DSM-IV-TR IN CONTEXT: AN EVOLVING DIAGNOSTIC SYSTEM

Psychiatric diagnostic classification serves a variety of clinical and other purposes. Diagnosis marks the borders between mental disorders and nondisorders (such as normal personality variations and stressful life problems) and between one type of disorder and another.¹ Diagnostic schemata have practical implications for helping clinicians to conceptualize psychiatric issues, to communicate with patients and other clinicians, and, ideally, to make prognostic predictions and to plan effective treatments.^2,3 A useful diagnostic system also enables psychiatric research to flourish. It permits valid and reliable classification of patients in clinical research settings and defines practical human problems that may inspire and benefit from basic research efforts. Recorded efforts to document, describe, and classify mental illness go back thousands of years; they include attempts to group diseases by cross-sectional phenomenology, by theories of causation, and, later, by clinical course.⁴

In the United States, the diagnostic system in widest current use is the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR).⁵ The DSM has been increasingly disseminated internationally. The World Health Organization’s International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10),⁶ has also been in wide use in other countries for classifying psychiatric disorders. While the ICD-10 correlates more closely with DSM-IV-TR, the previous version, International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM),⁷ is still used in the United States for coding purposes within medical billing systems for both psychiatric and nonpsychiatric medical disorders.⁴

The DSM-IV-TR represents the latest in an ongoing process of change in our psychiatric diagnostic system, with the next major revision, DSM-V, expected to be released in 2010 or thereafter.⁸ While the original Diagnostic and Statistical Manual: Mental Disorders was published in 1952,⁹ the transition from the second edition (DSM-II)¹⁰ to the third edition (DSM-III)¹¹ represented a particular change in emphasis. Psychodynamic formulations were no longer intrinsic to diagnostic categorization, and the DSM-III was to be considered atheoretical and descriptive in orientation, using a multiaxial system. As subsequent revisions were made,^5,12,13 there were increasing efforts to ensure diagnostic reliability and validity, to incorporate research findings, and to gather new information via field trials.^3,14–17

THE MULTIAXIAL FORMAT OF DSM-IV-TR

The DSM-IV-TR uses a system of multiaxial assessment to promote evaluation and description of multiple kinds of information (Table 17-1). The multiaxial format succinctly organizes problems that will be both highly relevant and subject to change in the course of treatment. An illustration of one way that clinical material might be recorded in the DSM-IV-TR multiaxial format is provided in Box 17-1, with an example of a 28-year-old woman undergoing psychiatric evaluation. This multiaxial assessment asserts that this patient currently has certain affective, characterological, medical, relational, and environmental difficulties that are substantially impairing function. While the texture of this woman’s individual life story may emerge more clearly from the narrative description, constructing and reviewing the five axes provides a structure that may help the clinician begin to consider medications, psychotherapies, and psychosocial or systemic interventions that could be helpful. Nonetheless, it is up to the psychiatrist in his or her clinical interactions to maintain curiosity about how the problems on each axis are constituted and relate to the others for this patient—how they developed, what meaning may be attached to the problems and their treatment, and how they may be amenable or resistant to change.

Table 17-1 The Five Axes of Diagnosis

Axis I

Axis I contains what the DSM-IV-TR labels “Clinical Disorders”: all psychiatric disorders included in the DSM except for the personality disorders and mental retardation, which are recorded on Axis II (Box 17-2). In addition, Axis I is the location to record “Other Conditions That May Be a Focus of Clinical Attention,” which includes medication side effects and a variety of social and relational problems (Box 17-3). All Axis I diagnoses that are relevant to care should be listed in order of clinical concern, with the most important diagnosis listed first.

BOX 17-2 Axis I: Clinical Disorders

Learning, Motor Skills, and Communication Disorders

Pervasive Developmental Disorders

Attention-Deficit and Disruptive Behavior Disorders

Feeding and Eating Disorders of Infancy or Early Childhood

Tic Disorders

Elimination Disorders

Other Disorders of Infancy, Childhood, or Adolescence

Delirium, Dementia, Amnestic, and Other Cognitive Disorders

Mental Disorders due to a General Medical Condition

Substance-Related Disorders

Schizophrenia and Other Psychotic Disorders

Mood Disorders

Anxiety Disorders

Somatoform Disorders

Factitious Disorders

Dissociative Disorders

Sexual and Gender Identity Disorders

Eating Disorders

Sleep Disorders

Impulse-Control Disorders

Adjustment Disorders

BOX 17-3 Axis I: Other Conditions That May Be a Focus of Clinical Attention

Psychological Factor Affecting Medical Condition

Medication-Induced Movement Disorders and Adverse Effects

Relational Problems

Problems Related to Abuse or Neglect

Treatment Noncompliance

Malingering

Antisocial Behavior (not related to a mental disorder)

