Earlier this week, Senator Charles Grassley announced a probe into the nation’s largest advocacy group for people with mental illness, the National Alliance for Mental Illness, asking the nonprofit group to disclose the funding it has received in recent years from the drug industry. The fact that NAMI is heavily dependent on drug company money is old news, but Grassley’s investigation, first reported in Bloomberg News, may shed a welcome spotlight on an lobbying organization that masquerades as grassroots.

In Side Effects, I reveal that drug company contributions have always been a substantial portion of NAMI’s revenues. I also tell the story of how Jim McNulty, president of NAMI from 2002 to 2004, failed to disclose the fact that he was being paid thousands of dollars from drug makers for promoting their products to NAMI members and others at various speaking engagements. In a particularly intriguing twist, McNulty laundered this drug company money through a state chapter of NAMI.

This is how the scheme worked, according to McNulty himself and others in the know. He would be paid thousands of dollars to speak about the benefits of various antidepressants — McNulty himself suffered from depression — and rather than pay him directly, companies such as Eli Lilly, the maker of Prozac, Pfizer, the maker of Zoloft, and GlaxoSmithKline, which made Paxil, would give his speaking fees to the Rhode Island chapter of NAMI, which would then cut McNulty a check. When I asked McNulty why he was paid this way, he said, “Paperwork. It was simpler that way.”

McNulty, of course, never disclosed these conflicts to his constituents or to the NIH (which appointed him to sit on influential advisory boards that rendered opinions about the safety and efficacy of the drugs he was being paid to promote).

NAMI continues to receive hefty contributions from the drug industry but it no longer reveals the specific donors in its annual report, published online. So Grassley’s team has asked the organization to disclose the specifics of its funding so that people with mental illness and their families can see for themselves how conflicted this advocacy group is. At FDA hearings over the years held to examine the safety and effectiveness of antidepressants like Prozac and Paxil, NAMI was always quick to come to the defense of these drugs. And NAMI opposed the black box warnings the FDA required drug makers to put on the labels of antidepressants in 2004 about their increased risk of suicidal thoughts and behaviors. Now that Grassley’s team is looking into NAMI’s books, perhaps the group’s members — people with mental illness and their families — will cast a more skeptical eye on its credibility.