Schwarz has no doubt that A.D.H.D. is a valid clinical entity that causes real suffering and deserves real treatment, as he makes clear in the first two sentences of the book: “Attention deficit hyperactivity is real. Don’t let anyone tell you otherwise.” But he believes that those who are disabled by the condition deserve a wider range of treatment options than an endless litany of stimulants with chirpy names like Vyvanse and Concerta.

Disorders of attention were once thought to be relatively rare by experts, affecting only an estimated 3 percent of preadolescent children. But kids and teenagers are now diagnosed so routinely that getting a prescription for Ritalin or Adderall has practically become a standard rite of passage, particularly in the United States. And the diagnosis isn’t just for ­children anymore: Its ever-expanding boundaries now encompass allegedly hyperkinetic infants and the distractible elderly. What’s really going on?

Influential patient-advocacy groups insist that only now is the true prevalence of A.D.H.D. finally being recognized after being drastically underestimated — akin to the spike in autism diagnoses once the narrowly defined condition was broadened into a spectrum in the 1990s. But Schwarz makes a convincing case that the radical expansion and promotion of A.D.H.D. has resulted in the label being applied in ways that are far beyond the needs of a historically underserved community, while nonpharmaceutical methods of treatment like cognitive behavioral therapy (which have been proved to complement the effectiveness of medication) are overlooked.

While other books have probed the historical roots of America’s love affair with amphetamines — notably Nicolas Rasmussen’s “On Speed,” published in 2008 — “ADHD Nation” focuses on an unholy alliance between drugmakers, academic psychiatrists, policy makers and celebrity shills like Glenn Beck that Schwarz brands the “A.D.H.D. industrial complex.” The insidious genius of this alliance, he points out, was selling the disorder rather than the drugs, in the guise of promoting A.D.H.D. “awareness.” By bankrolling studies, cultivating mutually beneficial relationships with psychopharmacologists at prestigious universities like Harvard and laundering its marketing messages through trusted agencies like the World Health Organization, the pharmaceutical industry created what Schwarz aptly terms “a self-affirming circle of science, one that quashed all dissent.”

In a narrative that unfolds with the momentum of a thriller, he depicts pediatricians’ waiting rooms snowed under with pharma-funded brochures, parents clamoring to turn their allegedly underachieving children into academic superstars and kids showered with pills whose long-term effects on the developing brain (particularly when taken in combination) are still barely understood. In one especially harrowing section of the book, Schwarz traces the Icarus-like trajectory of Richard Fee, an aspiring medical student who fakes the symptoms of A.D.H.D. to get access to drugs that will help him cope with academic pressure. When he eventually descends into amphetamine psychosis, his father tells his doctor that if he doesn’t stop furnishing his son with Adderall, he’ll die. Two weeks after burning through his supply, Fee hanged himself in a closet.

“ADHD Nation” should be required reading for those who seek to understand how a field that once aimed to ameliorate the behavioral problems of children in a broad therapeutic context abdicated its mission to the stockholders of corporations like Shire and Lilly. Schwarz is sounding an alarm for a fire that looks nowhere near abating.