The Psychiatrist's Manual, Analyzed - NYTimes.com Re "Shortcomings of a Psychiatric Bible" (editorial, May 12): It is almost amusing to watch as the debates over the new Diagnostic and Statistical Manual of Mental Disorders emerge. The D.S.M. is and has always been just a tool, an instrument. And you know what they say: it is the poor musician who blames his instrument. The depth and breadth of the psychiatric literature is huge, and it is the totality of this literature, not just the D.S.M., that guides clinicians in the diagnosis and treatment of psychiatric conditions. As we struggle every day to care for and bring peace of mind to our patients, we in the trenches draw from many sources. These include evidenced-based medicine, double-blind placebo-controlled research studies, anecdotal reports in peer-reviewed journals, and clinical experience gleaned from our own practices and the practices of our colleagues. We also draw from intuition, and, yes, even from imperfect lists of clinical criteria created by the committees of the American Psychiatric Association and compiled into diagnostic and statistical manuals. TODD ROSEN Bloomfield Hills, Mich., May 12, 2013 The writer, a fellow of the American Psychiatric Association, has been in clinical practice for more than 30 years. Hallelujah! Dr. Sally L. Satel hits a home run with "Why the Fuss Over the D.S.M.-5?" Sunday Review, May 12. As a psychiatrist who specializes in talk therapy, I spend most of my administrative time justifying this to insurance companies. I fear that all the new diagnostic manual will do for me is worsen this. I disagree, though, with Dr. Satel that it won't affect me. It already has. With the new coding changes (affecting how psychiatrists bill treatment) that took place on Jan. 1 and the new D.S.M. codes (coming later this month), I will have to spend even more time fighting insurance companies for treatment for my patients. For the first time in my 15 years of practice, I have insurance companies flat out denying treatment. With every change come more opportunities for them (and others) to find loopholes. Sigh. Maybe with more articles like this, we can empower consumers and patients to fight back. The search for genes and biological markers in psychiatric illnesses is essential ("Psychiatry's New Guide Falls Short, Experts Say," news article, May 7), but to expect "the biological underpinnings of disorders" to solve the inevitable problems of any diagnostic system is both unrealistic and unscientific. For example, schizophrenia, like most chronic physical illnesses, has multiple causes: genes, infection during pregnancy, lack of oxygen at birth, abuse or neglect in early life, marijuana in adolescence, discrimination and acculturation difficulties, among many others. The biological findings may be consequences of the causes and not "underpinnings" and may not be specific for schizophrenia and are not yet useful for diagnosis. Nature does not come in defined categories, but for practical, clinical, communication, administrative and research purposes, we need them with their somewhat arbitrary cutoffs from other conditions and from "normal." D.S.M.-5 is as good and as scientific as we can get at the moment. The writer is a psychiatrist at Bronx Psychiatric Center and a member of the Assembly of the American Psychiatric Association, which voted to approve D.S.M.-5.