Ketamine Korner: Edition 11
Ketamine Korner is a bi-weekly newsletter exploring advances in ketamine therapy, originally started by Mind Pain Relief Institute Co-Founder Dr. Rohit Aiyer.
Each edition is republished with permission from Dr. Aiyer.
Latest Research Highlight:
Research Update: Concerns about cognitive side effects are common when patients consider ketamine treatment, particularly given its anesthetic and dissociative properties. However, controlled clinical data provide a more nuanced picture.
A large open-label, long-term safety study (SUSTAIN-2, Wajs et al., Journal of Clinical Psychiatry, 2020) followed patients receiving intranasal esketamine for up to one year. The study found no evidence of progressive or clinically meaningful cognitive decline over time, with performance across domains such as attention, memory, and executive function remaining stable.
Similarly, a systematic review published in Frontiers in Neuroscience (Marchi et al., 2022) evaluated ketamine’s effects on cognition across multiple studies. The authors concluded that short-term cognitive changes (such as mild dissociation or attention shifts) may occur during or shortly after administration, but there is no consistent evidence of lasting cognitive impairment in controlled therapeutic settings.
In contrast, it is important to distinguish these findings from data on chronic, high-frequency recreational ketamine use, where cognitive impairment—particularly in memory—has been documented. Clinical protocols differ significantly in dose, frequency, and supervision.
A Brief History of Ketamine and Cognitive Concerns:
Early Anesthetic Use: Ketamine has been used safely in anesthesia for decades, including in pediatric populations, with a well-characterized short-term cognitive and perceptual profile.
Emergence in Psychiatry: As ketamine entered psychiatric use in the 2000s, attention shifted to its rapid antidepressant effects—but also to concerns about dissociation and potential neurotoxicity.
Distinguishing Clinical vs Non-Clinical Use: By the 2010s, research began clearly separating supervised, intermittent clinical dosing from frequent, unsupervised use, which carries different risk profiles.
Current Perspective: Today, the consensus is that ketamine—when used in structured, medically supervised settings—does not appear to cause progressive cognitive decline, though ongoing research continues to monitor longer-term outcomes.
Mythbuster:
Myth: Ketamine treatment causes long-term brain damage or memory loss.
Reality:
Clinical studies do not show progressive or clinically meaningful cognitive decline with medically supervised ketamine or esketamine use (Wajs et al., 2020).
Short-term cognitive effects can occur, including dissociation or temporary attention changes, but these typically resolve within hours.
Risk depends heavily on context—patterns seen in recreational misuse do not reflect controlled medical protocols.
Ketamine is not cognitively “neutral” in the moment—but current evidence suggests it is cognitively safe over time when used appropriately.
Key Takeaway:
Ketamine’s cognitive effects are often misunderstood. While transient changes can occur during treatment, the best available evidence suggests that long-term cognitive function remains stable under clinical care.
As ketamine therapy becomes more widely used, distinguishing between evidence-based treatment and misconceptions drawn from non-medical use is critical.
As the science evolves, so does our understanding of ketamine’s safety profile. Staying informed allows patients and clinicians to make decisions grounded in evidence, not fear.
Until next time, stay curious and engaged with the possibilities ahead.