Several therapy programs in the United States use hug machines, effectively achieving general calming effects among both children and adults with autism. A 1995 study on the efficacy of Grandin's device, conducted by the Center for the Study of Autism, working with Willamette University in Salem, Oregon, involving ten children with autism, found a reduction in tension and anxiety.[5] Other studies, including one by Dr. Margaret Creedon, have yielded similar results. A small pilot study published in the American Journal of Occupational Therapy reported that the machine produced a significant reduction in tension, but only a small decrease in anxiety.[6]
Grandin continued to use her own hug box on a regular basis to provide herself the deep pressure necessary to relieve symptoms of her anxiety. "I concentrate on how gently I can do it," she has said. Grandin has written a paper on her 'hug machine' and the effects of deep pressure stimulation that has been published in the Journal of Child and Adolescent Psychopharmacology