Ketamine

A new clinical trial suggests that esketamine nasal spray, used alone without oral antidepressants, may reduce depressive symptoms in patients with treatment-resistant depression. The fast-acting treatment showed benefits within 24 hours and sustained effects over four weeks.

Ketamine’s popularity is surging in both medical and recreational circles, but so are its risks. A new international survey of people addicted to the drug sheds light on severe health effects, treatment shortcomings, and the urgent need for better care.

Researchers believe the antidepressant esketamine may "reset" rigid brain circuits. A new study provides evidence for this, showing the drug increases brain excitability while reducing top-down control, a state of cortical disinhibition thought to alleviate depressive symptoms.

Researchers have discovered that psilocybin—but not ketamine—triggers widespread changes in neuropeptide-related genes in the rat hypothalamus. These findings may help explain how psychedelics influence mood, appetite, and stress responses through deep brain systems.

New research shows a single low, non-anesthetic dose of ketamine revived pleasure seeking in chronically stressed mice by restoring weakened excitatory synapses onto nucleus accumbens dopamine D1 neurons, pinpointing a circuit mechanism for the drug’s rapid antidepressant effect.

New research suggests that hormones linked to the body’s stress response do not influence how people with treatment-resistant depression respond to ketamine. However, lower hormone levels were associated with longer depressive episodes, pointing to possible biomarkers for depression duration.

A new study suggests chronic opioid use may interfere with the brain’s natural ability to respond to placebo antidepressants. Surprisingly, ketamine’s antidepressant effects remained intact—raising intriguing questions about how drugs, expectations, and mood-regulating systems interact.

Ketamine therapy, when combined with psychedelic-inspired support, shows strong potential for reducing PTSD symptoms in those who haven’t responded to conventional treatments, new research suggests.

A 44-year-old man with alcoholism, depression, and antisocial personality traits underwent three years of ketamine-assisted psychotherapy, resulting in reduced alcohol use, depression, and violent thoughts.

A small, preliminary study suggests that a single intramuscular ketamine injection may rapidly ease symptoms in patients with treatment-resistant obsessive-compulsive disorder.

A study found that levodopa-induced dyskinesia disconnects the motor cortex from movement control, allowing abnormal movements. Ketamine reduced these movements, restored some brain control, and altered neural interactions, showing promise as a potential treatment.

Ketamine infusion induces feelings of awe, which may mediate its antidepressant effects. Stronger awe experiences were linked to greater, longer-lasting depression symptom improvements, independent of dissociative symptoms

Researchers found that ketamine reduces "giving up" behavior in zebrafish by altering astrocyte activity, suggesting its antidepressant effects involve non-neuronal brain cells and promoting resilience against futility-induced passivity.

A study found that ketamine, which causes dissociation, did not increase emotional suppression in PTSD patients. Instead, it decreased brain connectivity involved in emotion regulation.

Researchers found that ketamine blurs the brain’s ability to distinguish between self- and other-produced touch, particularly in a brain area involved in social processing.