Every day at the medical school, patients and control subjects undergo imaging tests, hop on treadmills and swallow medications in the name of advancing knowledge. Some do it to contribute to society and research, some are lured by the payments offered, and some hope to help find a cure and ease a loved one’s suffering or that of future patients.

That last consideration is what motivated Kriste Gill to enroll her newborn twins in a study on early indications of autism. A speech pathologist with a professional interest in the study, Gill also has a 22-year-old brother with autism. “I get to give back to research for a disability that’s very near to us,” she said. For the past two years, Gill’s babies have undergone developmental assessments. The exams are not physically invasive, and Gill has learned much about the twins’ development. And if any signs of autism should surface, she’s confident the research team would flag them and recommend next steps for further evaluation.

A different concern brought Jan Davey into the Kronos Early Estrogen Prevention Study (KEEPS), a study to determine whether early menopausal hormone therapy prevents or delays heart disease. Davey, 61, has a 27-year-old daughter and sees the need for research that may benefit future generations of women. Participants commit to taking hormones or a placebo as well as undergoing periodic lipid profile tests and vaginal ultrasounds for four years. As a clinical research nurse in Cardiovascular Medicine and at Yale Cancer Center, Davey understands the demands and rewards of clinical trials but had never before participated in one. “It’s a very important part of what we do in health care,” she said.

Some participate in hopes of obtaining treatment for a disease from which they or a loved one suffer. Terri Rathbun’s 16-year-old daughter, Molly, has childhood absence epilepsy—short seizures in which the person appears to blank out. Her condition has not responded to medication. To assess Molly’s brain function, she underwent MRI scans while performing cognitive tasks. Her mother is hoping the study will benefit other children; in the meantime, it has helped her recognize how well Molly has coped while living with seizures. According to her mother, Molly hopes that participating in this study “will open up opportunities for other kids so that seizures don’t define their lives.”

For cancer patients Kathy Willie and Geralyn Spollett, a trial for treatment of HER2-positive breast cancer was a chance to receive chemotherapy that might have reduced or eliminated their tumors before surgery. Willie initially didn’t want to undergo chemotherapy, but her decision paid off; during a partial mastectomy her surgeon found no trace of the tumor. Although the treatment didn’t change the course of Spollett’s treatment—she ended up needing a mastectomy as well as chemotherapy and radiation—she believes it was a positive experience. “I felt lucky to be in the trial because of the consultation and support,” said Spollett, who will have follow-up blood work in September.

Social responsibility also motivates patients. Jean O’Brien, 65, and her daughter Stephanie, 32, have X-linked hypophosphatemia (XLH), the most common form of inherited rickets in the United States. They joined in a study designed to define the features of the disease in adults. “It’s a few days out of my life that could change someone else’s life,” said Stephanie, referring to two days of bone scans, X-rays and ultrasounds at Yale-New Haven Hospital. “My generation is writing the textbook on this disease,” said Jean, who hopes the study will benefit her grandson and future grandchildren.

Clinical trials require not only sick but also healthy subjects. One 76-year-old woman participates in the Alzheimer’s Disease Neuro-imaging Initiative even though she is healthy. As part of the three-year study she gets MRI and PET scans every six months so that researchers can compare the mental changes that occur in normal aging, mild cognitive impairment and Alzheimer disease. She hopes that the trial will lead to a cure that will help family members and friends who have the disease.

Because he has a family history of heart disease, 27-year-old Niall McComiskey agreed to a stress test on a treadmill, administration of adenosine to increase his heart rate and a PET scan. McComiskey also said that the $200 he was paid didn’t hurt, and for some people, financial compensation is reward enough. For others, it’s a combination of factors that spur them to participate. One 40-year-old veteran, a recovering alcoholic and addict who suffers from post-traumatic stress disorder, had two reasons for undergoing PET scans as part of a study to measure the levels of neurotransmitters in brain tissue. He wanted to understand the chemical imbalances in his brain; he was also paid about $700 to participate in the study. Thomas O. Carpenter, M.D., professor of pediatrics (endocrinology), offers a $25 grocery card to participants in his nutritional study, which he said is an effective incentive.

Such are the rewards of clinical studies that patients often repeat the experience. Jan Davey, who is participating in the keeps study, has also signed up for three ancillary studies. “We wouldn’t be where we are in health care if we hadn’t been doing clinical research all these years,” she said.