title: Adult attachment style is associated with cerebral μ-opioid receptor availability in humans.
abstract: Human attachment behavior mediates establishment and maintenance of social relationships. Adult attachment characteristically varies on anxiety and avoidance dimensions, reflecting the tendencies to worry about the partner breaking the social bond (anxiety) and feeling uncomfortable about depending on others (avoidance). In primates and other mammals, the endogenous μ-opioid system is linked to long-term social bonding, but evidence of its role in human adult attachment remains more limited. We used in vivo positron emission tomography to reveal how variability in μ-opioid receptor (MOR) availability is associated with adult attachment in humans. We scanned 49 healthy subjects using a MOR-specific ligand [(11) C]carfentanil and measured their attachment avoidance and anxiety with the Experiences in Close Relationships-Revised scale. The avoidance dimension of attachment correlated negatively with MOR availability in the thalamus and anterior cingulate cortex, as well as the frontal cortex, amygdala, and insula. No associations were observed between MOR availability and the anxiety dimension of attachment. Our results suggest that the endogenous opioid system may underlie interindividual differences in avoidant attachment style in human adults, and that differences in MOR availability are associated with the individuals' social relationships and psychosocial well-being.
authors.affiliation: Turku PET Centre, University of Turku, Turku, 20520, Finland.|Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, 00076, AALTO, Espoo, Finland.|Department of Psychology, University of Turku, 20014, Turku, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Nummenmaa
authors.affiliation: Turku PET Centre, University of Turku, Turku, 20520, Finland.
authors.forename: Sandra
authors.initials: S
authors.lastname: Manninen
authors.affiliation: Turku PET Centre, University of Turku, Turku, 20520, Finland.|Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, 00076, AALTO, Espoo, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Tuominen
authors.affiliation: Turku PET Centre, University of Turku, Turku, 20520, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Hirvonen
authors.affiliation: Turku PET Centre, University of Turku, Turku, 20520, Finland.
authors.forename: Kari K
authors.initials: KK
authors.lastname: Kalliokoski
authors.affiliation: Turku PET Centre, University of Turku, Turku, 20520, Finland.|Department of Endocrinology, Turku University Hospital, 20521, Turku, Finland.
authors.forename: Pirjo
authors.initials: P
authors.lastname: Nuutila
authors.affiliation: Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, 00076, AALTO, Espoo, Finland.
authors.forename: Iiro P
authors.initials: IP
authors.lastname: Jääskeläinen
authors.affiliation: Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, 00076, AALTO, Espoo, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Hari
authors.affiliation: Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, 00076, AALTO, Espoo, Finland.|Department of Experimental Psychology, University of Oxford, Oxford, Ox1 3UD, UK.
authors.forename: Robin I M
authors.initials: RI
authors.lastname: Dunbar
authors.affiliation: Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, 00076, AALTO, Espoo, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Sams
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001931:Brain Mapping; D002250:Carbon Radioisotopes; D005260:Female; D005283:Fentanyl / Q000031:analogs & derivatives; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D009769:Object Attachment; D049268:Positron-Emission Tomography; D011581:Psychological Tests; D019275:Radiopharmaceuticals; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; C485764:OPRM1 protein, human; D019275:Radiopharmaceuticals; D017450:Receptors, Opioid, mu; C017114:carfentanil; D005283:Fentanyl
keywords: attachment; emotion; neurotransmitters; opioids; positron emission tomography; social interaction