Adamson continued to work alone with hundreds of people in his art studios after Dax left until his retirement in 1981. He developed a ‘non-interventionalist’ approach to facilitate the act of creation: how not to influence, distort or impinge on self-expression was the artist’s or therapist’s primary concern.  His work exploring the possibilities of art as therapy was hugely influential.

From the 1940s he was working with the pioneers of art therapy towards establishing Art Therapy as a profession.  In 1964 he was a founder member of the British Association of Art Therapists and briefly its first Chair.  In the early 1970s he was head of the first British art therapy training course at St. Alban’s School of Art, now part of Hereford University.

Though he was not at home with art therapy’s move towards psychoanalysis in the 1970s, his work at the Netherne art studio, the Adamson Collection, his galleries at Netherne and Ashton Wold and his book, ‘Art as Healing’, are key documents for British Art Therapy.

Adamson believed passionately in exhibiting the work made in the studio as the Adamson Collection.  He saw this as educating the public about the creativity and humanity of those they had excluded in the asylums.