Diagnosing Obsessive-Compulsive Disorder
OCD diagnosis is clinical and requires the presence of obsessions and/or compulsions that consume more than 1 hour per day or cause marked distress and significantly interfere with social or occupational functioning. 1
Core Diagnostic Criteria
The diagnosis follows DSM criteria and must include: 1
- Time criterion: Symptoms consuming >1 hour per day 1
- Distress criterion: Marked psychological distress from the obsessions or compulsions 1, 2, 3
- Functional impairment: Significant interference with social or occupational functioning 1, 2, 3
Defining Obsessions and Compulsions
- Obsessions are recurrent, persistent ideas, thoughts, impulses, or images that are ego-dystonic (experienced as intrusive and unwanted) 2, 3, 4
- Compulsions are repetitive, purposeful, and intentional behaviors performed in response to an obsession or in a stereotyped fashion, recognized by the person as excessive or unreasonable 2, 3, 4
Common Symptom Dimensions to Assess
When evaluating for OCD, specifically inquire about these symptom clusters: 1
- Contamination concerns with subsequent cleaning/washing rituals 1
- Harm-related obsessions with subsequent checking compulsions 1
- Symmetry/ordering concerns with arranging/ordering compulsions 1
- Relationship-themed obsessions (including doubts about partner, sexual orientation concerns) 5
- Somatic, aggressive, or sexual intrusive thoughts 6
- Fear of contamination by dirt or germs 6
- Extreme slowness and inordinate concern with orderliness 6
Structured Assessment Tools
The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is the gold standard clinician-rated assessment tool for measuring OCD severity. 5, 1
- The Y-BOCS measures time spent on obsessions/compulsions, distress levels, and functional interference independent of symptom content 5, 1
- A clinical threshold is defined as Y-BOCS scores indicating symptoms consuming >1 hour/day or causing significant distress/impairment 5, 1
- The Y-BOCS should be administered by clinicians trained in recognizing OCD presentations to ensure accurate scoring 5
- Baseline Y-BOCS scores in moderate-to-severe OCD typically range from 26-28 3
Critical Differential Diagnoses
Schizotypal Personality Disorder vs. OCD
- Schizotypal Personality Disorder presents with pervasive referential ideas, magical thinking across situations, and social/interpersonal deficits beyond OCD avoidance 7, 1
- Evaluate whether magical thinking is pervasive or limited to OCD rituals 7
- Assess if "fear of being judged" represents true referential thinking or realistic social anxiety 7
Social Anxiety Disorder with Comorbid OCD
- Social Anxiety Disorder involves marked fear of being judged or scrutinized in social/performance situations, which can coexist with separate OCD symptoms 7, 4
- Distinguish realistic fear of social judgment from OCD-related obsessions 7
Obsessive-Compulsive Personality Disorder (OCPD)
- OCPD involves ego-syntonic perfectionism and rigidity, whereas OCD involves ego-dystonic intrusive thoughts 6
- Patients with OCPD do not experience their traits as distressing or unreasonable 6
Comorbidity Assessment
Ninety percent of OCD patients meet criteria for another lifetime disorder, making comorbidity assessment essential. 1
- Most common comorbidities: Anxiety disorders, mood disorders (particularly depression), impulse-control disorders, and substance use disorders 1, 6
- Depression is the most common complication of OCD 6
- Tic disorders and other obsessive-compulsive related disorders commonly co-occur 1
- Screen for eating disorders, somatoform disorders, and impulse control disorders as part of the OCRD spectrum 8
Severity and Functional Impact Documentation
- Document that 65.3% of 12-month OCD cases result in severe role impairment on the Sheehan Disability Scale 1
- Affected individuals experience an average of 45.7 days out of role per year 1
- OCD is associated with increased mortality 1
Age-Specific Considerations
- Males: Nearly 25% have onset before age 10 1
- Females: Typically experience onset during adolescence 1
- Peak risk: Lifetime onset occurs between ages 18-29 years 1
- OCD affects 2-3% of adults worldwide 9, 6
Common Diagnostic Pitfalls
- Patients often conceal symptoms due to shame and fear of stigma, creating an average 10-year delay in diagnosis 9
- Screen for OCD in every mental status examination rather than waiting for patients to volunteer symptoms 6
- Do not rely solely on patient self-report; use structured assessment tools like the Y-BOCS 5, 1
- Assess for family accommodation, as relationship partners may inadvertently reinforce symptoms through reassurance-giving or participation in rituals 5
Treatment Approach
First-Line Treatment
Cognitive-behavioral therapy with exposure and response prevention (ERP) is the most effective treatment for OCD. 9, 10
- CBT with ERP should be offered as first-line treatment when available 9, 10
- Treatment response is indicated by ≥35% reduction in Y-BOCS score 1, 3
Pharmacotherapy
If CBT is not effective or not available, initiate pharmacotherapy with an SSRI as first-line medication. 9, 11
- FDA-approved SSRIs for OCD: Sertraline 2, paroxetine 4, and fluoxetine
- Clomipramine (a nonselective serotonin reuptake inhibitor) is also FDA-approved but reserved due to inferior tolerability compared to SSRIs 3, 9, 11
- Treatment duration: 10-12 weeks at adequate doses before assessing response 8, 11
- Doses and duration differ from depression treatment: OCD typically requires higher doses and longer trials 8
- Mean reduction of approximately 10 points on Y-BOCS (35-42% improvement) is expected with effective treatment 3
Treatment-Resistant OCD
For patients not responding to first-line treatments: 9, 11
- Switch to a different SSRI 11
- Combine medication with behavioral therapy 11
- Consider pharmacological augmentation strategies 8, 11
- Neuromodulation approaches (deep brain stimulation, transcranial magnetic stimulation) for treatment-resistant cases 9, 8