Rationale: Endogenous opioids inhibit nociceptive processing and promote the experience of pleasure. It has been proposed that pain and pleasure lie at opposite ends of an affective spectrum, but the relationship between pain and pleasure and the role of opioids in mediating this relationship has not been tested.
Objectives: Here, we used obese individuals as a model of a dysfunctional opioid system to assess the role of the endogenous opioid peptide, beta-endorphin, on pain and pleasure sensitivity.
Methods: Obese (10M/10F) and age- and gender-matched non-obese (10M/10F) controls were included in the study. Pain sensitivity using threshold, tolerance, and subjective rating assessments and perceived sweet pleasantness using sucrose solutions were assessed in two testing sessions with placebo or the opioid antagonist, naltrexone (0.7 mg/kg body weight). Beta-endorphin levels were assessed in both sessions.
Results And Conclusions: Despite having higher levels of baseline beta-endorphin and altered beta-endorphin-reactivity to naltrexone, obese individuals reported a similar increase in pain and decrease in pleasantness following naltrexone compared to non-obese individuals. Beta-endorphin levels did not correlate with pain or pleasantness in either group, but naltrexone-induced changes in pain and pleasantness were mildly correlated. Moreover, naltrexone-induced changes in pain were related to depression scores, while naltrexone-induced changes in sweet pleasantness were related to anxiety scores, indicating that pain and pleasantness are related, but influenced by different processes.
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http://dx.doi.org/10.1007/s00213-016-4417-4 | DOI Listing |
Sci Rep
January 2025
Gynecology Department Institute Clinic of Gynecology, Obstetrics and Neonatology, Hospital Clinic, Faculty of Medicine, Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona, 08036, Barcelona, Spain.
Anhedonia, characterized by diminished motivation and pleasure sensitivity, is increasingly recognized as prevalent among patients with chronic pain. Deep Endometriosis (DE), the most severe endophenotype of the disease, is commonly presented with chronic pelvic pain. This cross-sectional study reports, for the first time, the prevalence of anhedonia in a sample comprised by 212 premenopausal women with suspected DE referred to a tertiary hospital.
View Article and Find Full Text PDFArch Sex Behav
December 2024
School of Psychology, University of Southampton, Southampton, UK.
Emotional labor, the act of suppressing or altering one's feelings to enhance another person's well-being, is predominantly performed by women, especially within intimate relationships. Despite its impact on well-being, research on its role in sexuality remains limited. We developed the Women's Sexual Emotional Labor Assessment (WOSELA), a 12-item scale based on themes identified by past qualitative studies.
View Article and Find Full Text PDFSelf-insertion of foreign bodies into the urethra is uncommon and is often associated with complex psychological or behavioral factors. Many cases of foreign bodies in the urethra have been reported worldwide with variable complaints of penile pain, penile itching, dysuria, hematuria, and complete obstruction of urine. These foreign objects are managed to remove according to their size, complexity of shape, and location in the urethra.
View Article and Find Full Text PDFDrug Alcohol Depend
January 2025
Center for Applied Psychology, Miguel Hernández University, Avenida Universidad, s/n, Elche 03202, Spain. Electronic address:
Cereb Cortex
January 2025
Department of Cognitive Sciences, University of California Irvine, Social & Behavioral Sciences Gateway Building, Irvine, CA 92697, United States.
Studying subjective experience is hard. We believe that pain is not identical to nociception, nor pleasure a computational reward signal, nor fear the activation of "threat circuitry". Unfortunately, introspective self-reports offer our best bet for accessing subjective experience, but many still believe that introspection is "unreliable" and "unverifiable".
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