Dro deakin Research Online, Deakin University’s Research Repository
Yüklə 409,53 Kb. Pdf görüntüsü
|
- Bu səhifədəki naviqasiya:
- Investigating direct links between depression, emotional control, and physical punishment with adolescent drive for thinness and bulimic behaviours, including
| DRO
Deakin Research Online, Deakin University’s Research Repository Deakin University CRICOS Provider Code: 00113B Investigating direct links between depression, emotional control, and physical punishment with adolescent drive for thinness and bulimic behaviours, including possible moderation by the serotonin transporter 5-HTTLPR polymorphism Citation: Rozenblat, Vanja, Ryan, Joanne, Wertheim, Eleanor H, King, Ross, Olsson, Craig A and Krug, Isabel 2017, Investigating direct links between depression, emotional control, and physical punishment with adolescent drive for thinness and bulimic behaviours, including possible moderation by the serotonin transporter 5-HTTLPR polymorphism, Frontiers in psychology, vol. 8, Article number: 1361, pp. 1-9. DOI: 10.3389/fpsyg.2017.01361 © 2017, The Authors
Reproduced by Deakin University under the terms of the Creative Commons Attribution Licence
Downloaded from DRO: http://hdl.handle.net/10536/DRO/DU:30102209
fpsyg-08-01361 August 7, 2017 Time: 15:7 # 1
ORIGINAL RESEARCH published: 09 August 2017 doi: 10.3389/fpsyg.2017.01361 Edited by: Leigh Gibson, University of Roehampton, United Kingdom Reviewed by: Simone Munsch, University of Fribourg, Switzerland Ulrich Schweiger, Lübeck University Medical School, Germany *Correspondence: Vanja Rozenblat vanja@rozenblat.net Specialty section: This article was submitted to Eating Behavior, a section of the journal Frontiers in Psychology Received: 28 March 2017 Accepted: 26 July 2017 Published: 09 August 2017 Citation: Rozenblat V, Ryan J, Wertheim EH, King R, Olsson CA and Krug I (2017) Investigating Direct Links between Depression, Emotional Control, and Physical Punishment with Adolescent Drive for Thinness and Bulimic Behaviors, Including Possible Moderation by the Serotonin Transporter 5-HTTLPR Polymorphism. Front. Psychol. 8:1361. doi: 10.3389/fpsyg.2017.01361 Investigating Direct Links between Depression, Emotional Control, and Physical Punishment with Adolescent Drive for Thinness and Bulimic Behaviors, Including Possible Moderation by the Serotonin Transporter 5-HTTLPR Polymorphism Vanja Rozenblat 1 *, Joanne Ryan 2 , Eleanor H. Wertheim 3 , Ross King 4 , Craig A. Olsson 2,4,5 and Isabel Krug 1 1 School of Psychological Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia, 2 Murdoch Childrens Research Institute, Royal Children’s Hospital Melbourne, Parkville, VIC, Australia, 3 School of Psychology and Public Health, Faculty of Health, La Trobe University, Melbourne, VIC, Australia, 4 School of Psychology, Faculty of Health, Centre for Social and Early Emotional Development, Deakin University, Geelong, VIC, Australia, 5 Department of Paediatrics, The Royal Children’s Hospital Melbourne, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia Objectives: To examine the relationship between psychological and social factors (depression, emotional control, sexual abuse, and parental physical punishment) and adolescent drive for Thinness and Bulimic behaviors in a large community sample, and to investigate possible genetic moderation. Method: Data were drawn from the Australian Temperament Project (ATP), a population-based cohort study that has followed a representative sample of 2443 participants from infancy to adulthood across 16 waves since 1983. A subsample of 650 participants (50.2% female) of Caucasian descent who provided DNA were genotyped for a serotonin transporter promoter polymorphism (5-HTTLPR). Adolescent disordered eating attitudes and behaviors were assessed using the Bulimia and Drive for Thinness scales of the Eating Disorder Inventory-2 (15–16 years). Depression and emotional control were examined at the same age using the Short Mood and Feelings Questionnaire, and an ATP-devised measure of emotional control. History of sexual abuse and physical punishment were assessed retrospectively (23–24 years) in a subsample of 467 of those providing DNA. Results: EDI-2 scores were associated with depression, emotional control, and retrospectively reported parental physical punishment. Although there was statistically significant moderation of the relationship between parental physical punishment and bulimic behaviors by 5-HTTLPR (p = 0.0048), genotypes in this subsample were not in Hardy–Weinberg Equilibrium. No other G×E interactions were significant. Frontiers in Psychology | www.frontiersin.org 1 August 2017 | Volume 8 | Article 1361 fpsyg-08-01361 August 7, 2017 Time: 15:7 # 2
Rozenblat et al. 5-HTTLPR and Disordered Eating Conclusion: Findings from this study affirm the central importance of psychosocial processes in disordered eating patterns in adolescence. Evidence of moderation by 5- HTTLPR was not conclusive; however, genetic moderation observed in a subsample not in Hardy–Weinberg Equilibrium warrants further investigation. Keywords: 5-HTTLPR, gene–environment interactions, disordered eating, parental physical punishment, depression, emotional control INTRODUCTION Eating disorders (EDs) are believed to have a substantial heritable component ( Bulik et al., 2016 ), with estimates from twin studies ranging from 40 to 60% ( Yilmaz et al., 2015 ). Thus
