Obsessive-Compulsive Disorder (OCD)
Intrusive ego-dystonic obsessions and ritualized compulsions consuming >1 hour/day or causing impairment.
Also known as: OCD, obsessive-compulsive disorder
Overview
Presence of obsessions (recurrent, intrusive, unwanted thoughts/images/urges) and/or compulsions (repetitive behaviors or mental acts performed to reduce distress or prevent a feared outcome) that are time-consuming (>1 hour/day) or cause clinically significant distress/impairment.
Epidemiology
Lifetime prevalence ~2-3%. Bimodal onset: childhood/early adolescence (males) and early adulthood (females). Often chronic with waxing/waning course.
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Risk factors
- Family history (first-degree relative 4x risk; higher with childhood-onset proband)
- Streptococcal infection (PANDAS) in pediatric cases
- Adverse childhood experiences, perinatal complications
- Comorbid tic disorder, Tourette syndrome
Pathophysiology
Cortico-striato-thalamo-cortical (CSTC) circuit dysfunction with hyperactivity of orbitofrontal cortex, anterior cingulate, and caudate; serotonergic and glutamatergic dysregulation. Heritability ~50%.
Clinical presentation
Symptoms
- Common obsession themes: contamination, harm/aggression, symmetry/exactness, taboo (sexual/religious/violent), somatic
- Common compulsion themes: washing/cleaning, checking, counting, ordering, mental rituals (e.g., praying, repeating phrases), reassurance seeking
- Patients recognize obsessions as their own and excessive (insight varies)
- Avoidance of trigger situations (e.g., public restrooms)
Signs / physical exam
- Dermatitis or skin damage from washing
- Time-consuming routines reported by family
- Y-BOCS score >=16 supports moderate symptoms
Differential diagnosis
- GAD — Worries are about real-life concerns, not ego-dystonic; no ritualized neutralizing behaviors
- Obsessive-compulsive personality disorder — Ego-syntonic perfectionism and rigidity without true obsessions/compulsions
- Body dysmorphic disorder — Preoccupation with perceived appearance flaws; compulsive mirror-checking
- Hoarding disorder — Difficulty discarding due to perceived need to save items; clutter impairs use of living space
- Trichotillomania / excoriation — Repetitive hair-pulling or skin-picking without true obsessions
- Tic disorder / Tourette — Premonitory urge with sudden non-purposeful movements; can co-occur with OCD
- Psychotic disorder — Obsessions in OCD are recognized as one's own; psychotic delusions are held with full conviction
Diagnostic workup
Diagnostic criteria
DSM-5-TR: Presence of obsessions, compulsions, or both; obsessions are recurrent intrusive thoughts/urges/images causing anxiety, which the person attempts to ignore/suppress or neutralize with another thought or action; compulsions are repetitive behaviors/mental acts the person feels driven to perform in response to an obsession or rigid rule, aimed at preventing or reducing distress, not realistically connected or clearly excessive. Time-consuming (>1 hr/day) or causes significant distress/impairment. Specify level of insight.
Labs
- Targeted history; routine labs not required
- Throat culture or ASO/anti-DNase B if abrupt pediatric onset (PANDAS suspected)
Imaging
- Not routinely indicated
Diagnostic algorithm
| Symptom dimension | Typical obsession | Typical compulsion |
|---|---|---|
| Contamination | Fear of germs/illness | Washing, cleaning, avoidance |
| Harm | Fear of harming self/others | Checking, reassurance seeking |
| Symmetry | Need for things 'just right' | Ordering, counting, repeating |
| Taboo | Unwanted sexual/violent/religious thoughts | Mental rituals, praying, confession |
| Hoarding (now separate dx) | Distress at discarding | Saving, acquiring |
Treatment
First-line
- Cognitive behavioral therapy with exposure and response prevention (ERP) — most effective intervention
- SSRI at higher doses than for depression — fluoxetine, sertraline, fluvoxamine, paroxetine, escitalopram (off-label)
- Clomipramine (TCA with strong serotonergic activity) — comparable efficacy; reserved for SSRI nonresponders due to side effects
- Combine ERP + SSRI for severe symptoms
Second-line / adjunct
- Augmentation with atypical antipsychotic (risperidone, aripiprazole) for SSRI partial response, particularly with comorbid tics
- Glutamatergic agents (memantine, N-acetylcysteine) — emerging evidence
- Deep brain stimulation for severe, intractable OCD in specialized centers
- Intensive residential ERP programs for treatment-resistant cases
Complications
- Functional impairment, social isolation, occupational decline
- Comorbid depression (~30-50%), anxiety disorders, tic disorders
- Skin breakdown from washing rituals
- Suicidal ideation in severe disease
PANCE pearls
- OCD requires higher SSRI doses than depression (e.g., fluoxetine 40-80 mg, sertraline 150-200 mg) and longer trials (10-12 weeks) before declaring failure.
- Insight specifier ranges from good/fair to absent/delusional — does not change diagnosis from OCD to psychosis.
- PANDAS: abrupt-onset pediatric OCD or tics temporally linked to streptococcal infection; controversial but recognized entity.
- Family accommodation (relatives participating in or enabling rituals) predicts worse outcomes — address in treatment.
References
- APA 2007 — American Psychiatric Association Practice Guideline for the Treatment of Patients with Obsessive-Compulsive Disorder (2007)
- NICE CG31 — NICE Clinical Guideline 31: OCD and BDD
- DSM-5-TR — American Psychiatric Association. DSM-5-TR (2022)
- Y-BOCS — Goodman WK et al. The Yale-Brown Obsessive Compulsive Scale. Arch Gen Psychiatry 1989
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