Obsessive-Compulsive Disorder

Excerpt

Obsessive-compulsive disorder (OCD) is a disabling condition estimated to affect 1% to 3% of individuals throughout their lifetime. This psychiatric disorder is characterized by obsessions and compulsions, which consume a significant amount of time and lead to notable distress and impairment. Obsessions refer to intrusive and repetitive thoughts, urges, or mental images that are challenging to control. These thoughts often lack a clear purpose and are accompanied by distress. Compulsions involve repetitive actions or mental events that individuals with OCD feel compelled to perform to alleviate the distress caused by the obsessions or to prevent a feared consequence from occurring. Additionally, individuals with OCD may also engage in avoidance behaviors of obsession-triggering situations.

OCD is a heterogeneous condition that arises from a complex interplay of genetic and environmental risk factors. Most adults are distressed by the ego-dystonic nature of their obsessions and are aware that their compulsive behaviors are abnormally excessive. Children often have difficulty describing their obsessions. In OCD patients, common obsessions and their associated compulsive behaviors include fear of contamination leading to excessive cleaning, fear of harm linked to repetitive checking of security measures, intrusive, aggressive, or sexual thoughts paired with mental rituals, and a focus on symmetry accompanied by ordering or counting. Though hoarding behaviors are usually specific to hoarding disorder, they can occur in OCD to prevent perceived harm. These behavior sets are consistently observed worldwide, suggesting a degree of commonality in OCD symptom dimensions. OCD can also present with rarer symptoms, including scrupulosity, obsessive jealousy, and musical obsessions.

The understanding of OCD has evolved significantly over time. Historically framed in religious terms as a moral failing or demonic possession, OCD was first medically described by Esquirol. Freud subsequently characterized the condition using the term obsessive neurosis, positing that OCD originated with a regression in the anal phase of psychosexual development. In the third edition of the Diagnostic and Statistical Manual (DSM-III), OCD was grouped with phobias under a single diagnosis. Later, the DSM-IV classified the condition as an anxiety disorder. The DSM-5 has reclassified OCD into the category "Obsessive-Compulsive and Related Disorders," alongside conditions like hoarding and body dysmorphia. This reclassification acknowledges shared characteristics, such as phenomenology, comorbidity, and underlying neurobiological factors. WHO lists OCD as 1 of the 10 most disabling conditions caused by financial loss and decreased quality of life. In The Diagnostic and Statistical Manual of Mental Disorders fifth edition Text Revision (DSM-5 TR), which was published by the American Psychiatric Association (APA) in 2022, OCD sits under the category of obsessive-compulsive and related disorders where the following subcategories were placed:

1. OCD

2. Body dysmorphic disorder (BDD)

3. Hoarding disorder

4. Trichotillomania

5. Excoriation (ie, skin-picking) disorder

6. Substance or medication-induced obsessive-compulsive and related disorder

7. Obsessive-compulsive and related disorder as a result of another medical condition

8. Other specified obsessive-compulsive and related disorder

9. Unspecified obsessive-compulsive and related disorder

The diagnosis of OCD is based on clinical assessment determining whether the DSM-5 TR criteria are met, which specify that either obsessions or compulsions must be present, the behaviors must be time-consuming, taking ≥1 hour per day, and significantly disrupting daily life. (Refer to the History and Physical Examination section for more information on the diagnostic criteria for OCD).