The DSM-5: A System for Psychiatric Diagnosis

Section I

DSM-5 is divided into three sections. Section I provides a history of the DSM and guidance for its use. Of note, DSM-5 diagnostic criteria are not meant to be rigidly applied to mandate or exclude individuals from treatment when clinical circumstances dictate otherwise. In addition, given that DSM-5 has been created primarily for use in health care and research, it is not intended to be sufficient for making legal determinations. In all settings, clinical judgment must be applied in gathering and interpreting diagnostic information, ensuring the presence of distress or functional impairment, and incorporating all available data into a clinical formulation.

Section II

Section II lists DSM-5 diagnoses and codes, separated into categories of related disorders. Disorders are described beginning with those which have a neurodevelopmental origin early in the life span, and ending with diseases that most often appear late in life. Within the developmental framework, disorders have also been grouped according to current neuro-scientific understanding that links disorders based on shared genetic findings (i.e., between bipolar and psychotic disorders), clinical courses, and patterns of co-morbidity. Variability and changes in presentation that occur through the life span—such as the age-dependent change in hyperactive symptoms that typically occurs in attention-deficit/hyperactivity disorder (ADHD)—are also included for individual disorders under the subheading of “Development and Course.” Gender-related factors that may have an impact on risk, presentation, or clinical course are incorporated throughout Section II as “Gender-related Diagnostic Issues.” These two new sub-sections were added to highlight the importance of development and gender in psychiatric diagnosis.

When determining which diagnoses best fit a particular patient, one must consider which diagnoses are hierarchical and mutually exclusive, and which may be co-morbid/co-existing at the same time. For example, a patient may have a separation anxiety disorder beginning in pre-school, develop impairing social phobia in early adolescence, and then experience a specific phobia of heights following a trip to the Grand Canyon during high school, resulting in three co-morbid anxiety disorders at the time of presentation at age 15. Alternatively, the adjustment disorders exclude other diagnoses, as the clinician must determine that the presenting symptoms do not fulfil criteria for another psychiatric disorder. Likewise, a non-psychiatric medical or substance-induced etiology must typically be ruled out to clinical satisfaction before any other disorder can be diagnosed.

A procedure is needed to describe disorders that, although clinically significant, do not fit neatly into the major diagnostic categories, or where more data are required before assigning a more precise diagnosis. In DSM-IV-TR, “Not Otherwise Specified (NOS)” diagnoses were used for this situation; for example, “eating disorder NOS” could be used for patients who did not meet full criteria for either anorexia nervosa or bulimia nervosa. In DSM-5, NOS diagnoses have been eliminated. Instead, clinicians can use the term “other specified” when wishing to indicate the reason that full diagnostic criteria are not met ( Box 17-1 ). “Unspecified” can be used when a disorder is clearly present, but no specific reason is given for not meeting full criteria. This situation could occur when insufficient historical information is available, as in an emergency evaluation of a patient. The “unspecified” label can be used to broadly indicate the presence of a psychiatric disorder (e.g., unspecified mental disorder), or, when possible, to place a diagnosis within a certain family of disorders (e.g., unspecified bipolar and related disorder) (see Box 17-1 ). Another option to signal diagnostic uncertainty is to mark a diagnosis as provisional, meaning that the selected diagnosis is expected to emerge more clearly over time or with additional information.

Specifiers may also be added to diagnoses to provide additional information about the clinical course, features, and severity. For many diagnoses, current severity can be indicated with specifiers (i.e., mild, moderate, or severe). When symptoms have substantially improved, the specifiers “in partial remission” or “in full remission” are sometimes used. Some disorders have their own specifiers listed in DSM-5, such as “with dissociative fugue” for dissociative amnesia. Others have various mutually-exclusive subtypes, such as blood-injection-injury type or natural environment type for specific phobia. The DSM-5 Appendix provides a guide for representing specifiers or subtypes via the final digits of the ICD-9-CM or ICD-10 diagnostic codes.

As noted above, the multi-axial format has been eliminated in DSM-5. All psychiatric and medical diagnoses that are relevant to care should be listed in order of clinical concern, with the most important diagnosis prompting the clinical encounter listed first. These may include diagnoses involving the interplay between medical and psychiatric conditions. For example, substance ingestion may be thought to cause the psychiatric problem, resulting in a diagnosis such as “substance-induced psychotic disorder.” Alternatively, a medical illness can be understood as provoking the mental disorder, leading to a diagnosis in the format “[psychiatric disorder] due to [another medical condition]” ( Box 17-2 ). Subthreshold psychiatric symptoms (e.g., anxiety or over-eating), personality traits or defenses, maladaptive coping (e.g., non-adherence to medical care) or physiological stress responses that have a negative impact on the course of a medical condition are given a diagnosis of “psychological factors affecting other medical conditions” (see Box 17-2 ). In addition “other conditions that may be the focus of clinical attention” may be listed, including as many problems or stressors as are relevant to diagnosis and clinical management ( Table 17-1 ). These conditions are typically listed with their corresponding ICD code (V codes for ICD-9, Z codes for ICD-10).

Section III

Section III contains a collection of new material. Analogous to Appendix B of DSM-IV-TR, Section III lists candidate disorders that require additional research before consideration for inclusion in future revisions. These include such constructs as Internet Gaming Disorder and Non-suicidal Self-Injury.

In addition, Section III presents a Cultural Formulation Interview to assist in gathering culturally-relevant information affecting diagnosis and treatment-planning with diverse populations. DSM-5 introduces a more fine-grained approach to understanding how culture may impact clinical care to replace the “culture-bound syndromes” of DSM-IV-TR. A glossary in the appendix describes important cultural concepts of distress. These include cultural syndromes (such as ataque de nervios ), cultural idioms of distress (such as kufungisisa ), and cultural explanations (such as maladi moun ). Information on cultural variation in clinical presentations is also included in the description of specific disorders in Section II. For example, in the discussion of pica, it is noted that some groups may ascribe spiritual value to the eating of specific non-food substances, which should not be diagnosed as a mental disorder.

A major critique of DSM-IV-TR focused on limitations of the categorical model and encouraged the inclusion of dimensional approaches in future editions. Based on these critiques, DSM-5 offers incremental changes toward a dimensional model of diagnosis. A standardized measure of “cross-cutting symptoms,” such as anger and sleep problems, which appear in multiple psychiatric disorders, is featured in Section III of the DSM-5. In addition, a dimensional measure of psychosis symptom-severity is included. Given that the GAF has been removed from DSM-5, an alternative measure for assessing disability, the WHO Disability Assessment Schedule 2.0 (WHODAS 2.0) is provided.

Work has also been conducted along dimensional lines in the area of personality disorders research. Although the APA opted to keep the system for diagnosing personality disorders unchanged in Section II of DSM-5 ( Table 17-2 ), a different way to conceptualize personality disorders is introduced in Section III. This model considers four areas of personality functioning: identity, self-direction, empathy, and intimacy. In addition, personality traits falling within one of five domains (for example, negative affectivity) are assessed, each featuring more specific “trait facets” (such as emotional lability or hostility).