day, they turn to a good friend, they take a hot bath, they do some exercise, they swear at the dog. The people I work with seek to isolate themselves and get into hyperstimulation, because they've often been taught people are unreliable.

This is not about sleaze. This is about sadness, pain, brokenness and what can happen to a family when this kind of issue goes untreated.

Maybe I'm not paying attention, but it seems like only recently the term 'sex addiction' has made its way into the public sphere.

We don't have a diagnosis for sex addiction. It's not in the [Diagnostic and Statistical Manual of Mental Disorders]. (It got taken out three years ago over political decisions.) It's going to take time for there to be a shift in how we look at sexual behavior. It's going to be a while before we can clinically diagnose sex addiction without prejudice, before we can view sexual behavior in that way in America. Because there is so much morality that gets in the way.