Editor’s note: due to the sensitivity of this subject, the couple’s names have been changed. Moreover, during this decision-making process, we highly recommend professional counseling before any decision is made.

Ron and Barb have been married for 37 years, but the last 17 haven’t been easy. And, like many, they ride it solely because of their kids. Now that the kids are grown, Barb is deciding whether or not to stay in the marriage. Ron suggests counseling since he doesn’t want to lose her.

During one session, Ron described an incident from the night before in which they agreed to watch a DVD together before bed. While Barb was setting it up, Ron checked on the Cincinnati Reds’ score. He explained to me that he got engrossed and didn’t return for a half an hour. When he came back to the room he proceeded to tell her about the "fascinating" entertainment during the seventh inning stretch.

Barb interrupted with, "I wish you’d find me 'fascinating.'" She turned to me and said, "He can’t turn the TV off even for a few minutes for me."

"You know my job is stressful," Ron replied. "I use TV as a diversion."

"I wish I were that diversion for you," Barb explained. "But I’m not. I’ve never been, and I don’t think I ever will be. I might as well not be here."

Now, whether you’ve been married for 30-plus years or just a few, how do you decide whether to stay in your marriage or go? For some people, they just know they have to leave. For many though, it’s not clear. They’re entangled by having to consider too many extenuating factors: the logistics of separation and starting over, finances, your children’s reactions, reactions from your parents and siblings, and, of course, society’s subtle prejudice against single women (if you are the wife in this case) and the discomfort of joining that group and starting to date.

Think about what brings couples together. Having similar interests, values and lifestyles may be important. Sometimes it’s chemistry, sometimes a spiritual connection or a friendship that grows into love. Every year you spend in a marriage, this question adjusts to what keeps couples together.

"We went together all though high school and college," says Barb. "We had a lot of fun together, but we were so young. I’ve grown up since then."

"As far as I’m concerned, nothing has changed," insists Ron, "I loved you then and I still love you. I’m the same as I’ve always been. So I don’t understand what the problem is."

"That’s part of the problem,” cries Barb. "You haven’t changed at all, but I have. I’m 40 pounds heavier and a whole lot smarter than I was then. I raised our three kids, worked my way up from cashier to supervisor to manager of the shoe store. I’ve taken courses on classical music and ballet and joined a book club. I’m not content with carrying on as usual. I want more out of life than what we have together. I want to be with someone who is interested in the same things… someone who is interested in growing in his own personal life. And, I want to be with someone who is interested in me."

When wives have long made up their mind about leaving because their husbands won't change or don't seem to listen, marriage therapist and author, Michele Weiner-Davis, calls this the "walk-away wife syndrome." Watch her short video, click here.

Barb stops, as if searching for another thought. "I’m not mad at you, Ron. I’m sad. Sad that we’ve grown so far apart and haven’t been able to bridge our differences. A part of me will always love you, but I need to leave."

I ask her to consider what I call the "Crystal Ball" question: "If you could look into a crystal ball and see that you will never meet anyone else who offers you more than Ron, what would you do?"

Without hesitation, Barb replies, "Even if I never meet anyone else, I need to lead a life that fits who I am now."

Barb has been on her way out for a while. She has been growing and evolving from who she was back in high school, while Ron is content being the same as he always was. This is not a value judgment but a basic difference in approaches to living. And while it works for Ron, it doesn’t for Barb.

Other women in the same position as Barb, after grappling with her needs, come to a different conclusion. The problem is not when a woman becomes clear to stay or to go, the real problem is when that can’t find a way to make that decision. Here are three exercises to expand your thinking around the decision of whether to stay or go.

1. Crystal Ball Method: Pretend you could look into a crystal ball and see that you would never meet anyone who offered you more than what you currently have. Knowing that, would you still want to leave? Is what you aren’t getting worse than not having your spouse at all?

2. Lists: Make a list of all the things that you value and admire about your spouse. Make a list of all the things you really don’t like/can’t stand about your spouse. (Assume this list will be longer; even in good marriages, it usually is.) Now, of the "Don’t Like" list, check those you could not tolerate living with. On the "Value" list, check those you would miss horribly. There is no easy answer, but this exercise might help clarify what’s most important for you, what you can’t live without.

3.Odd Day/Even Day: On odd numbered days (of the calendar), spend the entire day thinking your decision is made and you are going to stay. No matter how bad things may be, how much your spouse upsets or hurts you, experience it through the lens of your remaining in the marriage. On even days do the opposite. No matter how wonderful your spouse is, imagine you are assured of leaving. The purpose of this exercise is to stop you from going back and forth. Stay with one side of your ambivalence the entire day. The next day, take the opposite side. Do this for a week and you may be a bit clearer on what you need to do.

Dr. Karen Gail Lewis is a marriage and family therapist (39 years) and author of numerous relationship books: on enhancing marriage, on being single, on improving adult sibling relationships, and on strengthening friendships. Her most recent book is "Why Don’t You Understand? A Gender Relationship Dictionary.com" (GenderDictionary.com). She also runs Unique Retreats for Women Ready for Change. She can be contacted at DrKGL@DrKarenGailLewis.com.