Reward Processing and High-Risk Behaviour in Adolescents with a History of Childhood Abuse
Thesis or dissertation
University of Exeter
Embargo until 14th March 2018 as document is being prepared for publication.
Reason for embargo
Thesis will be prepared for publication.
Systematic Literature Review: Abstract Objective: Childhood abuse (CA) is commonly associated with increased frequency of high-risk behaviours (HRB) in adolescence. Similarly, research has highlighted links between CA and blunted responses to reward. To date, little attention has been devoted to examine if altered reward processes may also be linked to increased engagement in HRB. To explore this hypothesis, this systematic review collated research that investigated the relationship among CA, reward processes and HRB. Specifically, the review addressed the question: Are HRB associated with altered reward processes in children and adults with a history of CA? Method: Behavioural and neurobiological studies on CA, reward processing and HRB in children and adults were selected from multidisciplinary and subject-specific databases published prior to the 1st of March 2016. The systematic literature search yielded 271 records with 198 non-duplicated results. Screening of 14 full-text publications led to five eligible studies synthesized in this review. Results: Results confirmed impaired reward learning and increased HRB in those with a history of CA. Associations of blunted anticipatory or consummatory reward processing and HRB in individuals with CA remained inconclusive. Conclusions: Reward learning appears to be associated with CA. Further research is required to explore the relationship between reward processes and HRB. Understanding CA from a neurodevelopment perspective is a critical step to developing effective intervention strategies to reduce HRB. Empirical Paper: Abstract Objective: Following childhood abuse (CA), adolescence often sees the onset of depression and high-risk behaviour (HRB). Despite the prevalence, little is known about underlying neurobiological factors linking CA and HRB. To address this gap, I examined if anticipatory and consummatory reward processing in adolescents with CA predict frequency of HRB, irrespective of depressive symptoms. Methods: Thirty-seven adolescents (M=17.08 years; SD = 1.86) participated in the study: 13 females with CA and current major depressive disorder (MDD), eight females with MDD and no CA, and 16 individuals with no CA and no MDD for comparison (control group). Adolescents completed the Card-Guessing paradigm to assess reward processing, while undergoing a magnetic resonance imaging scan. Neural region-of-interest responses in the striatum and pallidum were assessed during anticipatory and consummatory reward phases. Hierarchical regression models investigated if neural responses to reward were altered based on exposure to CA and if altered neural responses predicted higher use of HRB. Results: Data showed that (1) depressed adolescents engaged more frequently in HRB irrespective of history of CA, (2) anticipatory and consummatory reward processes were not altered based on a history of CA, and (3) blunted activation in right pallidum in anticipation of rewards predicted HRB irrespective of depressive symptoms. Conclusion: Although the current study did not confirm changes in reward processing following CA, blunted reward ‘wanting’ was linked to more frequent HRB. Findings are relevant to theories highlighting the critical role of the pallidum in perceiving cues as rewarding and in initiating goal-directed actions to obtain rewards.
Young Investigator Award from the Brain and Behaviour Research Foundation (NARSAD)
Funding for this study was provided by a Young Investigator Award from the Brain and Behaviour Research Foundation (NARSAD – Grant Number: 18774) awarded to Pia Pechtel. Pia Pechtel reports no biomedical financial interests or potential conflicts of interest.
Doctorate of Clinical Psychology