Obsessive-Compulsive Disorder (OCD) Clinical Overview
I. The "On-Call" Snapshot
Clinical Significance in Malaysia
OCD is a common "hidden" diagnosis. It's highly debilitating and frequently co-exists with Major Depressive Disorder (MDD) and other anxiety disorders. Your job as a House Officer is to screen for it in high-risk patients (e.g., severe anxiety, depression, dermatitis of the hands) and initiate safe first-line management before referring to Psychiatry.
High-Yield Definition
OCD is a psychiatric disorder characterised by the presence of:
Obsessions: Recurrent, persistent, and intrusive thoughts, urges, or images that are experienced as unwanted and cause marked anxiety or distress.
Compulsions: Repetitive behaviours (e.g., washing, checking) or mental acts (e.g., praying, counting) that the individual feels driven to perform in response to an obsession or according to rigid rules, aimed at preventing or reducing anxiety (but are not realistically connected).
Clinical One-Liner
"Intrusive, unwanted thoughts that cause severe anxiety, which the patient tries to neutralise with repetitive, ritualistic actions they know are excessive."
II. Etiology & Risk Factors
Etiology
Multifactorial. The dominant theory is dysregulation of the cortico-striato-thalamo-cortical (CSTC) circuits, leading to a "stuck loop" of error detection. There is a strong genetic component and a clear link to serotonin dysregulation.
Risk Factors
Genetic: First-degree relative with OCD.
Neurological: Paediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS) - look for sudden onset in children.
Environmental: Childhood trauma and significant life stressors can precipitate onset.
Comorbidities: High association with tic disorders (Tourette's), MDD, and other anxiety disorders.
III. Quick Pathophysiology
Think of it as a faulty "brain alarm system."
The Orbitofrontal Cortex (OFC) and Anterior Cingulate Cortex (ACC) (your "error detectors") become hyperactive, firing a constant "something is wrong!" signal (e.g., "my hands are contaminated").
The Caudate Nucleus (part of the striatum, your "filter") fails to suppress this signal.
The signal loops via the Thalamus back to the cortex, creating a self-perpetuating circuit of anxiety.
The compulsion (e.g., handwashing) is a learned, desperate behavioural attempt to "turn off" the alarm and reduce the anxiety. Serotonin (5-HT) is the key modulator in this circuit, which is why SSRIs work.
IV. Classification
The primary classification is via DSM-5 diagnostic criteria.
The most clinically relevant specifier is Insight:
With Good or Fair Insight: The patient recognises that the OCD beliefs are definitely or probably not true. (This is the majority).
With Poor Insight: The patient thinks the OCD beliefs are probably true.
With Absent Insight / Delusional Beliefs: The patient is completely convinced the OCD beliefs are true. This is critical as it borders on psychosis and requires antipsychotic augmentation.
V. Clinical Assessment
🚩 Red Flags & Immediate Actions
Active Suicidal Ideation: High rates of SI due to the distressing and "torturous" nature of the obsessions.
Action: Immediate psychiatric referral, consider admission. Conduct a full suicide risk assessment.
Severe Self-Neglect or Harm: Patient cannot eat, drink, or leave the house due to rituals (e.g., contamination fears, checking rituals > 8 hours/day). Skin is severely excoriated or infected from washing.
Action: Medical admission for stabilisation (e.g., IV fluids, wound care) + urgent psychiatric consult.
Absent Insight / Delusional Beliefs: Patient is convinced their fear is real (e.g., "I know my family will die if I don't tap the wall").
Action: Urgent psychiatric referral. Do not challenge the delusion. These patients require antipsychotics.
History
Key Diagnostic Clues (Pathognomonic/Classic Presentations)
Ask directly, patients will not volunteer this:
"Do you ever have thoughts that get 'stuck' in your head, even though you don't want them?"
"Do you feel driven to do things over and over again, like washing, checking, or counting, to feel less anxious?"
Ego-dystonic nature: The key is that the patient is distressed by their thoughts and wishes they would stop (vs. OCPD, who think their way is the "right" way).
Time: Ask how much time they spend on rituals. Diagnosis requires >1 hour/day or significant functional impairment.
Symptom Breakdown by "Flavour"
Contamination Obsessions + Washing/Cleaning Compulsions: (Most common). Fear of germs, dirt, bodily fluids.
Doubting Obsessions + Checking Compulsions: Fear of harm (e.g., "Did I lock the door?", "Did I turn off the stove?"). Leads to repetitive checking.
Symmetry/Ordering Obsessions + Arranging/Counting Compulsions: A persistent feeling of things being "not right," "unbalanced." Must arrange items until it "feels right."
Unacceptable/Taboo Thoughts + Mental Compulsions: Intrusive sexual, religious, or violent thoughts (e.g., fear of harming a loved one). Compulsions are often mental (e.g., praying, counting, "undoing" a bad thought with a good one).
Pertinent Negatives
No pleasure from compulsions: This is not an addiction. The act is done to reduce anxiety, not for pleasure.
Thoughts are their own: Patient does not believe thoughts are being inserted into their head by an external force (this would be psychosis).
