This supplement to CNS Spectrums focuses on the obsessive-compulsive spectrum of disorders and their relationship to anxiety. Hollander and others pioneered the concept of the obsessive-compulsive spectrum in the early 1990s, and have described its breadth and overlap with other psychiatric disorders. While its place in the psychiatric nomenclature is uncertain, the obsessive-compulsive spectrum is intertwined with the anxiety disorders in both its symptoms and biologic substrates.

Obsessive-compulsive disorder (OCD) has an important place at the center of the spectrum. While currently classified in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition as an anxiety disorder, OCD is distinct from these conditions in the International Classification of Diseases. There is a strong rationale for its separation from the anxiety disorders. First, OCD often begins in childhood, whereas other anxiety disorders typically have a later age of onset. OCD has a nearly equal gender distribution, unlike the other anxiety disorders, which are more common in women. Studies of psychiatric comorbidity show that, unlike the other anxiety disorders, persons with OCD generally tend not to have elevated rates of substance misuse. Family studies suggest that first-degree relatives of persons with OCD have an elevated prevalence of OCD-related disorders including body dysmorphic disorder, hypochondriasis, and grooming disorders, but not other anxiety disorders except for generalized anxiety disorder. The brain circuitry that mediates OCD appears to be different from that involved in other anxiety disorders. Lastly, OCD is unique with regard to its specific response to selective serotonin reuptake inhibitors, while noradrenergic medications, effective in the anxiety and mood disorders, are largely ineffective. On the other hand, the benzodiazepines, which have little effect on OCD, are often effective for the other anxiety disorders.

As a result of clinical, epidemiological, neuroimaging, and therapy studies that took place in the late 1980s, obsessive-compulsive disorder (OCD) has been well-characterized in the field of anxiety disorders. Other disorders attracted attention for their similarities to OCD, and were located in the orbit of the disorder. OCD has become known as the “primary domain” of a scientific “metaphor” comprising the putative cluster of OCD-related disorders (OCRDs). It is a “paradigm” with which to explore basal ganglia dysfunction. The OCRDs share common phenomenology, comorbidities, lifetime course, demographics, possible genetics, and frontostriatal dysfunction (particularly caudate hyperactivity.) The adoption of this metaphor analogy has proven useful. However, 15 years since its emergence, the spectrum of obsessive-compulsive disorders remains controversial. Questions under debate include whether OCD is a unitary or split condition, whether it is an anxiety disorder, and whether there exists only one spectrum or several possible spectrums. Further work is needed to clarify obsessive-compulsive symptoms, subtypes, and endophenotypes. There is need to integrate existing databases, better define associated symptom domains, and create a more comprehensive endophenotyping protocol for OCRDs. There is also a need to integrate biological and psychological perspectives, concepts, and data to drive this evolution. By increasing research in this field, the OCD spectrum may evolve from a fragmented level of conceptualization as a “metaphor” to one that is more comprehensive and structured.

Quality of life (QoL) is increasingly recognized as a pivotal outcome parameter in research on obsessive-compulsive disorder (OCD). While the concept remains somewhat ill-defined, there is now little dispute that the patients’ personal goals deserve foremost consideration during the course of treatment as the primary aim of treatment should be relief from individual despair, which is related but by no means synonymous to symptom reduction. Studies using generic (ie, illness-unspecific) instruments have confirmed poor QoL in OCD patients across a wide range of domains, especially with respect to social, work role functioning, and mental health aspects. Scores are sometimes as low as those obtained by patients with schizophrenia. Depression and obsessions are the symptom clusters that most strongly contribute to low QoL. Findings from a novel survey of 105 OCD participants point to multiple daily life problems, poor work status, and tense social networks in these patients. In order to achieve therapeutic success and improve QoL, functional problems at work and comorbid disorders such as secondary depression and physical impairments should be targeted. While successful treatment sometimes positively impacts well-being, in some studies symptom decline did not translate into improved QoL.

Obsessive-compulsive disorder is currently classified as an anxiety disorder. However, there is growing interest in the concept of an obsessive-compulsive spectrum of disorders (OCSDs). The relationship between anxiety disorders and OCSDs has been questioned. The psychobiology of anxiety disorders and OCSDs is briefly reviewed in this article. While there appear to be several distinct contrasts in the underlying psychobiology of these conditions, there is also evidence of overlapping mechanisms. In addition, there are crucial gaps in our current database, confounding nosological decision-making. Conceptualizing various anxiety disorders and putative OCSDs as lying within a broader spectrum of emotional disorders may be useful. However, clinicians must also recognize that individual anxiety and obsessive-compulsive spectrum conditions, including disorders characterized by body-focused repetitive behaviors, have distinct psychobiological underpinnings and require different treatment approaches.

