The ultimate authority on mental health is a 974-page book called the Diagnostic and Statistical Manual of Mental Disorders (DSM), now in its 5th version.

Mental health professionals have used the DSM for decades as a checklist to diagnosis illnesses. If patients have enough symptoms — such as "grandiose behaviors" or "decreased need for sleep" — for a certain illness, then they can receive a formal diagnosis.

The book is so large and has such sweeping definitions of disorders, however, some claim it has contributed to the over-diagnosis and over-medication of Americans. Indeed, one quarter of American adults currently live with a mental illness, according to the Centers for Disease Control.

In his investigative novel, "The Psychopath Test," author and journalist Jon Ronson explores the history of the DSM.

In one chapter, Ronson interviews Robert Spitzer, the man responsible for the greatest advancement of the DSM in the 70s. When asked if the DSM might portray ordinary behaviors as some sort of psychosis, however, even Spitzer replied: "I don't know."

The first DSM was only 65 pages. The next bulked-up to 134. The version edited by Spitzer, the DSM-III, reached 394 pages. After a few more revisions, today's DSM-5 sits at a whopping 947 pages and includes more than 300 afflictions. More than 400 mental professionals worked for thirteen years to complete the text.

From 1974 to 1980 — the period when the DSM more than doubled in size — Spitzer presided over chaotic editorial meetings in a small conference room at Columbia University. The invited psychiatrists yelled over each other, and no one took minutes, Ronson writes.

The DSM-III's growth came as a reaction to growing skepticism about psychiatry in the U.S., since diagnoses weren't typically based on hard data. The third edition favored German psychiatrist Emil Kraepelin's idea that biology and genetics play a key role in mental illness, an idea still present in modern medicine, according to PsychCentral. Around this time, the DSM would become so essential to mental health practice in America.

Today, psychologists and psychiatrists still need the DSM to assign names and symptoms to their patients' issues and to ease communication when publishing papers and giving talks. Its use goes far beyond the doctor's office too. Insurance companies require DSM diagnoses for reimbursement. Court systems, social-services agencies, schools, prisons, and many other government groups also use the illnesses defined in the book to help determine who requires special services, The New Yorker's Alix Spiegel writes.



Despite making diagnosis easier, expanding the DSM with new illnesses and broader criteria for others could have also contributed to the U.S.' over-medication. More than one in ten Americans take medication for depression, only one of the numerous disorders present in the DSM. And the rate has grown more than 400% since the 80s, coincidentally when the DSM became the mental health professionals' bible.

"[The DSM-III] was truly a revolution in psychiatry, and a gold rush for drug companies, who suddenly had hundreds of new disorders they could invent medications for, millions of new patients they could treat," Ronson writes.

Most notably, Ronson speculates the DSM-III fueled drastic over-diagnosis of childhood bipolar disorder, a "mental illness" that most psychiatrists outside the U.S. don't even believe exists.

Bipolar disorder is "an illness that emerges from late adolescence. It is very, very unlikely indeed that you'll find it in children under seven years of age," Ian Goodyer, a professor of neurology at Cambridge University, told Ronson.

Based on the criteria in the DSM-4, around 7% of children could be diagnosed with bipolar disorder, according to the National Alliance on Mental Illness. DSM-5 addresses these concerns, however, with the addition of Disruptive Mood Regulation Disorder, which provides an alternative to bipolar diagnoses for children who have chronic irritability, as well as frequent episodes of temper outbursts several times a week for more than a year, according to Yahoo! Shine.

Ronson's work also questions whether the manual classifies regular mental states as some sort of psychosis. For example, nail-biting could constitute obsessive compulsive disorder. Even if the DSM's creators referred only to severe nail-biting that interfered with daily life or caused harm, some could take the trivial behavior out of context.

Spitzer admitted that these issues could be seen as problematic.

From the "The Psychopath Test":

"Do you ever think about it?" I [Ronson] asked him [Spitzer].

"I guess the answer is I don't really," he said. "Maybe I should. But I don't like the idea of speculating how many of the DSM-III categories are describing normal behavior"

"Why don't you like speculating on that?" I asked him.

"Because then I'd be speculating how much of it was a mistake," he said.

There was another long silence.

"Some of it may be," he said.