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.

What is a good way to find a therapist?