Is Seroquel (quetiapine) effective for treating obsessive-compulsive disorder (OCD)?

Quetiapine (Seroquel) for Obsessive-Compulsive Disorder

Quetiapine is not recommended as a first-line treatment for OCD but may be considered as an augmentation strategy for treatment-resistant cases that have failed to respond to SSRIs. 1

First-Line Treatment for OCD

The evidence-based approach to OCD treatment follows a clear hierarchy:

1. SSRIs as first-line pharmacotherapy

   • Medications with established efficacy include:
     • Sertraline (50-200 mg/day)
     • Fluoxetine (20-60 mg/day)
     • Fluvoxamine (may require twice-daily dosing) 1

2. Cognitive-behavioral therapy with exposure and response prevention (CBT-ERP)

   • Has larger effect sizes than pharmacological therapy
   • Can be used alone or in combination with medication 1

Role of Quetiapine in OCD Treatment

Quetiapine is not indicated as a primary treatment for OCD but may have a role in treatment-resistant cases:

• Small open-label studies show mixed results when quetiapine is used as an augmentation strategy:
  • One study reported 7 of 10 treatment-resistant OCD patients responded to quetiapine addition to SRIs with a 35.4% mean reduction in YBOCS scores 2
  • Another study found 31% response rate at one site but only 14% at another site with different patient characteristics 3
  • A small study using low-dose quetiapine (150 mg daily) found minimal efficacy with only 2 of 8 patients showing partial response 4

Augmentation Algorithm for Treatment-Resistant OCD

For patients who fail to respond adequately to SSRIs, consider the following augmentation strategies in order of evidence strength:

1. First consider other augmentation options with stronger evidence:

   • N-acetylcysteine has the largest evidence base as a glutamatergic agent
   • Memantine has demonstrated efficacy in several trials
   • Antipsychotic augmentation with risperidone or aripiprazole 1

2. If considering quetiapine augmentation:

   • Start at low doses (25 mg/day)
   • Gradually titrate up to 150-200 mg/day based on response and tolerability 3, 5
   • Evaluate response after 8-12 weeks of treatment
   • If beneficial, may maintain improvement over longer periods (6 months) 5

Clinical Considerations and Monitoring

• Treatment response in OCD typically begins by week 6, with maximal improvement by week 12 1
• Monitor for:
  • Common side effects of quetiapine including sedation, weight gain, and metabolic changes
  • Suicidal ideation, especially in the first months and after dose adjustments
  • Behavioral activation/agitation 1

Common Pitfalls

• Inadequate SSRI trial before augmentation: Ensure patients have received adequate doses of SSRIs for at least 8-12 weeks before considering quetiapine augmentation 1
• Insufficient dose or duration: Treatment should continue for at least 8-12 weeks at maximum tolerated dose to determine efficacy 1
• Failure to recognize partial response: Some patients may benefit from continued treatment even with partial initial response 1
• Patient selection: Quetiapine augmentation appears less effective in patients with hoarding symptoms 3

In summary, while quetiapine may benefit some treatment-resistant OCD patients as an augmentation strategy, it should not be considered before optimizing SSRI treatment and exploring other augmentation strategies with stronger evidence bases.