Not real-life worries: Obsessions are distinct from the excessive worry in Generalized Anxiety Disorder (GAD), which focuses on real-life problems (e.g., finances, exams).
Physical Examination (OSCE Approach)
General Inspection
Often unremarkable.
May see signs of anxiety: psychomotor agitation, fidgeting, poor eye contact, tremor.
May appear dishevelled (if severe self-neglect) or meticulously groomed.
Vitals
Can be normal. Tachycardia or hypertension if acutely anxious or having a panic attack.
Disease-Specific Examination (System-based)
Dermatology: Look at the hands. You may see classic irritant contact dermatitis: dry, erythematous, lichenified, or raw/bleeding skin from excessive washing with harsh soaps.
Mental State Examination (MSE):
Appearance & Behaviour: See "General Inspection." May observe rituals during the interview (e.g., tapping, re-arranging items).
Mood: Often "anxious," "distressed," "fed up," "depressed."
Thought (Content): This is the core. Probe for obsessions. Assess for suicidal ideation. Assess for delusions.
Thought (Possession): Confirm thoughts are not perceived as external (i.e., not thought insertion).
Perception: Usually no hallucinations.
Cognition: Intact.
Insight: This is the most important part. Assess on a spectrum from "Good" to "Absent/Delusional" (see Section IV).
Examination for Differentials
Look for signs of tic disorders (e.g., motor/vocal tics) as tic-related OCD is a specific subtype.
Look for skin picking (excoriation disorder) or hair-pulling (trichotillomania), which are OCD-related disorders.
Clinical Pearl
The line between an anxious personality and OCD is distress and function. The line between OCD and Obsessive-Compulsive Personality Disorder (OCPD) is ego-syntonic vs. ego-dystonic.
OCD (Ego-dystonic): "I hate these thoughts and rituals, they're illogical and torturing me."
OCPD (Ego-syntonic): "My way of being perfect and organised is the correct way. Other people are just sloppy."
VI. Diagnostic Workflow
Differential Diagnosis
1. Generalized Anxiety Disorder (GAD)
Points For: High anxiety, worry, physical symptoms of anxiety.
Points Against: GAD worry is about real-life concerns (finances, work, health). OCD obsessions are ego-dystonic, often bizarre, and linked to specific compulsions.
How to Differentiate: Ask for the content of the worry.
2. Major Depressive Disorder (MDD)
Points For: Highly comorbid (~50%). Low mood, anhedonia, fatigue.
Points Against: MDD features ruminations (past-focused, "I am worthless") which are mood-congruent. OCD obsessions are intrusive and anxiety-provoking.
How to Differentiate: Ask which came first. Often, the depression is a result of the functional impairment and distress from OCD.
3. Obsessive-Compulsive Personality Disorder (OCPD)
Points For: Perfectionism, rigidity, preoccupation with rules and order.
Points Against: OCPD is ego-syntonic. The person sees their traits as positive and correct. They lack true obsessions/compulsions.
How to Differentiate: Ask: "Are you distressed by your thoughts/habits?" OCPD distresses others; OCD distresses the patient.
4. Psychotic Disorders (e.g., Schizophrenia)
Points For: Bizarre thoughts.
Points Against: In OCD (with insight), the patient knows the thoughts are from their own mind. In psychosis, there may be thought insertion, formal thought disorder, or other delusions/hallucinations.
How to Differentiate: A full MSE. This is why assessing insight (delusional vs. not) is critical.
Investigations Plan
Bedside / Initial (First 15 Mins)
Mental State Examination (MSE): This is your primary diagnostic tool.
Y-BOCS (Yale-Brown Obsessive Compulsive Scale): The gold standard for assessing severity. You can use a quick screener version. Ask about time spent, distress, and interference.
First-Line Labs & Imaging
Not for diagnosis, but to rule out organic causes if presentation is atypical (e.g., new, sudden onset in an older adult).
Bloods: FBC, RP, LFTs, TFTs (hyperthyroidism can mimic anxiety), Glucose.
Urine: Urine drug screen (stimulants can cause anxiety/compulsive behaviours).
Confirmatory / Gold Standard
Clinical Diagnosis based on DSM-5 criteria (history and MSE).
Y-BOCS to formally stage severity.
VII. Staging & Severity Assessment
We use the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). It's a 10-item scale that quantifies severity based on time spent, interference, and distress from obsessions and compulsions.
Score 0-7: Subclinical
Score 8-15: Mild
Score 16-23: Moderate
Score 24-31: Severe
Score 32-40: Extreme
Impact on Management:
Mild: Psychotherapy (CBT/ERP) alone may be sufficient.
Moderate-Severe: SSRI + CBT/ERP is first-line.
Extreme/Refractory: Higher SSRI doses, Clomipramine, or augmentation.
VIII. Management Plan
A. Principle of Management
Pharmaco: Modulate the serotonin system (CSTC circuit).
Psycho: Break the learned link between the obsession (anxiety) and the compulsion (relief) via Exposure and Response Prevention (ERP).
Manage comorbidities (MDD, anxiety) and ensure safety.
B. Immediate Stabilisation (The ABCDE Plan)
This is for the "Red Flag" patient.
