It depends on what you need
A psychologist may or may not practice relationship therapy. Some psychologists just do testing, research, or work in various organizations, such as schools and businesses. The difference between a psychologist and psychiatrist is that a psychiatrist can prescribe medicine because he or she has an M.D. An M.D. can prescribe psychotropic medications but the psychiatrist has more expertise with specific medications in combination with other medications that suit the problem. Many times you can see a psychiatrist to manage ongoing medication and then see a psychologist or marriage and family therapist for personal therapy.
Getting a referral
If you are looking for personal or relationship therapy it is best to get a referral from someone you trust. Even though psychologists, psychiatrists, marriage and family therapists, and licensed social workers are licensed to do psychotherapy, they personally have varying degrees of expertise in this area. Generally speaking, if you need a psychological evaluation which requires testing, a psychologist is the most qualified. Many psychiatrists test also, but their expertise tends to be in the area of medication.
Who do you feel comfortable with?
A psychologist has a PhD whereas a marriage and family therapist, and social worker have a Master’s degree. These degrees however, do not necessarily represent their ability when it comes to individual and relationship therapies. This ability is developed through education but has more to do with their personal development as individuals. In other words, as C.G. Jung described, the therapist, “can help his patient just so far as he himself has gone and not a step further”. Therefore, first decide what you need, then get several referrals, and then inquire into their specialties. If you are looking for personal therapy or relationship therapy, it is best to meet the therapist and then decide who you feel most comfortable with.