The role of peer rejection in adolescent depression: genetic, neural and cognitive correlates

Thesis

Adolescent depression is a major public health problem, which is associated with educational problems, long-term psychiatric illness and suicide. One major source of stress during adolescence is peer rejection. In this thesis, I investigate the nature of the relationship between peer rejection and adolescent depression. In a review of longitudinal and experimental studies, I describe a bi-directional relationship between peer rejection and depressive symptoms. I then outline how genetic, cognitive and neural vulnerability may modify the effects of peer rejection on adolescent depression. Finally, I introduce five empirical chapters which test these hypotheses using different methodological approaches. The first study is a molecular genetic analysis of a sample of adolescents with and without a diagnosis of mood disorder. I report an interaction between diagnostic group, environmental stress (though not peer rejection specifically) and 5HTTLPR genotype on symptoms of anxiety, which supports the role of genetic factors in modifying the relationship between environmental stress and adolescent mood disorder. The second study is a behavioural study of negative attention biases in a typically developing sample of adolescents. I report a negative attention bias in adolescents with low (versus high) self-esteem. Although the data do not support a causal role for attention biases in adolescent depression, such biased cognitions could also moderate responses to peer rejection, maintaining affective symptoms. A final set of three fMRI datasets investigates how neural circuitry may influence depressed adolescents’ responses to peer rejection at three distinct stages: i) expectation of peer feedback, ii) the receipt of peer rejection, iii) emotion regulation of peer rejection. Data show distinct behavioural and neural differences between depressed patients and healthy controls during expectation and reappraisal of peer rejection, although heightened emotional reactivity immediately following the receipt of peer rejection did not differentiate behavioural or neural responses in adolescents with and without depression.

Authors: Platt, B; Belinda Platt

• Publication date: 2013
• DOI: 10.5287/ora-4jgp2ev5m
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: Oxford University, UK
• Language: English
• Keywords: functional magnetic resonance imaging; peer rejection; molecular genetics; depression; adolescence; ostracism; cognitive bias modification
• Subjects: Developmental psychology; Child and adolescent psychiatry; Experimental psychopathology; Cognitive Neuroscience