Art Therapy is:

the therapeutic use of art making within a professional relationship, by people who experience illness, trauma, or challenges in living, and by people who seek personal development. Through creating art and reflecting on the art product and processes, people can increase awareness of self and others; cope with symptoms, stress, and traumatic experiences; enhance cognitive abilities; and enjoy the life-affirming pleasures of art-making.

Art Therapists are: 

professionals trained in both art and therapy. They are knowledgeable in the areas of human development, psychological theories, clinical practice and guidelines, spiritual, multicultural and artistic traditions, and the healing potential of art. Art Therapists use art in treatment, assessment and research, and provide consultations to allied professionals and family members.