Bipolar depression creates an agonizing clinical trap: patients are paralyzed by severe lows, yet traditional antidepressants take weeks to work and carry the terrifying risk of an “affective switch”—triggering a manic episode or rapid cycling. In Episode 55, we explore a 2026 review by Queissner and colleagues showing how ketamine and esketamine rewrite the rules by bypassing serotonin and targeting the brain’s glutamate “gas pedal”.

We unpack the staggering data: an odds ratio of 10.68 for rapid relief, with the REAL-ESK study showing zero cases of manic switching in real-world patients using intranasal esketamine. The episode dives deep into the biology, exploring Rizzo’s 2025 discovery of ketamine’s dual mechanism (NMDA and mu-opioid receptor modulation) that specifically targets anhedonia by restoring dopamine to the brain’s reward cen ...