In a surprising move, the US government institute responsible for overseeing mental health research is distancing itself from the Diagnostic and Statistical Manual of Mental Disorders, or DSM. The DSM has, for several decades, been perceived as the "bible" that delegates how psychiatric illnesses are defined, diagnosed, and treated.

The National Institute of Mental Health (NIMH) — which funds more research into mental illness than any other agency in the world — this week announced a plan to re-orient its investigations "away from DSM categories." The move comes mere weeks before the publication of the DSM-5, an update to the manual that's been mired in controversy because of several contentious changes to existing diagnostic criteria.

"Patients with mental disorders deserve better."

"The strength of each of the editions of DSM has been 'reliability' — each edition has ensured that clinicians use the same terms in the same ways," reads the announcement from NIMH director Thomas Insel. "The weakness is its lack of validity." In particular, Insel notes, diagnostic criteria in the DSM are based on symptom clusters, rather than any objective measures. As experts continue to broaden their understanding of genetics and cognitive science, for instance, Insel anticipates the possibility of more rigorous diagnoses. "Patients with mental disorders deserve better," he added.

To promote those rigorous diagnoses, the NIMH will now focus on funding research that digs into these underlying biological mechanisms. The eventual goal, Insel writes, is to collect "the genetic, imaging, physiologic, and cognitive data to see how all the data — not just the symptoms — cluster and how these clusters relate to treatment response."

Of course, it'll be decades before these new research programs inform diagnoses or yield new treatments for mental disorders. But for now, the move — and its timing — suggests that the "bible" of mental health might not merit that moniker for much longer.