Compulsive hoarding is a common and often disabling neuropsychiatric disorder. This article reviews the phenomenology, etiology, neurobiology, and treatment of compulsive hoarding. Compulsive hoarding is part of a discrete clinical syndrome that includes difficulty discarding, urges to save, clutter, excessive acquisition, indecisiveness, perfectionism, procrastination, disorganization, and avoidance. Epidemiological and taxometric studies indicate that compulsive hoarding is a separate but related obsessive-compulsive spectrum disorder that is frequently comorbid with obsessive-compulsive disorder (OCD). Compulsive hoarding is a genetically discrete, strongly heritable phenotype. Neuroimaging and neuropsychological studies indicate that compulsive hoarding is neurobiologically distinct from OCD and implicate dysfunction of the anterior cingulate cortex and other ventral and medial prefrontal cortical areas that mediate decision-making, attention, and emotional regulation. Effective treatments for compulsive hoarding include pharmacotherapy and cognitive-behavioral therapy. More research will be required to determine the etiology and pathophysiology of compulsive hoarding, and to develop better treatments for this disorder.

Selective serotonin reuptake inhibitors (SSRIs) are first-line pharmacotherapy treatments for obsessive-compulsive disorder (OCD). Clomipramine is effective in OCD but associated with more adverse events. Typically, higher doses of antidepressants are required for OCD. Up to 50% of patients do not respond to initial treatment of OCD. Treatment options for nonresponders include augmentation of antidepressants with atypical antipsychotics, among other strategies. First-line treatments for anxiety disorders include SSRIs, serotonin norepinephrine reuptake inhibitors, and pregabalin. Tricyclic antidepressants are equally effective as SSRIs, but are less well tolerated. In treatment-resistant cases, benzodiazepines may be used when the patient does not have a history of dependency and tolerance. Other treatment options include irreversible and reversible monoamine oxidase inhibitors, the atypical antipsychotic quetiapine, and other medications. Cognitive-behavioral therapy has been sufficiently investigated in controlled studies of OCD and anxiety disorders and is recommended alone or in combination with the above medications.

Both obsessive-compulsive disorder (OCD) and social phobia are common in community and clinical settings, and it should be expected that a proportion of patients with one of these conditions will also fulfill either current or lifetime criteria for the other condition. However, comorbid social phobia is more common among patients with a primary diagnosis of OCD than is comorbid OCD in patients with a primary diagnosis of social phobia. This article explores the extent of the association of OCD and social phobia in epidemiological studies, and examines the possible role of underlying depression and other disorders in mediating the appearance of the comorbid condition. Although there have been no published randomized controlled trials in patients with this particular pattern of co-morbidity, it seems sensible to adopt pharmacologic and psychologic treatment approaches which have been found efficacious in both OCD and social phobia. Pharmacologic management therefore centers on first-line treatment with a selective serotonin reuptake inhibitor. Psychologic intervention should draw on the range of cognitive and behavioral approaches required for optimal outcomes in OCD and social phobia, as discrete conditions.

Introduction: The concept of subclinical obsessive-compulsive disorder is explored using data from a “high-risk” study of offspring of persons with (OCD) and offspring of controls. Offspring with OCD were compared to those with subclinical OCD, and those without either condition. Subclinical OCD is defined as the presence of obsessions and/or compulsions without functional impairment.

Methods: Adults with OCD and their offspring 7–18 years of age were recruited through a tertiary care center psychiatric outpatient clinic, while controls (and their children) were recruited via advertisement. Parents and offspring were assessed using structured interviews and validated questionnaires at baseline and follow-up interviews.

Results: Offspring from both proband groups were pooled to create three subject groups: group 1, offspring with neither condition (n=43); group 2, offspring with subclinical OCD (n=24); and group 3, offspring with full OCD (n=11). Offspring with subclinical OCD held the middle ground for most comparisons. They were more symptomatic than offspring without either condition (group 1), but less symptomatic than subjects with OCD (group 3). Across the board, comparisons of diagnoses, Child Behavior Checklist (CBCL) results; Motor tic, Obsessions and compulsions, Vocal tic Evaluation Survey results; and Leyton Obsessional Inventory (LOI) results were associated with subject group at baseline and follow-up. In post-hoc comparisons, subjects with subclinical OCD had fewer comorbid anxiety disorders and lower CBCL internalizing scale scores at follow-up. Parents of children with OCD had higher LOI symptom and severity scores than parents in those of groups 1 or 2.

Conclusion: The findings suggest that subclinical OCD holds the middle ground between full-blown OCD and having neither condition in terms of obsessive-compulsive symptoms and severity, tics, associated mood/anxiety disorders, and general functioning. At least in persons at risk for OCD, the presence of subclinical OCD may herald the onset of OCD, though in others may be an independent condition that does not lead to full OCD.