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Obsessive-Compulsive Disorder (OCD)

BASICS

Description

  • Behavioral disorder with pathologic obsessions (recurrent intrusive thoughts, ideas, images) and/or compulsions (repetitive, ritualistic behaviors/mental acts) causing significant distress
  • Distinct from obsessive-compulsive (anankastic) personality disorder

EPIDEMIOLOGY

  • Incidence:
  • Subtypes: child/adolescent-onset (<18 yrs), adult-onset (18–39 yrs), late-onset (≥40 yrs)
  • 50% of cases begin before age 18
  • Lifetime prevalence ≈2%
  • Slight female predominance (esp. postpartum OCD)
  • Pediatrics: Consider PANDAS (autoimmune streptococcal) in acute childhood OCD
  • Geriatrics: Consider neurodegenerative disorders in late-onset cases

ETIOLOGY AND PATHOPHYSIOLOGY

  • Neurobiology:
  • Dysregulation of serotonergic, catecholaminergic, and glutamatergic pathways
  • Dysfunction in cortico-striatal-thalamo-cortical (CSTC) circuit
  • Triggers: Brain injury, trauma, infections (streptococcus)
  • Genetics: 7–15% prevalence in 1st-degree relatives; genetics explain ~45–65% of risk

RISK FACTORS

  • Family history
  • Advanced parental age
  • Comorbid psych disorders (anxiety, schizophrenia)
  • Low serotonin, some antipsychotic use (esp. clozapine/olanzapine)
  • Brain insult, childhood trauma/social isolation

PREVENTION

  • Early diagnosis and treatment reduce distress and impairment

COMMONLY ASSOCIATED CONDITIONS

  • Mood & Anxiety: Major depressive disorder, panic, GAD, phobias
  • Neurodevelopmental: Tic disorders, Tourette syndrome, PANDAS
  • Behavioral: Trichotillomania, excoriation, hoarding, substance/eating/body dysmorphic disorder

DIAGNOSIS

History

  • Obsessions: Intrusive, persistent thoughts causing anxiety/distress; patient tries to suppress or neutralize with compulsions
  • Compulsions: Repetitive behaviors or mental acts performed to reduce anxiety, but not realistically connected or are excessive
  • Diagnostic criteria: Marked distress, time-consuming (>1 hr/day), functional impairment
  • Context: Religious obsessions (adolescents); sexual obsessions (adults)
  • Insight: Many patients know beliefs are unlikely but cannot suppress rituals
  • Delay: Average 11 years to treatment; rapport essential

Physical Exam

  • Signs of compulsions: chapped hands, sores/scars (skin picking/biting), patchy hair loss, weight loss (contamination fears)

Differential Diagnosis

  • Impulse-control disorders (gambling, sex, substance)
  • Tic/stereotypic movement disorders (no obsessions)
  • Generalized anxiety/phobic/separation anxiety (no compulsion)

Diagnostic Tests

  • Clinical diagnosis: DSM-5 criteria
  • Structured interview: Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) for severity

Common Themes

  • Obsessions: Harm, doubt, blasphemy, sexual thoughts, contamination, symmetry
  • Compulsions: Washing/cleaning, checking, counting, ordering, hoarding, repeating

TREATMENT

General Measures

  • First-line: Exposure with response prevention (ERP)—CBT with graded exposures and response prevention, plus cognitive therapy
  • Severe: May consider ECT or deep transcranial magnetic stimulation (TMS)

Medication

First Line

  • SSRIs (10–12 week trial; doses may exceed those for depression)
  • Fluoxetine, sertraline, fluvoxamine (FDA-approved for OCD)
  • Paroxetine (second-line due to side effects)
  • Children: Use age-appropriate dosing (see full context for ranges)
  • Precaution: Monitor for suicidal ideation, esp. in children/adolescents

Second Line

  • Switch to another SSRI or to TCA (clomipramine)
  • Clomipramine (Anafranil): Titrate up as tolerated, monitor ECG in older adults
  • Contraindications: recent MI, hypersensitivity, MAOI use, AV block, heart failure
  • Other agents:
  • SNRIs (venlafaxine), atypical antidepressants (mirtazapine)
  • Glutamatergic agents (N-acetylcysteine, memantine)
  • Adjunct: Antipsychotics (risperidone, aripiprazole) only for augmentation in treatment-resistant cases

Referral

  • For ERP, psychiatric evaluation if severe or interfering with functioning

Other Therapies

  • Deep TMS (FDA approved for OCD)
  • Neurosurgery (anterior cingulotomy, capsulotomy) for severe, refractory OCD

ONGOING CARE

  • Monitor: Y-BOCS to track progress; continue meds 1–2 years after remission, then taper slowly
  • High relapse risk if meds discontinued; chronic waxing/waning course
  • Suicidality: Up to 50% have suicidal thoughts

PATIENT EDUCATION

  • International OCD Foundation: https://iocdf.org/
  • Obsessive Compulsive Anonymous: http://obsessivecompulsiveanonymous.org

PROGNOSIS

  • Chronic, often partial improvement (25–60%)
  • Early onset: worse prognosis
  • Relapse is common after med discontinuation

COMPLICATIONS

  • Depression, anxiety, panic attacks
  • Avoidant behavior (school/work drop-out, homebound)

ICD-10 Codes

  • F42 Obsessive-compulsive disorder
  • F42.2 Mixed obsessional thoughts and acts
  • F42.3 Hoarding disorder

Clinical Pearls

  • ERP (CBT with graded exposure + response prevention) = first-line
  • Combine ERP with SSRI for moderate-to-severe OCD
  • Most patients respond to SSRI + ERP, but full remission is uncommon
  • Symptom improvement is often partial