What is the recommended treatment for a patient with Obsessive-Compulsive Disorder (OCD)?

Treatment of Obsessive-Compulsive Disorder

For mild-to-moderate OCD, initiate treatment with either an SSRI (sertraline 50-200 mg/day or fluoxetine 20-80 mg/day preferred) or cognitive-behavioral therapy with exposure and response prevention (CBT with ERP), while severe OCD or significant functional impairment requires combined treatment with both SSRI and CBT with ERP from the outset. 1

First-Line Treatment Selection

Mild-to-Moderate OCD

• Start with either SSRI monotherapy OR CBT with ERP alone 1
• CBT with ERP has a number needed to treat of 3 compared to 5 for SSRIs, making it slightly more effective as monotherapy 1
• SSRIs remain first-line medication choice based on efficacy, tolerability, safety profile, and absence of abuse potential 1

Severe OCD or Significant Functional Impairment

• Initiate combined treatment with both SSRI and CBT with ERP immediately, as combination treatment yields larger effect sizes than either monotherapy alone 1

SSRI Dosing Requirements

OCD requires substantially higher SSRI doses than depression or other anxiety disorders 1:

• Fluoxetine: 20-80 mg/day (FDA-approved range, start 20 mg/day and increase after several weeks if insufficient response) 2
• Sertraline: 50-200 mg/day (FDA-approved for OCD) 3
• Maintain maximum tolerated dose for 8-12 weeks minimum before determining treatment failure, as full therapeutic effect may be delayed 5 weeks or longer 1

The most common cause of apparent treatment resistance is inadequate SSRI doses or insufficient trial duration—never use less than 8-12 weeks at maximum tolerated dose 1.

Cognitive-Behavioral Therapy with ERP

• CBT with ERP is the evidence-based psychological treatment of choice, involving gradual, prolonged exposure to fear-provoking stimuli combined with instructions to abstain from compulsive behaviors 1
• Recommend 10-20 sessions of CBT with ERP 1
• Patient adherence to between-session homework (practicing ERP exercises) is the strongest predictor of treatment success—this must be emphasized to patients 1

Treatment-Resistant OCD Algorithm

After 12 weeks at maximum tolerated SSRI dose with inadequate response 1:

First-Line Augmentation

• Add an atypical antipsychotic (aripiprazole or risperidone have strongest evidence for OCD augmentation) 1
• However, a high-quality 2013 randomized trial demonstrated that adding EX/RP to SRIs was superior to adding risperidone (80% response rate for EX/RP vs 23% for risperidone vs 15% for placebo), with better tolerability 4

Alternative Augmentation Strategies

• Glutamatergic agents: N-acetylcysteine has the largest evidence base, with memantine as an alternative 1
• Switch to clomipramine if SSRIs have failed, though it is associated with more adverse events than SSRIs 5, 6

Severe Treatment-Resistant Cases

• FDA-approved deep repetitive transcranial magnetic stimulation (rTMS) for severe, treatment-resistant OCD 1

Long-Term Management

• Continue treatment for minimum 12-24 months after achieving remission before considering discontinuation 1
• Relapse risk is substantial with premature discontinuation—never stop medication before 12-24 months of remission 1
• Periodically reassess using standardized measures such as the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) 1

Critical Pitfalls to Avoid

• Never use inadequate SSRI doses or insufficient trial duration (less than 8-12 weeks at maximum tolerated dose)—this is the most common cause of apparent treatment resistance 1
• Do not prematurely discontinue medication before 12-24 months of remission 1
• Address family accommodation to OCD symptoms, as this can maintain or worsen the condition 1
• Emphasize homework compliance in CBT with ERP, as between-session practice is the strongest predictor of success 1