Age-Related Cognitive Decline

Bereavement

Academic or Occupational Problem

Identity, Religious/Spiritual, Acculturation, or Phase-of-Life Problem

Various algorithms are available to help maneuver through the DSM, including those in Appendix A of the DSM-IV-TR, “Decision Trees for Differential Diagnosis.” An example for the anxiety disorders is shown in Figure 17-1; others are delineated elsewhere in this textbook. When making the determination of which DSM-IV-TR Axis I diagnoses best fit a particular patient, it is important to attend to which diagnoses are hierarchical and mutually exclusive and which may be co-morbid/co-existing in an individual patient at the same time. For example, a patient may have a long-standing specific phobia of heights, develop obsessive-compulsive disorder (OCD) in adolescence, and then develop post-traumatic stress disorder (PTSD) following an injury in adulthood, resulting in three co-morbid anxiety disorders at the time of presentation at age 45. On the other hand, the criteria for adjustment disorder clearly state that before assigning this diagnosis, the clinician must determine that the symptoms do not fulfill criteria for another Axis I disorder and are not related to an exacerbation of another Axis I or II disorder. Likewise, a nonpsychiatric medical or substance-induced etiology must typically be ruled out to the clinician’s clinical satisfaction before any other Axis I disorder can be diagnosed.

Figure 17-1 Anxiety disorders algorithm. This algorithm demonstrates that some diagnoses are hierarchical and mutually exclusive, whereas others may be co-morbid in an individual patient.

Most sections of the DSM also include “Not Otherwise Specified (NOS)” diagnoses, such as alcohol-related disorder NOS, dissociative disorder NOS, or eating disorder NOS. When used alone or in combination, these may be used to describe disorders that, although clinically significant, do not fit neatly into the major diagnostic categories, or where more data are required before a more precise diagnosis can be assigned. When applicable, diagnosis deferred, no diagnosis, or unspecified mental disorder (nonpsychotic) could be recorded on Axis I. Another option to signal diagnostic uncertainty is to mark a diagnosis as provisional, meaning that the selected diagnosis is expected to emerge over time or with new information. An example of how Axis I diagnoses may evolve in the setting of clinical uncertainty and change is shown in Box 17-4.

BOX 17-4 Axis I: Diagnostic Evolution over Time

You evaluate a 6-year-old child who is extremely impulsive, talkative, hyperkinetic, and distractible. While this has created significant behavioral and interpersonal difficulties, his parents do not describe him as particularly irritable, aggressive, or euphoric. You plan to treat him initially as if he has attention-deficit/hyperactivity disorder (ADHD), but are quite concerned about his strong family history of mania and will be watching closely for the possibility of bipolar disorder as a revised or additional diagnosis. You report Axis I as follows:

Axis I: Attention-Deficit/Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type (Provisional) 314.01

A few visits later, although the boy has not yet started the stimulant medication you have been discussing with his parents, you note that his mood is substantially more irritable than you have previously seen. He starts screaming and throws several metal toy trains at his mother’s head after she says they cannot go to the playground when the visit is over. His parents say that this is not at all unusual for him, and attribute it to the chocolate candies he was eating in the car ride to your office. You revise Axis I as follows:

Axis I: Mood Disorder NOS 296.9

Attention-Deficit/Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type (Provisional) 314.01

Or, depending on your experience of the interaction and clinical judgment (was the child already irritable before his mother’s question about the playground? Did his mother’s verbal and nonverbal response feel harsh and devaluing or like skillful limit setting? Could the chocolate really be contributory?), you might revise Axis I in this way:

Axis I: Attention-Deficit/Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type (Provisional) 314.01

Parent-Child Relational Problem V61.20

A few months later, after you have been working closely with the family, you may have a fuller view of the clinical scenario, new treatment recommendations (including a mood stabilizer and parent guidance work), and a new Axis I that reflects the shift in your understanding. The boy’s mood problem is clearly on the bipolar spectrum, and his parents’ characteristic responses to his tantrums often prolong them. And, although you are now less sure that you feel comfortable prescribing a stimulant, for fear of exacerbating his mood disorder, diagnostically you are more certain that the boy has ADHD symptoms that persist even when he is in a relatively stable mood.

Axis I: Bipolar Disorder, NOS 296.80

Parent-Child Relational Problem V61.20

Attention-Deficit/Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type 314.01

Specifiers may also be added to Axis I diagnoses to provide additional information about the clinical course, features, and severity. Current severity can be indicated with specifiers (i.e., mild, moderate, or severe). When symptoms have substantially improved, the following specifiers may be used: in partial remission, in full remission, or prior history. While guidance is included in the DSM-IV-TR about the definition of these specifiers for some conditions (e.g., conduct disorder, substance dependence, and manic episode), the psychiatrist may apply them to other disorders using his or her clinical judgment. Some disorders have their own specifiers listed in the DSM-IV-TR, such as “with delayed onset” for PTSD. Others have various mutually exclusive subtypes, such as blood-injection-injury type or natural environment type for specific phobia (see Figure 17-1). In some cases, as with mood disorders, the DSM-IV-TR provides instructions for representing specifiers or subtypes via the fifth digit of the ICD-9-CM numerical diagnostic code.