
Proposed in December 1998, the merger has turned Aetna into a managed care powerhouse providing coverage for about one in 11 Americans and having contracts with some 400,000 physicians, more than half the national total. This concentration of economic power, opponents charge, will substitute profit-driven "minimally acceptable clinical guidelines" for treatment plans determined by physicians operating in their patients' best interests. Mental Health Threatened by Aetna/Prudential Merger