far, research examining molecular genetic mechanisms that may increase risk for eating pathology has largely investigated whether certain genetic polymorphisms (e.g., serotonin transporter linked polymorphism, 5-HTTLPR) are found in different frequency in those with a clinical ED compared to controls. These studies have largely produced inconsistent findings ( Calati et al., 2011 ; Solmi
et al., 2016 ), supporting the notion that genetic risk operates in a manner more complex than simple association. One line of research receiving increasing attention is the possibility that certain polymorphisms may induce differential risk, depending upon exposure to certain environmental factors, via gene by environment (G×E) interaction. Studies examining whether G×E interactions play a role in ED etiology have largely focussed on 5-HTTLPR, with the short (s) allele associated with lower serotonin transcription activity compared to the long (l) allele ( Heils et al., 1996 ). Serotonin plays a role in mood regulation, appetite, and weight ( Blundell, 1984 ; Leibowitz and Alexander, 1998 ; Kalra et al., 1999 ;
), all known to be involved in eating pathology. Serotonin is also involved in the stress-response system ( Gotlib et al., 2008 ; van Eekelen et al., 2012 ), and as 5-HTTLPR is a functional polymorphism it may conceivably play a role in EDs, directly or indirectly through interaction with other environmental stressors. However, in other fields of psychiatry, the role of 5-HTTLPR in moderating the effects of environmental stressors remains controversial; for example, in depression, where independently conducted meta-analysis continue to contradict one another (cf. Munafò et al., 2009 ; Risch
et al., 2009 ; Karg et al., 2011 ). Lack of consensus stems from a range of methodological limitations, such as insufficient sample size, inappropriate statistical techniques and multiple testing, as well as substantial publication bias favoring significant G×E findings ( Duncan and Keller, 2011 ; Duncan et al., 2014 ; Dick
et al., 2015 ; de Vries et al., 2016 ). To date, seven publications have investigated the role of G×E interactions in the ED field involving 5-HTTLPR ( Rozenblat et al., 2017 ). Systematic review and meta-analysis of these studies suggested that 5-HTTLPR may moderate the risk relationship between experiencing both sexual and physical abuse and bulimic symptomatology (combined N = 1,096), and traumatic life events and ED symptomatology ( N = 909). This was not the case, however, for risk relationships between depressive and bulimic symptomatology ( N = 1254) or impulsivity and disordered eating (
N = 1122). Findings from this review suggest that risk associated with 5-HTTLPR may be intensified under increasingly severe social stress, but not psychological distress. However, findings from this work were based on a combined sample that was derived by summing across small highly heterogeneous samples [e.g., two community samples, N = 369,
Akkermann et al., 2012 ; N = 623, van Strien et al., 2010 ; a
clinical sample, N = 89,
Richardson et al., 2008 ; and a discordant sister-pair sample, N = 168 from European cross-institutional data set used in Karwautz et al. (2011) ]. Testing interactions in one large, homogenous sample would be preferable ( Cochran, 1954
). This, for example, may explain why 5-HTTLPR was found to moderate the effects of depression on eating outcomes in two of the original studies ( van Strien et al., 2010 ; Mata and Gotlib, 2011 ) but not in the combined data analysis ( Rozenblat et al., 2017 ). Furthermore, the lack of significant interaction between impulsivity and 5-HTTLPR in the combined-sample may be partly due to the analysis of impulsivity as an overall construct, rather than separately testing the particular facets of impulsivity that have previously been associated with EDs, such as negative urgency ( Racine et al., 2009, 2013 ). Negative urgency refers to the tendency to act rashly or feel strong impulses when experiencing negative affect ( Whiteside and Lynam, 2001 ), and, along with the broader ability to regulate one’s emotions, has wide empirical support for a role in EDs, particularly bulimia nervosa symptomatology ( Fischer et al., 2003 ; Claes et al., 2005 ), with some evidence linking emotional regulation and 5-HTTLPR function ( Hariri and Holmes, 2006 ). From a theoretical perspective, lowered emotional control may lead to greater eating pathology, as individuals may attempt to control their emotional states via altered food intake (e.g., binge eating or restricted intake; Haynos and Fruzzetti, 2011 ; Pearson et al., 2015 ). Meanwhile, the other psychological factor that has been analyzed in a G×E framework, depressed mood, is believed to precipitate bulimic behaviors under a number of key ED models (e.g., Dual Pathway Model; Stice, 2001 ) with support from longitudinal investigations of high-risk samples ( Stice et al., 2017 ), although there is evidence suggesting depressed mood may also arise as a consequence of eating pathology ( Puccio et al., 2016 ). While many prior studies investigating G×E interactions have focussed on patients with clinical EDs ( Rozenblat et al., 2017 ), analysis of disordered eating in community samples is of equal, if not greater importance. Developing a better understanding of the correlates and risk factors for pre-clinical eating pathology, which may later develop into a ‘full blown’ ED ( Herpertz-Dahlmann et al., 2013 ), can help promote prevention at the earliest possible opportunity to reduce ED incidence ( Stice et al., 2007 ). From Frontiers in Psychology | www.frontiersin.org 2 August 2017 | Volume 8 | Article 1361 Yüklə 409,53 Kb. Dostları ilə paylaş:
|