Cultural influences on positive affect and reward processing in depressed youth

Thesis (Ph.D.)--University of Washington, 2016-07

Adolescent onset of depression is a public health concern because it is common and has been linked with subsequent episodes of depression, substance abuse, impaired social and academic functioning, and suicidal tendencies (Emslie et al, 2008; Kovacs, 1996; Kovacs et al.,1984; Weissman et al., 1999). Diminished positive affect and disrupted reward function, seen as the neural characteristic of positive affect, are implicated in early episodes of depression and also predict recurrent episodes of depression (Forbes, 2011; Joiner, Lewinsohn, & Seeley, 2002; Nandrino et al., 2004). Thus, studying positive affect and reward during the developmental period of adolescence may help us better understand the emergence of depression. An increasing number of studies acknowledge the importance of examining the role of culture in the expression of depression. However, few studies have looked specifically at culture and reward dysfunction, and even fewer have looked at these constructs during a developmental period when depression is emerging. The expression of positive affect is shown to be shaped by cultural norms, with Asian Americans in general reporting less intense positive emotions than European Americans due to the cultural emphasis to control and moderate emotion (Eid & Diener, 2001; Russell & Yik, 1996). In order to better understand the emergence of depression within this population, it may be useful to assess positive affect with measures that are less influenced by subjective experience. Prior research suggests that while culture may alter the subjective experience of emotion, there may be less contribution of culture with regards to physiological response (Levenson, 1999). Disrupted reward anticipation has been examined using electroencephalographic (EEG) measurements and several studies have found abnormal reward circuitry when comparing depressed to nondepressed samples (Davidson, 1998; Debener et al., 2000; Foti et al., 2011). The overarching goal of this study is to explore how culture affects the expression of positive affect and reward among depressed Asian American and European American adolescents using multiple methods of data collection. The following hypotheses were examined: (1) whether race/ethnicity affects the relation between self-reported positive affect and depressive symptoms; (2) whether neural reactivity, measured using ERP P3 amplitude, towards both monetary and social reward predicts depressive symptoms and if this association is affected by race/ethnicity; and (3) if acculturation moderates the expression of positive affect and reward for Asian American adolescents. Data was gathered in two phases in order to evaluate study hypotheses. In Phase One, 825 participants ages 18-19 were asked to fill out self-report measures online that assess for depression, positive affect, and acculturation. In Phase Two, 68 females were selected from Phase One based on race/ethnicity. Asian American participants were matched with European American counterparts based on depression severity on the PHQ-9 depression measure (Spitzer, Kroenke, & Williams, 1999). During the Phase Two lab visit, ERP data were collected during a cued go/no-go task. Participants also completed a structured depression interview on the YA-DISC-IV (Shaffer, 2000). Results suggest the negative association between positive affect and depression was significantly stronger for European American participants compared to Asian Americans. In addition, a trend towards significance was found with European American participants exhibiting increased P3 reactivity towards smiling European American faces as level of depression increased. Results from the proposed study can be used to guide the development of culturally sensitive ways to detect, prevent, and intervene with depression in Asian American youth.