A majority of young doctors feel pessimistic about the future of the U.S. healthcare system, with the new healthcare law cited as the main reason, according to a survey released to Reuters on Wednesday. Nearly half of the 500 doctors surveyed think the Affordable Care Act will have a negative effect on their practices, compared with 23 percent who think it will be positive. The survey was commissioned by The Physicians Foundation, a non-profit organization that promotes the work of practicing doctors through grants, research and policy impact studies.