In May of 2013, the American Psychiatric Association will publish the much-anticipated fifth edition of its Diagnostic and Statistical Manual of Mental Disorders – a tome often called the “Bible of psychiatry” because it defines every recognized mental disorder and is used in all facets of the U.S. system of mental health care and psychiatric research. The first edition of this manual appeared just over six decades ago, and periodic revisions since then have evolved into major events with high stakes for patients, researchers, and mental health care providers. Over the years the process of revision has become highly controversial, as more and more disorders have been identified. Is America really suffering from an “epidemic” of mental illnesses?

The Proliferation of Recognized Disorders

The United States has experienced fundamental shifts in how mental disorders are recognized and treated. Rates of mental disorders have skyrocketed, gradually in earlier years and more rapidly lately. From 2002 to 2008, for example, diagnoses of autism rose by 78% and now affect one of every 88 American children. A similar expansion has occurred for common conditions like depression and anxiety. A proliferation of diagnosed disorders brings greater use of prescriptions for psycho-pharmaceutical drugs. Today, more than one in five adult Americans takes at least one of these drugs.

Experts agree that a proliferation of categories has contributed to more diagnoses of mental disorders. Back in 1952, the first edition of the Manual used 130 pages to detail 106 disorders; by 1994, the fourth edition took 886 pages to spell out 297 disorders. Not only have the number of diagnosed disorders grown, but the thresholds for diagnosing a patient have been reduced. Several factors have encouraged the recognition of more disorders with lower thresholds:

• Revisions of the Manual are massive undertakings involving thousands of psychiatrists who work for nearly a decade, so there is pressure to make additions each time.
• Additions happen more readily than subtractions because psychiatrists want to give all patients needed treatments – and now that mental illness is not as stigmatized as it once was, they are less worried about mislabeling a condition.
• More listed disorders mean more patients and new research grants to study each condition.
• Patient advocacy groups often lobby through the media to have particular disorders listed.

Additions to the Manual are also facilitated by the fact that most mental disorders have no sure-fire biological test to indicate their presence. Scientists still have much to learn about the underlying neurological and biological causes of mental disorders, so experts who revise the Manual fall back on defining mental disorders by the symptoms patients report and caregivers interpret. Unlike other medical illnesses, mental disorders are defined by groups of psychiatrists who assess available data – a process inevitably vulnerable to subjective interpretations and adjustments.

Controversial Examples from the Fifth Revision

When they set to work in 2006, the members of the task force doing the fifth edition of the Manual hoped to make dramatic revisions based upon new insights from neurological and genetic research. But they soon discovered that available studies were insufficiently certain or advanced in many areas. As the following examples show, they ended up settling on controversial revisions that expanded diagnoses and loosened criteria.

• In previous editions, individuals experiencing depressive symptoms after the death of a loved one were not eligible to be diagnosed with “major depression.” But now this exclusion has been relaxed. To critics, this furthers the inappropriate redefinition of normal emotional responses to life events as mental illnesses.

• According to the fifth edition, children who are constantly irritable and have explosive outbursts will be eligible for a new diagnosis called “Disruptive Mood Dysregulation Disorder.” The idea is to prevent the overdiagnosis of pediatric bipolar disorder. But critics worry that this added disorder will lead to new drugs and more prescriptions for young children. Between 1993 and 2009, there was a sevenfold increase in the number of doctor’s visits in which antipsychotic medications were prescribed to children under 13 years old.
• Attempts to rein in diagnostic expansion often meet resistance from patients, because a diagnosed illness opens access to services – and can provide an identity for group advocacy. One change in the new edition that has sparked media attention is the elimination of Asperger’s Syndrome as a distinct diagnostic category. This change threatens the self-identification of “Aspies” and raises worries about a loss of special education services.

Implications for the Future of American Health Care

Because the Diagnostic and Statistical Manual of Mental Disorders is so influential, its steadily expanded listings of disorders raise issues of cost and coverage – especially now that the Affordable Care Act of 2010 requires equal treatment for both mental and physical illnesses.

• If revisions of the Manual are pushing an over-expansion in mental disorders, will America have to worry about paying an excessive and unaffordable bill for mental health care?
• The opposite worry is also pertinent. Faced with more and more patients, insurance companies try to save money by encouraging drug treatments instead of intensive therapies. But patients suffering from severe mental illnesses need both kinds of help – and they may not get what they need if minor diagnoses proliferate and we rely on drugs for everything to save money.

As this discussion shows, when addressing the supposed epidemic of mental illness in America, policy makers should be aware that not all disorders are equally severe. By recognizing that some disorders are a matter of definitional proliferation, policy makers can achieve a better understanding of the true nature of mental health and illness in the United States – and make wiser choices about the use of scarce resources to achieve good health care for all.