title: Blocking opioids attenuates physical warmth-induced feelings of social connection.
abstract: "Heartwarming" social experiences, when one feels interpersonally connected to others, have recently been linked with physical warmth. According to one theory (Panksepp, 1998), "social warmth" and physical warmth may be closely linked because both experiences are supported by similar neurobiological mechanisms; however, the neurochemical substrates underlying this overlap have not been explored. Here, an opioid antagonist, naltrexone, was administered in order to examine the role of opioids, previously shown to alter temperature and social bonding behavior, on perceived thermal intensity, general positive affect, and feelings of social connection from physical warmth. Thirty-one participants took both naltrexone and a placebo and completed a temperature manipulation task (held a warm pack, cold pack, and neutral object) while on each drug. Replicating previous research, holding a warm (vs. a cold or neutral) object increased feelings of social connection. Moreover, blocking opioids reduced this effect. Hence, naltrexone specifically reduced feelings of social connection to holding a warm (vs. neutral) object but not to holding a cold (vs. neutral) object. These results lend further support to the theory that social and physical warmth share neurobiological, opioid receptor dependent mechanisms.
authors.affiliation: Department of Psychology, University of California, Los Angeles.
authors.forename: Tristen K
authors.initials: TK
authors.lastname: Inagaki
authors.affiliation: Semel Institute for Neuroscience and Human Behavior, Cousins Center for Psychoneuroimmunology, University of California, Los Angeles.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Irwin
authors.affiliation: Department of Psychology, University of California, Los Angeles.
authors.forename: Naomi I
authors.initials: NI
authors.lastname: Eisenberger
mesh_terms: D000293:Adolescent; D000328:Adult; D001831:Body Temperature / Q000187:drug effects*; D004644:Emotions / Q000187:drug effects*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D009271:Naltrexone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009769:Object Attachment; D018847:Opioid Peptides / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011957:Receptors, Opioid / Q000378:metabolism*; D012919:Social Behavior; D055815:Young Adult
chemical_list: D009292:Narcotic Antagonists; D018847:Opioid Peptides; D011957:Receptors, Opioid; D009271:Naltrexone