On a recent outing with a friend, I listened as she jumped through hoops on the phone with her less-than-appreciative husband. When I pointed out that I thought she deserved better, she shrugged it off and gave me the old “That’s just how he is,” excuse.

She gives. He takes. And apparently, this pattern is quite common in relationships between co-dependents and narcissists.

“The co-dependent person who feels the need to nurture and take care of someone will always be drawn to the narcissist,” said Ross Rosenberg, a psychotherapist and author of “The Human Magnet Syndrome: Why We Love People Who Hurt Us” (Premier Publishing & Media.) “They habitually give all their love, respect and caring to another person without getting the same in return.”

While the term “narcissist” is used ad nauseam these days, Rosenberg said it’s important to know the difference between someone who is self-absorbed and someone with mental illness.

“There’s Narcissistic Personality Disorder and then there’s this term narcissism, and the two get mixed up,” Rosenberg said. “A narcissist is someone who is self-centered and self-focused. Narcissistic Personality Disorder (NPD) is a mental illness.”

So how do you know if you’re dealing with a common narcissist or someone with NPD?

“In a relationship, the NPD gives no authentic and unconditional love, respect and care to others, and they don’t think they should,” said Rosenberg. “They may give the co-dependent just enough affection so they stick around, but that’s just so they get something in return.”

Narcissists will actually choose a co-dependent intentionally by their low self-esteem, or what Rosenberg calls Self-Love Deficit Disorder (SLDD).

“People with self-love deficit are the ones saying they’re ‘sorry,’ they tend to smile when they talk about things that upset them, they’re always the one taking care of people and they feel bad if they make a mistake,” Rosenberg said. “They learn in their childhood that it’s not safe to be themselves and they grow up serving narcissists.”

Rosenberg said this co-dependent/narcissist dynamic could play out in any relationship — family, lovers, friends and even colleagues. And while a narcissist is unable to get better because they don’t think they are at fault, a co-dependent can be healed. But it requires making some life changes.

Here are some tips to stop the cycle and embrace healthy relationships:

Know your limits

“When you’ve finally had too much pain and suffering at the hands of narcissists… and you accept it and realize that narcissists aren’t loving you for who you are, but for what you do for them, that’s when you finally recognize you don’t want to live with people who treat you badly,” Rosenberg said. “This could be a break-up or a divorce, but you have to hit rock bottom before you can start the process to heal.”

Understand the root cause

“Both the person with self-love deficit and the narcissist are who they are because of early childhood attachment trauma,” Rosenberg said. “The lack of bonding and nurturing during critical stages of their child development causes this.”

Get help

“The reason people go from one bad relationship to another is because they’re repeating what they learned as a child,” Rosenberg said. “To break that habit is to understand that you were hurt really badly as a child and learned incorrectly about what love is about, and you have to choose to break the pattern. Go into therapy to solve and heal those wounds. Otherwise you will keep repeating what’s familiar.”

Talk therapy isn’t enough

“It’s hard to reverse something with just regular talk therapy because you have to be able to resolve the psychological wounds that created it,” Rosenberg said. “I think psychotherapy is the primary tool to solve the problem. Other things will help — whether it’s meditation, nutritional, spiritual care — all of that helps someone love themselves more. The goal is to reverse why you don’t love yourself. Anything that builds you up and makes you feel better — that is about you and for you — that is recommended.”

Self-love is not selfish

Those who practice self-love have what Rosenberg calls a “narcometer,”which he describes as an alarm system or “intuitive feeling” that narcissists are dangerous.

“People who have self-love and are healthy, they feel very uncomfortable around narcissists,” Rosenberg said. “Those who lack self-love were raised in an environment where they were rewarded for ignoring their own needs and they bring that into adulthood. If you’re going to help your kids, whether they’re 8 or 48, you have to learn about self-love and be a role model.”