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 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
July 17, 2015
Oliver G. Bosch, Christoph Eisenegger, Jürg Gertsch et al.
42 citations
Gamma-hydroxybutyrate (GHB), a GHB-/GABAB-receptor agonist, produces euphoric, disinhibiting, and vitality-enhancing effects in healthy men. In a randomized, placebo-controlled crossover trial with 16 males, a single 20 mg/kg dose increased charitable donations and prosocial money distributions among participants who initially showed low prosociality. However, GHB did not alter emotion recognition, empathy, theory-of-mind, or basic cognitive functions. The drug raised plasma progesterone levels but left oxytocin, testosterone, cortisol, aldosterone, DHEA, and ACTH unchanged. These findings suggest that GHB's mood and prosocial effects may involve GHB-/GABAB-receptors and progesterone rather than typical social hormones like oxytocin or testosterone.
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.
Psychoneuroendocrinology
July 1, 2022
Katja Hoehne, Pascal Vrtička, Veronika Engert et al.
Oxytocin is released acutely in response to psychosocial stress, but a single session of Loving-kindness Meditation did not trigger acute oxytocin release. In a 9-month longitudinal study with 313 participants, three months of compassion-based mental training (Affect Module) reduced overall oxytocin levels during stress but increased overall oxytocin levels during Loving-kindness Meditation, compared to no training. These training-induced changes in overall oxytocin were unrelated to cortisol or subjective stress reactivity. The authors interpret the findings as alterations in the anticipated emotional relevance of events, suggesting oxytocin's role is allostatic rather than directly mediating stress reduction.
Psychoneuroendocrinology
January 1, 2020
H. Friedman, Douglas A. MacDonald, Nicholas J. L. Brown et al.
A reanalysis of data from a published paper claiming that loving-kindness meditation slows biological aging finds no compelling evidence for that claim. The original paper reported that telomere length decreased less in a loving-kindness meditation group than in a control group, with a mindfulness meditation group in between, but the reanalysis shows that the control group's telomere length decreased considerably over a very short time, a change unrelated to meditation. A 2×3 mixed factorial ANOVA found a significant repeated measures main effect but no significant interaction with condition, and one-way ANOVAs on pre-, post-, and change scores were non-significant. Effect sizes were consistently meager, and serious confounds existed, including control group members who meditated and unequal meditation time between the two meditation groups. The extraordinary claim lacks compelling evidence.
Psychoneuroendocrinology
October 1, 2019
Khoa D. Le Nguyen, Jue Lin, Sara B Algoe et al.
Loving-kindness meditation (LKM) may buffer the shortening of telomeres, the protective caps of chromosomes, while mindfulness meditation (MM) does not show the same protective effect. In a randomized trial with 142 midlife adults, telomere length decreased significantly in both the MM group and a waitlist control group over the study period, but not in the LKM group. The LKM group also experienced significantly less telomere attrition than the control group. The MM group's telomere changes fell between those of the LKM and control groups and were not significantly different from either. Self-reported emotions and practice duration or frequency did not explain the group differences. This work is the first to separate the effects of LKM and MM on telomere length.
Psychoneuroendocrinology
July 1, 2016
Joanna J Arch, Lauren N Landy, Kirk Warren Brown
Brief self-compassion meditation training dampens sympathetic and subjective anxiety responses to a social stress test. How well it works depends on certain baseline personality traits. People with lower non-attachment and higher social anxiety benefited less from the training, while those with lower social anxiety and lower non-attachment showed greater stress reduction. Trait self-compassion itself did not predict or moderate the training's effect. The findings highlight the importance of considering individual psychological traits in predicting responses to social evaluative threat, especially in the context of resiliency training.
Psychoneuroendocrinology
January 1, 2009
Thaddeus W W Pace, Lobsang Tenzin Negi, Daniel D Adame et al.
Training in compassion meditation for six weeks did not, on average, reduce stress-induced inflammation, cortisol, or distress compared to a health discussion control group. However, among those who meditated more, greater practice time was linked to smaller increases in the inflammatory marker interleukin-6 and lower self-reported distress after a standardized stress test. People who meditated above the median amount showed less stress reactivity than those who meditated less or were in the control group. The findings suggest that regularly engaging in compassion meditation may dampen immune and emotional responses to stress, but more research is needed to confirm this link.