When should a diagnosis of Obsessive-Compulsive Disorder (OCD) be considered in a patient?

When to Give an OCD Diagnosis

Diagnose OCD when a patient presents with obsessions and/or compulsions that consume more than 1 hour per day AND cause clinically significant distress or functional impairment, after ruling out that these symptoms are better explained by another mental disorder, substance use, or medical condition. 1

Core Diagnostic Criteria

The diagnosis requires presence of obsessions and/or compulsions with two additional critical elements 1:

Clinical Significance Criterion

• The obsessions or compulsions must be time-consuming (taking up more than 1 hour per day) AND cause substantial distress or functional impairment. 1 This threshold is essential because intrusive thoughts and repetitive behaviors are common in the general population and rituals are a normal part of development. 1

Diagnostic Hierarchy Criterion

• The symptoms cannot be better explained by another mental disorder, nor attributable to physiological effects of a substance (drug of abuse or medication) or another medical condition. 1 This exclusion criterion prevents misdiagnosis when obsessive-compulsive symptoms are secondary phenomena. 2

Defining Obsessions and Compulsions

Obsessions are:

• Recurrent, persistent, intrusive thoughts, urges, images, or impulses that are ego-dystonic (unwanted and distressing to the patient). 3, 4, 5
• Recognized by the patient as excessive or unreasonable, even if they cannot stop them. 6, 7
• Anxiety-provoking and actively resisted by the patient. 7
• Typically involve themes of contamination, harm, symmetry, or forbidden thoughts perceived as threatening. 6

Compulsions are:

• Repetitive, purposeful, intentional behaviors or mental acts (such as counting, praying, or repeating words silently). 6, 3, 4
• Performed in response to an obsession or in a stereotyped fashion to reduce anxiety or prevent dreaded outcomes. 6, 7, 3
• Recognized by the patient as excessive or unreasonable. 7, 3, 4

Critical Differential Diagnoses

Distinguishing OCD from Normal Intrusive Thoughts

• Common intrusive thoughts (such as thoughts of harming oneself or others, double-checking locks) become OCD only when time-consuming (>1 hour/day) and causing substantial distress or functional impairment. 1

Distinguishing OCD from Generalized Anxiety Disorder and Depression

• Worries and ruminations in GAD and depression are typically about real-life concerns and less irrational and ego-dystonic than OCD obsessions. 1
• Compulsions are not typically seen in GAD or depression. 1
• Ask: "Do these thoughts feel like they're intruding against your will, or are they topics you enjoy thinking about?" and "Do these thoughts cause you anxiety or distress, or do they feel comforting?" 6

Distinguishing OCD from Autism Spectrum Disorder

• OCD rumination is ego-dystonic (unwanted, anxiety-provoking), while ASD rumination is ego-syntonic (comfortable, part of routine). 6
• OCD involves marked distress and impairment with active attempts to suppress thoughts, whereas ASD involves comfortable repetitive thinking without distress. 6
• Severe OCD may secondarily impair social functioning, but does not cause primary social-communication deficits like ASD. 6

Distinguishing OCD from Psychotic Disorders

• OCD obsessions are recognized as excessive or unreasonable (good/fair insight), while delusions are fixed false beliefs held with conviction without recognition of unreasonableness (absent insight). 7, 8
• Patients with OCD and absent insight/delusional beliefs are convinced their OCD beliefs are true; this subtype must be recognized and appropriately treated rather than erroneously diagnosed as psychotic disorder. 1
• Ask: "Do these thoughts feel like they're intruding against your will, or do they feel like accurate beliefs about reality?" 7

Distinguishing OCD from Other OCRDs

• Recurrent thoughts and rituals occur in body dysmorphic disorder, hoarding disorder, trichotillomania, and excoriation disorder, but the foci of apprehension and form of repetitive behaviors are distinct from OCD. 1

Distinguishing OCD from Substance-Related and Impulse-Control Disorders

• These disorders often have an ego-syntonic, gratifying component, particularly in the short term, unlike the ego-dystonic nature of OCD. 1

Structured Assessment Approach

Clinical Interview

• Conduct a detailed psychiatric history and mental status examination as the core assessment. 1
• Assess emotional valence: whether thoughts are intrusive and unwanted versus comfortable. 6
• Evaluate mental acts (counting, praying, repeating words silently) performed rigidly in response to obsessions. 6
• Determine insight level: whether patient recognizes thoughts as excessive even if unable to stop them. 6, 7

Standardized Diagnostic Instruments

• Use the Structured Clinical Interview for DSM-5 (SCID-5) for adults or Anxiety Disorders Interview Schedule for DSM-5 (ADIS-5) for adults and children. 1
• The Mini International Neuropsychiatric Interview (MINI version 7.0) is a shorter alternative for adults and children/adolescents. 1

Severity Assessment

• Use the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) or Children's Y-BOCS (CY-BOCS) to quantify symptom severity. 1
• Scores ≥14 for obsessions alone indicate clinically significant OCD requiring treatment. 6, 8
• The Y-BOCS measures time spent (>1 hour/day), distress levels, and functional impairment independent of obsession content. 8
• The Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) allows detailed assessment of OCD symptom dimensions. 1

Important Specifiers to Document

Insight Specifiers (DSM-5)

• With good or fair insight: Patient recognizes OCD beliefs are not true or may not be true. 1
• With poor insight: Patient thinks OCD beliefs are probably true. 1
• With absent insight/delusional beliefs: Patient is completely convinced OCD beliefs are true. 1

Tic Specifier

• Document current or past tic disorder, as patients with OCD with or without tics differ in phenomenology and psychobiology requiring tailored management. 1
• Males are more likely to have early-onset OCD (before puberty) and comorbid tics. 1

Common Diagnostic Pitfalls

• Failing to assess the 1-hour time threshold: Intrusive thoughts are common; diagnosis requires >1 hour/day consumed by symptoms. 1
• Misdiagnosing OCD with absent insight as psychotic disorder: This leads to inappropriate treatment; recognize this as an OCD subtype. 1
• Overlooking mental compulsions: Assess for covert mental acts (counting, praying, repeating), not just overt behavioral rituals. 6
• Confusing ego-dystonic OCD rumination with ego-syntonic ASD preoccupations: The emotional valence and distress level distinguish these conditions. 6
• Missing comorbid conditions: Depression and personality disorders commonly co-occur with OCD and should be assessed. 2

Clinical Impact Justifying Diagnosis

• OCD causes quality of life impairment comparable to schizophrenia, with significant dysfunction across work, family, and social domains. 8, 9
• Patients often have difficulty maintaining employment, finishing school, and developing relationships. 10
• The disorder typically begins during adolescence or early adulthood and can have a chronic or deteriorating course without effective treatment. 5