Some people put therapy on their list of New Year’s resolutions. But how does a person find the right therapist—and know when the therapy is working?

Nando Pelusi, a psychologist and advisory board member of the National Association of Cognitive-Behavioral Therapists, discussed what contributes to therapy’s success. Most important is the relationship between the client and the therapist, says Dr. Pelusi, who has had a private practice in New York City for 20 years. Some edited excerpts from his interview:

How does somebody know if therapy would be helpful?

Dr. Pelusi: If you feel like you’re blocking yourself, defeating yourself, feeling emotionally unstable, avoidant, or pessimistic, then you’d benefit. If you’re avoiding something you want to do or doing something you don’t want to do. Say you are attracted to someone but run the other way when you see them. Or you decide to cut down on alcohol but you keep drinking.

More on this...

What is a good way to find a therapist?

I recommend the therapy directory on the website of Psychology Today. You can look up location, type of therapy, the therapist’s experience. Narrow your list down to half a dozen candidates and call them. Some will give a free phone consultation. When people call me, I answer questions on how I work and tell them my approach. If there is a good fit, we will set a meeting up. You can also get recommendations by word of mouth.

Click for more from the Wall Street Journal.