A/B/C: Usually stable unless there's a serious self-harm attempt.
D (Disability/Neurology):
If severe agitation/panic: Give a short-term benzodiazepine (e.g., Diazepam 5mg STAT, use with caution).
If suicidal: One-to-one nursing, remove ligature risks, urgent psychiatric consult.
If psychotic (delusional insight): Urgent psychiatric consult, may need STAT antipsychotic (e.g., Haloperidol 5mg IM).
E (Exposure): Manage any physical complications (e.g., wound care for dermatitis, rehydration for self-neglect).
C. Definitive Treatment (The Ward Round Plan)
This is a combined approach.
1. Pharmacotherapy (Start this in MOPD/Ward)
First-Line: SSRIs
Rule: Start low, go slow, but aim for higher doses than used in depression.
Rule: A trial must be for 10-12 weeks at the maximum tolerated dose before calling it a failure.
Options (per Malaysian formulary):
Fluoxetine: Start 20mg OD, titrate up to 40-80mg OD.
Sertraline: Start 50mg OD, titrate up to 100-200mg OD.
Fluvoxamine: Start 50mg OD, titrate up to 100-300mg/day (often needs BD dosing).
Second-Line:
Switch to a different SSRI.
Switch to Clomipramine (TCA): Very effective, but more side effects (anticholinergic, cardiotoxicity). Start 25mg ON, titrate to 100-250mg/day. Must get baseline ECG.
Refractory / Augmentation:
This is specialist-level. Refer to Psychiatry.
Options: Augment SSRI with a low-dose antipsychotic (e.g., Risperidone 0.5-2mg ON, Aripiprazole).
2. Psychotherapy (Refer for this)
Gold Standard: Cognitive Behavioural Therapy (CBT) with Exposure and Response Prevention (ERP).
How it works:
Exposure: The therapist guides the patient to intentionally trigger their obsession (e.g., touch a "contaminated" doorknob).
Response Prevention: The patient is coached to resist performing the compulsion (e.g., not wash their hands) for a set time.
Result: The anxiety spikes, then plateaus, then naturally habituates (decreases). The brain learns the catastrophic outcome doesn't happen, and the obsession-compulsion link is broken.
D. Long-Term & Discharge Plan
Referral: All new OCD diagnoses must be referred to the Psychiatry Clinic for follow-up and to Clinical Psychology for formal ERP.
Medication: Continue SSRI for at least 1-2 years after remission, then consider a very slow taper. Relapse rates are high if stopped early.
Psychoeducation: Advise patient and family that it's a chronic, relapsing-remitting illness, like asthma or diabetes. Management is about control, not necessarily a "cure."
IX. Complications
Immediate: Suicidality, severe panic attacks.
Short-Term: Social withdrawal, family/relationship conflict, occupational/academic failure.
Long-Term:
Psychiatric: High risk of developing MDD (Major Depressive Disorder), other anxiety disorders, or Substance Use Disorder.
Physical: Severe irritant contact dermatitis, skin infections, dental problems (if rituals involve brushing).
X. Prognosis
Chronic, waxing-and-waning course.
With treatment (SSRI + ERP), ~70% of patients have a good response (significant symptom reduction).
Poor Prognostic Factors: Early age of onset, severe symptoms, poor insight (delusional), co-morbid personality disorder (especially OCPD), family accommodation of rituals.
XI. How to Present to Your Senior
Use the SBAR format.
(S) Situation: "Dr, I'm referring Mr. A, a 30-year-old man from MOPD, whom I've diagnosed with new-onset OCD."
(B) Background: "He presented with 1-year history of worsening anxiety. On direct questioning, he admits to intrusive thoughts about contamination and spends >4 hours/day washing his hands. He lost his job as a clerk. No other psych history, no substance use. No SI."
(A) Assessment: "My assessment is severe OCD (Y-BOCS ~28) with good insight. His hands show severe dermatitis. My main differentials (MDD, GAD) are less likely as the obsessions are primary. Bloods are unremarkable."
(R) Recommendation: "I have started him on Fluoxetine 20mg OD, given 1 week of Diazepam 2mg ON for severe anxiety, provided aqueous cream for his hands, and referred him to the Psych Clinic and Clinical Psychology. Is this plan acceptable?"
XII. Summary & Further Reading
Top 3 Takeaways
Ask, Don't Wait: Patients are ashamed. You must screen for obsessions and compulsions in any patient with severe anxiety, depression, or dermatitis.
OCD ≠ OCPD: OCD is ego-dystonic (distressing to patient). OCPD is ego-syntonic (patient thinks their way is right).
Treatment = SSRI + ERP: First-line is high-dose SSRIs for 10-12 weeks plus referral for CBT with Exposure and Response Prevention.
Key Resources
UpToDate: "Obsessive-compulsive disorder in adults: Epidemiology, pathogenesis, clinical manifestations, course, and diagnosis"
UpToDate: "Treatment of obsessive-compulsive disorder in adults"
Amboss: "Obsessive-compulsive disorder"
Key Review Article: Goodman, W. K., et al. (2020). Obsessive-compulsive disorder. New England Journal of Medicine, 382(26), 2530-2542.
