"I want to run away again," says Lena. It's not the first time I've heard that sentence from her. On the contrary.

Ever since we became friends, her relationships have always followed the same pattern: the extreme rush of being in love, followed by such a bad "hangover" that she knows no other way to help herself than to ditch the guy involved.

Now, she sits in front of me again. It's been nearly five months since she got together with her new boyfriend. And she's fighting the impulse to flee.

She's bored. Things she thought were cute a minute ago... bug her now. Just the other day, she thought he was so much fun. Everything was so nice.

Lena knows this situation only too well. And this time, she wants to do it differently. She wants to stay. Because she really likes this guy. Besides, even to Lena it's clear: She can run away, sure, but this pattern will follow her — everywhere. She can't escape herself.

"Escape is really not a good solution," says couples and sex therapist Gertrud Wolf. At least not if you have an interest in understanding and changing your  behavior.

So if Lena wants to stay and break her pattern, she needs courage. Courage to face the fears that she's always running away from.

Read more: Psychology: A happy partner is the elixir of longer life

After the party

The reasons that cause people like Lena to flee are complex, Wolf says. The problems can start the moment we fall in love.

"In that phase, of falling in love, our brain is flooded with drugs," Wolf explains. "Serotonin, dopamine and opiates mix together to form a drug cocktail that would never be available over the counter in a pharmacy."

No matter how euphoric, passionate or in love we are at the beginning, the rush soon fades away. Just as every party ends at some point. The light goes on and the (sometimes painful) disillusionment follows.

"We fall in love with complete strangers these days," Wolf says, referring to digital dating platforms like Tinder. Because these love drugs cloud our brains, we don't even see who we're actually dealing with. Bad surprises are inevitable. When two people meet as friends and get to know each other, this "fall" might be not quite as deep. 

For some, however, the feeling of being in love is an irresistible attraction. The drug cocktail that accompanies it can be addictive, says Wolf. Lena, too, loves this emotional inferno: the excitement, the fun, the feeling of lightness.

The couples therapist, however, urges prudence: "I would advise someone like that not to get so deeply involved in this feeling of being in love, and to pump the brakes a little bit." She compares it to drinking alcohol: "If you have water in between, your hangover will be less severe."

Read more: Infidelity: A fling doesn't have to end everything

Attachment theory

According to Wolf, the drug cocktail works for about half a year. Then, "you have to eat chocolate again."

And not only that: "Suddenly we feel our fears again," she says. More precisely, our fear of attachment.

A fear of attachment, Wolf suspects, could also be the reason for Lena's escape behavior. "We distinguish between different types of attachment," the therapist says. Lena, she believes, could fit into the category of of people who are "insecure avoidant."

The attachment theory Wolf refers to goes back to child psychiatrist John Bowlby. It "describes the emergence and possible changes in the attachment behavior of humans."

According to this theory, eople with attachment fears have experienced at some point that, in threatening situations, they are alone with their fears. Their parents, for example, may not have their own child's distress for some reason. Comfort, or feelings of appropriate support, were missing — and still are.

The child experiences this parental behavior as rejection — a painful experience that he or she doesn't want to experience again. In the future, as these children become adults, they will therefore prefer to keep their worries and troubles to themselves and will try to avoid negative emotions as much as possible.

When fear sets the tone

"These insecurely bound people have difficulties in adulthood when it comes to getting involved and making a long-term commitment,"  Wolf says. Fear plays a major role. "Either strong fear of loss, or a great fear of becoming dependent," she says. "Mom and Dad are our first bonding partners, and they create the structures on which we build all further bonds."

Lena does get reminded of certain situations with her father when she's with her boyfriend. But couldn't that just be a coincidence?

No, Wolf says, it's not. "It's like a dance that you've learned. You dance it over and over again, of course."

Read more:Unbearable: Living with a narcissist 

Love is (also) a decision

The good news is that we can still learn new dance steps as adults. "But," Wolf warns, "you have to face your fear of commitment."

At first, this means nothing more than: endure.

To not run away. To resist the impulse to escape.

Because: "Love, as a state of emergency, cannot last."

Whoever lives according to this maxim, whether or not they know they're doing it, remains on the run for the rest of his or her life. That, of course, is one possibility.

"The question is, do I want to stay true to this maxim?" Wolf asks. "Or do I want to keep him or her?" If so, she says, you have to reconsider what your idea of love really is.

So, first of all, Lena has to decide whether she wants to give this man a chance — without a dopamine overdose rushing through her blood.

Could be worth a try.

And then, if he really isn't a fit after all, she can always leave.