Is buspirone a good augmenting agent for an adult patient with partial response to 200mg sertraline (Selective Serotonin Reuptake Inhibitor) for Major Depressive Disorder (MDD), Generalized Anxiety Disorder (GAD), and Obsessive-Compulsive Disorder (OCD)?

Buspirone Augmentation for Partial Response to Sertraline

Buspirone is not a good augmenting agent for this patient with partial response to 200mg sertraline for MDD, GAD, and OCD. Instead, augmentation with cognitive behavioral therapy (CBT) with exposure and response prevention (ERP) should be the first-line approach, or bupropion if CBT is unavailable 1.

Evidence Against Buspirone Augmentation

For Major Depressive Disorder

• Bupropion is superior to buspirone for augmentation of SSRIs in MDD, with low-quality evidence showing that while response and remission rates are similar, bupropion decreases depression severity significantly more than buspirone 2.
• Moderate-quality evidence demonstrates that discontinuation due to adverse events is significantly lower with bupropion (12.5%) compared to buspirone (20.6%) when augmenting citalopram, indicating better tolerability 2, 3.

For Obsessive-Compulsive Disorder

• Buspirone has no efficacy for OCD augmentation, with controlled trial evidence showing that adding buspirone to fluvoxamine (another SSRI) was no better than placebo in reducing obsessive-compulsive symptoms in treatment-refractory patients 4.
• Current OCD guidelines do not recommend buspirone as an augmentation strategy, instead prioritizing antipsychotics (risperidone, aripiprazole), clomipramine, or glutamatergic agents (N-acetylcysteine, memantine) for SSRI-resistant OCD 2.

For Generalized Anxiety Disorder

• While buspirone is FDA-approved for GAD as monotherapy 5, 6, 7, there is no evidence supporting its use as an augmentation agent to SSRIs for GAD 6, 8.
• Studies examining buspirone combined with psychological therapy for GAD showed no advantage over placebo, with higher dropout rates in the buspirone group 8.

Recommended Treatment Algorithm

First-Line: CBT Augmentation

• Add CBT with ERP protocol (10-20 sessions) while continuing sertraline 200mg, which addresses all three conditions (MDD, OCD, and GAD) simultaneously 1.
• CBT augmentation has lower discontinuation rates due to adverse effects compared to pharmacological augmentation and provides sustained long-term benefits 1.
• Monitor response over 8-12 weeks while CBT is ongoing 1.

Second-Line: Bupropion Augmentation

• If CBT is unavailable or declined, add bupropion 150mg/day as pharmacological augmentation 1, 3.
• Bupropion shows decreased depression severity with lower adverse effect discontinuation compared to buspirone when augmenting SSRIs 2, 3.

Third-Line: OCD-Specific Augmentation

• If OCD symptoms remain the primary concern despite CBT, consider antipsychotic augmentation (risperidone or aripiprazole) or glutamatergic agents (N-acetylcysteine or memantine) 2.

Critical Clinical Considerations

Why Not Buspirone?

• No evidence of efficacy for OCD, the most treatment-resistant condition in this patient's presentation 4.
• Inferior to bupropion for MDD augmentation in both efficacy and tolerability 2.
• Higher discontinuation rates due to adverse events compared to alternative augmentation strategies 2.

Why Augmentation Over Switching?

• The patient has achieved partial response, and augmentation strategies obtain faster response than switching compounds 1.
• Sertraline is already at maximum dose (200mg), making dose escalation not an option 1.
• Switching to another SSRI offers no mechanistic advantage and risks losing current gains 1.

Safety Monitoring

• Monitor for serotonin syndrome if adding any pharmacological augmentation, particularly in the first 24-48 hours 1.
• All antidepressants carry black box warnings for increased suicidal thinking, requiring close monitoring especially during treatment transitions 1.
• Buspirone may interfere with urinary metanephrine/catecholamine assays and should be discontinued 48 hours prior to testing for pheochromocytoma 5.