As a mental health profession, art therapy is employed in many clinical and other settings with diverse populations; however is not often seen as a valid form of therapy. Art therapy can also be found in non-clinical settings, as well as in art studios and in creativity development workshops. Closely related in practice to marriage and family therapists and mental health counselors, U. S. art therapists are licensed under various titles, depending upon their individual qualifications and the type of licenses available in a given state. Art therapists may hold licenses as art therapists, creative arts therapists, marriage and family therapists, counselors of various types, psychologists, nurse practitioners, social workers, occupational therapists, or rehabilitation therapists. Art therapists may have received advanced degrees in art therapy or in a related field such as psychology in which case they would have to obtain post-master's or post-doctorate certification as an art therapist. Art therapists work with populations of all ages and with a wide variety of disorders and diseases. Art therapists provide services to children, adolescents, and adults, whether as individuals, couples, families, or groups.