Mr. Fitzpatrick said Mr. Grassley’s scrutiny, which he described as understandable given the attention paid to potential conflicts of interest in medicine, had led his organization to begin posting on its Web site the names of companies that donate $5,000 or more. And he predicted that other patient and disease advocacy groups would be prodded by Mr. Grassley’s investigation to do the same.

“Everyone I talk to wants to have more balanced fund-raising,” Mr. Fitzpatrick said.

In a statement, Mr. Grassley praised the alliance for its disclosures. “It’d be good for the system for other patient groups to do what NAMI has done,” he said.

Mr. Grassley’s scrutiny has been unnerving for patient and disease advocacy groups, which are often filled with sincere people who are either afflicted with serious illnesses themselves or have family members who have been affected. Many join the groups in the hope of making sense of their misfortune by helping to find a cure or raising awareness of a disease’s risks and frequency.

Drug makers are natural allies in these pursuits since cures may come out of corporate laboratories and the industry’s money can help finance public service campaigns and fund-raising dinners. But industry critics have long derided some patient organizations as little more than front groups devoted to lobbying on issues that affect industry profits, and few have come under more scrutiny for industry ties than the mental health alliance.

For years, the alliance has fought states’ legislative efforts to limit doctors’ freedom to prescribe drugs, no matter how expensive, to treat mental illness in patients who rely on government health care programs like Medicaid. Some of these medicines routinely top the list of the most expensive drugs that states buy for their poorest patients.

Mr. Fitzpatrick defended these lobbying efforts, saying they were just one of many the organization routinely undertook.

The close ties between the alliance and drug makers were on stark display last week, when the organization held its annual gala at the Andrew W. Mellon Auditorium on Constitution Avenue in Washington. Tickets were $300 each. Before a dinner of roasted red bell pepper soup, beef tenderloin and tilapia, Dr. Stephen H. Feinstein, president of the alliance’s board, thanked Bristol-Myers Squibb, the pharmaceutical company.