Psychoneuroendocrinology
June 1, 2011
Tonya L Jacobs, Elissa S Epel, Jue Lin et al.
435 citations
After a 3-month meditation retreat with about 6 hours of daily practice, retreat participants showed greater telomerase activity—an indicator of cellular longevity—compared to a matched wait-list control group. Retreat participants also reported increased Perceived Control, Mindfulness, and Purpose in Life, and decreased Neuroticism. Statistical mediation analyses suggested that the retreat's effect on telomerase activity was explained by increases in Perceived Control and decreases in Neuroticism. These changes in perceived control and neuroticism were themselves partially explained by increased Mindfulness and Purpose in Life. Purpose in Life also directly mediated the group difference in telomerase activity, whereas Mindfulness did not. The findings suggest that meditation may influence cellular health through psychological changes.
Psychoneuroendocrinology
April 19, 2014
M. Kirkpatrick, Sunday M. Francis, Royce J. Lee et al.
106 citations
MDMA (ecstasy) increases feelings of sociability and closeness. This study tested whether those effects come from a rise in the hormone oxytocin. In 14 healthy MDMA users given MDMA, oxytocin nasal spray, or placebo, only the higher MDMA dose (1.5 mg/kg) raised blood oxytocin levels to a peak of 83.7 pg/ml around 90–120 minutes, versus 18.6 pg/ml after placebo. The higher oxytocin spray (40 IU) raised levels to 48.0 pg/ml. MDMA increased heart rate, blood pressure, and feelings of euphoria and sociability, but oxytocin spray did not. The subjective effects of MDMA were not linked to oxytocin levels, suggesting oxytocin may not be the main cause of MDMA's prosocial effects.
Psychoneuroendocrinology
December 1, 2023
Edem Ekpenyong Edem, Oluwatomisn Adeyosola Oguntala, Daniel Akinwale Ikuelogbon et al.
4 citations
Prolonged treatment with ketamine did not alleviate depressive-like behavior in female mice exposed to chronic unpredictable mild stress, but it did improve anxiety-like behaviors, short-term memory, and social interaction deficits. Ketamine also increased plasma oxytocin levels and oxytocin receptor expression while reducing nitro-oxidative stress markers in intestinal and hippocampal tissues. These results suggest that although short-term ketamine has antidepressant effects, its extended use does not adequately resolve depressive-like behavior in mice.
Psychoneuroendocrinology
July 1, 2025
Ece Idil, Bahar Yuksel, Zeynep Sen et al.
2 citations
Ketamine works faster as an antidepressant in females than in males, and this sex difference has been linked to ovarian hormones and faster metabolism in females. In adult female Wistar rats, blocking estrogen receptor alpha (ERα) with the antagonist MPP before a single antidepressant dose of ketamine did not prevent ketamine from reducing behavioral despair in the forced swim test. ERα antagonism and ketamine together showed a possible interaction on anxiety-like behaviors in the open field and elevated plus maze, but this effect was not statistically significant. Neither treatment affected fear memory. The results indicate that the sex-specific antidepressant effects of ketamine do not depend on ERα activity, though ERα may still influence anxiety-related brain circuits.