Question 1

Is buspirone effective as a standalone anxiolytic, or only as an add-on to SSRIs?

Accepted Answer

Buspirone is a 5-HT1A partial agonist with modest efficacy as monotherapy (effect size d = 0.17, the lowest of any medication class studied in the Hidalgo et al. 2007 meta-analysis), FDA-approved for GAD but often prescribed at subtherapeutic doses (10-15 mg). Therapeutic range is 20-45 mg/day. Counter-intuitively, monotherapy evidence is more robust than augmentation evidence: two double-blind RCTs of buspirone augmentation for SSRI nonresponders failed to separate from placebo. STAR*D (depression trial) showed buspirone augmentation comparable to bupropion augmentation. Woo et al. 2025 (open-label) showed HAM-A reduction from 25.2 to 15.4 in anxious depression. Monotherapy is reasonable for mild anxiety, substance-use patients (no dependence risk), or patients declining SSRI side effects. As augmentation, expectations should be conservative.

Question 2

What's buspirone's effect size as monotherapy?

Accepted Answer

Buspirone is a 5-HT1A partial agonist with modest efficacy as monotherapy (effect size d = 0.17, the lowest of any medication class studied in the Hidalgo et al. 2007 meta-analysis), FDA-approved for GAD but often prescribed at subtherapeutic doses (10-15 mg). Therapeutic range is 20-45 mg/day. Counter-intuitively, monotherapy evidence is more robust than augmentation evidence: two double-blind RCTs of buspirone augmentation for SSRI nonresponders failed to separate from placebo. STAR*D (depression trial) showed buspirone augmentation comparable to bupropion augmentation. Woo et al. 2025 (open-label) showed HAM-A reduction from 25.2 to 15.4 in anxious depression. Monotherapy is reasonable for mild anxiety, substance-use patients (no dependence risk), or patients declining SSRI side effects. As augmentation, expectations should be conservative.

Question 3

How much does buspirone augmentation improve SSRI response?

Accepted Answer

Buspirone is a 5-HT1A partial agonist with modest efficacy as monotherapy (effect size d = 0.17, the lowest of any medication class studied in the Hidalgo et al. 2007 meta-analysis), FDA-approved for GAD but often prescribed at subtherapeutic doses (10-15 mg). Therapeutic range is 20-45 mg/day. Counter-intuitively, monotherapy evidence is more robust than augmentation evidence: two double-blind RCTs of buspirone augmentation for SSRI nonresponders failed to separate from placebo. STAR*D (depression trial) showed buspirone augmentation comparable to bupropion augmentation. Woo et al. 2025 (open-label) showed HAM-A reduction from 25.2 to 15.4 in anxious depression. Monotherapy is reasonable for mild anxiety, substance-use patients (no dependence risk), or patients declining SSRI side effects. As augmentation, expectations should be conservative.

Question 4

Why is buspirone not useful for acute anxiety?

Accepted Answer

Buspirone is a 5-HT1A partial agonist with modest efficacy as monotherapy (effect size d = 0.17, the lowest of any medication class studied in the Hidalgo et al. 2007 meta-analysis), FDA-approved for GAD but often prescribed at subtherapeutic doses (10-15 mg). Therapeutic range is 20-45 mg/day. Counter-intuitively, monotherapy evidence is more robust than augmentation evidence: two double-blind RCTs of buspirone augmentation for SSRI nonresponders failed to separate from placebo. STAR*D (depression trial) showed buspirone augmentation comparable to bupropion augmentation. Woo et al. 2025 (open-label) showed HAM-A reduction from 25.2 to 15.4 in anxious depression. Monotherapy is reasonable for mild anxiety, substance-use patients (no dependence risk), or patients declining SSRI side effects. As augmentation, expectations should be conservative.

PsychHQ

Buspirone: Efficacy as Monotherapy vs Augmentation for SSRI-Resistant Anxiety