Obsessive-Compulsive Disorder

Definition & Epidemiology - Mind's Endless Loop

• Obsessions: Recurrent, persistent, intrusive, unwanted thoughts, urges, or images causing significant anxiety or distress.
• Compulsions: Repetitive behaviors (e.g., hand washing) or mental acts (e.g., counting) performed to neutralize obsessions or reduce distress; often excessive or not realistically connected.
• Core Cycle: Obsession → Anxiety → Compulsion → Temporary Relief.
• Epidemiology:
  • Lifetime prevalence: 2-3%.
  • Common Age of Onset: Adolescence/early adulthood.

    ⭐ OCD has a bimodal age of onset, with peaks in early adolescence and early adulthood.

  • Gender Distribution: Adults M=F; Childhood M>F.

Clinical Features - Ritual Realm Rules

Obsessions: recurrent, persistent thoughts/urges/images. Compulsions: repetitive behaviors/mental acts responding to obsessions.

• Common Patterns:

  Obsessions (Thoughts/Urges)	Compulsions (Behaviors/Mental Acts)
  Contamination (germs, dirt)	Washing/Cleaning (hands, objects)
  Pathological Doubt (uncertainty)	Checking (locks, appliances)
  Symmetry/Exactness (order)	Ordering/Arranging (items precisely)
  Aggressive/Horrific Thoughts (harm)	Mental Rituals (praying, counting silently)
  Unwanted Sexual Thoughts	Repeating Actions (touching, tapping)

• 📌 Mnemonic for obsessions: 'Can't Stop Doubting Harm' (Contamination, Symmetry, Doubt, Harm/Aggression).
• Specifiers:
  • Insight: Good/fair, poor, absent/delusional.
  • Tic-related: Current/past tic disorder.

⭐ The most common pattern is contamination obsessions with cleaning compulsions.

Etiology & Pathophysiology - Circuit Overload

• Neurobiological Factors:
  • Serotonin (5-HT) dysregulation: Implicated as a key neurotransmitter.
  • CSTC Circuit Hyperactivity: Overactivity in Cortico-Striato-Thalamo-Cortical loops.
    • Key areas: Orbitofrontal Cortex (OFC), Anterior Cingulate Cortex (ACC), and Striatum.
    • 

  ⭐ Dysfunction in the Cortico-Striato-Thalamo-Cortical (CSTC) pathways is a key neurobiological finding in OCD.

• Genetic Factors:
  • ↑ Monozygotic twin concordance suggests genetic link.
  • Family history is a significant risk factor.
• PANDAS:
  • Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections; linked to childhood OCD onset.
• Psychological Theories:
  • Cognitive: e.g., inflated responsibility, thought-action fusion.
  • Behavioral: e.g., Mowrer's two-factor theory (classical & operant conditioning).

Diagnosis & DDx - Detective's Toolkit

• DSM-5 Criteria:

  • Presence of obsessions, compulsions, or both.
  • Time-consuming (>1 hr/day) OR cause significant distress/impairment.
  • Not attributable to substance/medical condition.
  • Not better explained by another mental disorder.

• Assessment: Y-BOCS (Gold Standard severity):

  • 0-7 Subclinical, 8-15 Mild, 16-23 Moderate, 24-31 Severe, 32-40 Extreme.

• DDx:

  • Anxiety (GAD), Depression.
  • OCPD (vs. OCD's ego-dystonia).
  • Psychosis.
  • BDD, Hoarding, Trichotillomania, Excoriation.

⭐ OCD is ego-dystonic, meaning individuals perceive their obsessions/compulsions as intrusive and unwanted, unlike OCPD traits which are ego-syntonic.

Management - Freedom Fighters

• Pharmacotherapy:
  • First-line: SSRIs (e.g., Fluoxetine, Fluvoxamine, Sertraline) at higher doses & longer duration than depression (trial 8-12 weeks).
  • Second-line/SSRI non-responders: Clomipramine (TCA) - highly effective.
  • Augmentation (treatment resistance): Antipsychotics (e.g., Risperidone), Memantine (investigational).
• Psychotherapy:
  • Cognitive Behavioral Therapy (CBT) with Exposure and Response Prevention (ERP) is gold standard.

  ⭐ Exposure and Response Prevention (ERP) is the most effective form of psychotherapy for OCD, often used in conjunction with SSRIs.

• Other Treatments (Refractory OCD):
  • Deep Brain Stimulation (DBS), Transcranial Magnetic Stimulation (TMS).
• 📌 Mnemonic: 'Effective OCD Meds: Some People Choose CBT First' (SSRIs, Psychotherapy/ERP, Clomipramine, CBT, Fluvoxamine).

High‑Yield Points - ⚡ Biggest Takeaways

• OCD features ego-dystonic obsessions (intrusive thoughts) and compulsions (repetitive acts).
• Common obsessions: contamination, doubt, symmetry; Compulsions: washing, checking, ordering.
• Compulsions aim to reduce distress from obsessions; often not realistically linked to feared event.
• Serotonin dysregulation is a key neurobiological factor.
• Treatment: SSRIs (high dose, long duration) and Exposure and Response Prevention (ERP) are first-line.
• Consider PANDAS for acute childhood onset; Y-BOCS assesses severity_._