It seemed an ideal marriage, a scientific partnership that would attack mental illness from all sides. Psychiatrists would bring ... their expertise and clinical experience, drug makers would provide their products and the money to run rigorous studies, and patients would get better medications, faster. But now the profession itself is under attack in Congress, accused of allowing this relationship to become too cozy. After a series of stinging investigations of individual doctors' arrangements with drug makers, Senator Charles E. Grassley, Republican of Iowa, is demanding that the American Psychiatric Association, the field's premier professional organization, give an accounting of its financing. I have come to understand that money from the pharmaceutical industry can shape the practices of nonprofit organizations that purport to be independent in their viewpoints and actions," Mr. Grassley said. In 2006 ... the drug industry accounted for about 30 percent of the association's $62.5 million in financing. One of the doctors named by Mr. Grassley is the association's president-elect, Dr. Alan F. Schatzberg of Stanford, whose $4.8 million stock holdings in a drug development company raised the senator's concern. Commercial arrangements are rampant throughout medicine. In the past two decades, drug and device makers have paid tens of thousands of doctors and researchers of all specialties. Worried that this money could taint doctors' research plans or clinical judgment, government agencies, medical journals and universities have been forced to look more closely at deal details.