Couples counseling, marriage therapist Pat Love says, is "like assembling an airplane in flight." Highly stressful. Highly volatile. Potentially explosive.

So you want a skilled technician in control. But not all counselors are trained to navigate the rough winds of a relationship in distress. And they can do more harm than good, some experts say.

"Unfortunately, many therapists have not been trained to step out of the who's-to-blame dynamic," said Diane Gehart, professor of marriage and family therapy at California State University at Northridge.

While any number of social workers, psychologists and other counseling professionals can perform couples therapy — and many do it well — that doesn't necessarily mean they've had much experience with it or that they've gone through the specialized course work required of licensed marriage and family therapists.

And when a therapist accustomed to treating individuals brings an individualistic approach to a couples session, it can backfire, Gehart said.

Unlike traditional psychodynamic therapy for individuals, the most effective couples therapy doesn't plumb the unconscious or delve into the past or seek to identify the psychopathologies causing people to behave in destructive ways, Gehart said.

Rather, couples therapy works best when it focuses on the systemic interactions between partners, she said — that is, how the relationship dynamics are perpetuating patterns that are driving them apart and what positive steps each person can take to change them.

"You learn to treat the system, not the symptom," said Love, an Austin, Texas-based author of several relationship books. "If you don't pay attention to the system, one person will feel betrayed, left out, reactive and not want to come back to therapy."

So in the classic case of the stoic husband and emotional wife, good couples therapists might identify how his indifference is driving her panic, and vice versa, so both can make changes and neither shoulders all the blame, Gehart said. What they don't do is finger the man's inability to express his feelings as the central problem — a sure way to drive away a guy who probably didn't want to be there in the first place.

Love said people often come to therapy in hopes of getting the therapist to agree that their partner is, in fact, a useless lump or a horrid nag. And it's hard not to get sucked into their worldview.

Before she became trained as a couples therapist, Love said, "I thought a couple came in, and they would tell me their story, and I would say, you're right, you're wrong, and I would break the tie."

But siding with one partner or even the perception of siding with one partner hurts the cause.

The real client in couples counseling is the relationship, Love said. And it needs a calm and cogent arbiter whom both partners trust to direct the session when temperatures in the room rise.

"Can you cut people off? Can you intervene? Can you redirect? Can you draw out emotions? Can you build a bridge between the two people?" Love said.

Bill Doherty, director of the Minnesota Couples on the Brink Project at the University of Minnesota, has been writing about bad couples therapy for years. One of the most important questions people should ask when seeking a therapist, he said, is how much of their practice is devoted to couples. Look for at least 30 percent.

Among the missteps a well-meaning but inexperienced counselor can take, Doherty said:

-- Appearing to side with one partner over the other.

-- Allowing hot conflict, including letting partners interrupt each other and blame or criticize each other.

-- Offering bromides about good communication but little else.

-- Failing to give homework that each partner can work on for the next session.

-- Performing a cost-benefit analysis on whether the relationship is worth saving.

-- Advising partners that they may be better off split.

Doherty advocates against couples therapy that takes a "values-neutral" approach that treats marriage and divorce as equally viable options or the "me"-oriented perspective that views relationships as platforms for people to be happy.

That's not to say people should stay miserable. But Doherty notes that there's a lot of psychological research showing the pursuit of happiness is itself self-defeating.

"Happiness is a byproduct of a life well-lived — of good relationships, of making a difference in the world," Doherty said.

Doherty didn't always practice what he now preaches. At the start of his career, he said, he took an individualistic approach to couples therapy, and if one partner didn't want to save the marriage, he didn't see how it was worth saving. About 30 percent of couples who seek counseling are these "mixed agenda" couples in which one person is "leaning out."

But while not all marriages can or should be salvaged, it's not the counselor's role to decide.

"I'm the last person to give up; I'm not the first person to give up," Doherty said.

People should be able to tell early on if the therapy is helpful. Within the first couple of sessions, each partner should feel that the therapist understands his or her point of view and is actively structuring the sessions, Doherty said. The relationship should be improving in five to eight sessions.

When done right, about 70 percent of couples therapy cases show positive change, according to a study last year in the Journal of Marital and Family Therapy.

When done wrong, it can make things worse, Gehart said.

In particular, going alone to individual counseling for marital problems increases the chance of divorce, research shows. That's because the client is telling only one side of the story to an empathetic therapist, so it becomes a gripe session about how unhappy the person is in the relationship and the absent partner starts to look like even more of a monster, exacerbating the couple's polarization, Gehart said.

That's not to say it's never appropriate to see an individual therapist for relationship problems. For example, if one partner's depression or commitment issues caused the discord, that person might benefit from individual counseling to work on those personal issues (though if the marital problems came before the depression, couples therapy is the way to go), Gehart said.

Still, it can be helpful to bring in the partner for a session or two.

Chuck, 60, who asked that his last name not be published, said poor counseling failed to rescue his marriage when he and his wife of nine years sought help for their unraveling intimacy.