Chapter 6. Obsessive-Compulsive and Related Disorders

When evaluating a patient whose preoccupations and rituals have become persistent, excessive, and impairing, clinicians are encouraged to consider each of the disorders within the chapter on obsessive-compulsive and related disorders. These include obsessive-compulsive disorder, body dysmorphic disorder, hoarding disorder, trichotillomania (hair-pulling disorder), and excoriation (skin-picking) disorder. Obsessive-compulsive disorder (OCD) is characterized by the presence of obsessions and/or compulsions. Obsessions are unwanted and repetitive thoughts that often involve such concerns as pathological doubt, fear of contamination, somatic concerns, and a need for symmetry. Compulsions are the repetitive behaviors that are performed in response to the distress of the obsessions. Common compulsive behaviors include checking, ordering, cleaning, and mental rituals. Body dysmorphic disorder (BDD) is characterized by a preoccupation with one or more physical flaws that are not readily apparent to others. In addition, a diagnosis of BDD requires repetitive behaviors (such as excessive grooming or reassurance seeking) and significant distress or dysfunction. If the preoccupation is primarily about weight, however, then that patient would receive an eating disorder diagnosis if diagnostic criteria for an eating disorder are met. Once a diagnosis is made, DSM-5 includes multiple specifiers for many of its diagnoses. OCD, BDD, and hoarding disorder are unusual in having an “insight” specifier. The insight specifier characterizes patients as having good or fair insight, poor insight, or absent insight/delusional beliefs. For example, people who are delusionally convinced that their BDD beliefs are true would not be coded as having a comorbid psychotic disorder (e.g., delusional disorder) but would instead be noted to have BDD with absent insight. Trichotillomania (hair-pulling), and excoriation (skin-picking) are the most common body-focused, repetitive behavior disorders. Hair-pulling disorder was previously listed among the impulse-control disorders not elsewhere classified, along with such disorders as pyromania and intermittent explosive disorder. Skin-picking disorder was new in DSM-5. Both disorders involve the sort of persistent, repetitive dysfunctional behaviors that characterize all of the obsessive-compulsive and related disorders. Hoarding disorder was also new in DSM-5. It was previously listed as a possible criterion for obsessive-compulsive personality disorder or considered a symptom of OCD. In some cases, hoarding-type behavior is a symptom of OCD (e.g., if trash accumulates because of fears of becoming contaminated by touching it), but evidence indicates that dysfunctional hoarding often exists without an accompanying OCD diagnosis. As continues to be true throughout much of DSM-5, this chapter includes categories for patients whose symptoms are assessed to be secondary to medications, substances, or another medical condition. DSM-5 also allows clinicians to identify clinically relevant conditions that do not meet full criteria for a disorder. For example, a presentation that meets criteria for body dysmorphic disorder in a person who has significant physical flaws—a circumstance that would preclude the use of that diagnosis (which requires that any physical flaws be no more than “slight”)—could be recorded as “other specified obsessive-compulsive and related disorder (body dysmorphic–like disorder with actual flaws).” The “other specified” diagnosis might also be used to refer to a symptom cluster not described in the criteria for any DSM-5 obsessive-compulsive and related disorder, such as obsessional jealousy or olfactory reference disorder. “Unspecified” disorders can refer to symptom clusters that resemble presentations found in a particular DSM-5 chapter but that do not meet criteria for any specific disorder; the unspecified diagnosis is often used when the clinician has insufficient clinical information to make a diagnosis, such as in an emergency evaluation or an initial consultation.