ATTACHMENT PROCESSES AND GENE-ENVIRONMENT INTERACTIONS: Testing Two Initial Hypotheses Regarding the Relationship between Attachment, and Methylation of the Glucocorticoid Receptor Gene (NR3C1) and the Serotonin Transporter Gene (SLC6A4)
By
Karen Jones-Mason
Doctor of Philosophy in Social Welfare
University of California, Berkeley
Professor Jill Duerr Berrick, Ph.D., Co-Chair
Professor Steve Hamilton, Ph.D., M.D., Co-Chair
This study seeks to determine whether methylation levels of a polymorphism in the serotonin gene-linked promoter region (5-HTTLPR) associated with the serotonin transporter gene (SCL6A4), and of the Glucocorticoid Receptor gene (NR3C1) (GR), determined from peripheral blood samples, differ among 93 participants, approximately 18-25 years of age, according to attachment "state of mind" and socio-economic status (SES). Attachment state of mind is determined by two measures: the Adult Attachment Interview (AAI) and a new measure called the Adult Attachment Projective (AAP). The extent of convergent agreement between the AAP and the AAI is reported. SES was determined by the Hollingshead Scale of SES (HSES) and the Family Affluence Scale (FAS), and the correlation between the HSES and the FAS is reported. Participants were also administered the MacArthur Measure of Subjective Social Status (MSSS) and the MacArthur Measure of Subjective SES (MSES) to determine if subjective measures of SES and social status differ based on attachment classification. It is hoped that determining whether the relationship between attachment state of mind and SES impacts genetic expression will help researchers understand the biological mechanisms underlying the dynamic between early life experience and development, and inform future treatment for those who develop pathology as a result of adverse life experiences. Findings: No convergence was detected between the AAI and the AAP; a significant correlation was found between the HSES and the FAS; the higher the participants objective and subjective perception of SES, the higher the MSSS score; in the lower HSES category, a trend toward higher MSSS scores among secure vs. insecure participants was detected; and ss genotype was associated with unresolved attachment classification (determined by AAI) when participants were divided into the U vs. non-U classifications, and into the ss vs. sl/ll genotypes only in participants self-identified as Hispanic. Using principal component analysis (PC), marginally significant differences in methylation levels were detected among all participants according to HSES among unresolved participants. Using PC analysis, lower HSES unresolved participants among the Asian-American and Hispanic participants had significantly higher levels of methylation than upper SES unresolved participants. Although more research with a larger sample size is necessary, results suggest that methylation levels may be set or moderated by attachment classification and SES.