|dc.description.abstract||"Rumination" and "Silencing the Self (1)" have both been theorised to explain women's greater vulnerability to depression. Rumination (Nolen-Hoeksema, e.g., 1987, 1991) refers to a passive focus on mood and symptoms, while Silencing the Self (Jack, 1991) refers to the socially-based belief that, broadly speaking, one should actively suppress one's negative emotions and thoughts within romantic relationships. This thesis proposes that frequent suppression of negative emotional material within romantic relationships (self-silencing) makes that material more likely to be a target for rumination, resulting in greater depressed mood and depressive symptoms.
It seems paradoxical that the more one tries to suppress one's thoughts, the more one thinks about them. Wenzlaff and Luxton (2003) have demonstrated that frequent suppression may make material more accessible and a more likely target of rumination. Study 1 was a pilot investigation. It was found that self-silencing (the broad construct) and thought suppression (a narrower construct) were related, and that both were positively correlated with rumination. Furthermore, thought suppression contributed to the relationship between self-silencing and rumination for women.
It was hypothesised that the more women suppress their negative feelings in romantic relationships (what Jack, 1991, describes as "Silencing the Self"), the more they will ruminate about these feelings and experience symptoms of depression. In Studies 2 and 3, the correlations among rumination, self-silencing and depression in adults and high school students were investigated. There were positive correlations among all the measured variables for adults and teenage girls, supporting the hypotheses. Regression analyses showed that for female adults and teenagers, rumination and self-silencing made unique, additive contributions to the prediction of depressive symptoms.
In Studies 4 and 5, the causal relationship among self-silencing, rumination and depressed mood was investigated. Participants were asked either to write about a sad event that had happened in their relationships, or a typical (neutral) event. In Study 4, participants were also instructed to write either factually about these events, or to write in a ruminative way about them. Participants' chronic tendencies to self-silence were measured and they were classed as "high" or "low" self-silencers based on a median split. Female participants who chronically self-silenced more frequently and who ruminated experienced the most dramatic decrease in mood. In Study 5 participants wrote factually or suppressed their feelings about sad or neutral events and their tendency to ruminate was measured. Participants were divided into "high" and "low" ruminators based on a median split of their rumination scores. There was no support for the alternative hypothesis that chronic ruminators who suppressed would report depressed mood.
Study 6 confirmed that in women, the combination of both chronic self-silencing in romantic relationships and acute rumination resulted in more severe symptoms of depression. Participants were e-mailed daily for one month about their self-silencing, rumination and negative mood. Chronic self-silencing, rumination and depressive symptoms were measured at the start and end of the month. Again, the combination of chronic self-silencing and acute rumination emerged as a better predictor of depressive symptoms than either variable alone.
The six studies reported in this thesis support the hypothesis that self-silencing and rumination together explain short term negative mood as well as depressive symptoms even after one month. These studies explain why certain women are more likely to experience depressed mood in the context of romantic relationships. In particular, the combination of being a high self-silencer and ruminating makes one especially vulnerable to depressed mood and depressive symptoms.
Clinically, there are already interventions targeted at rumination that are effective in reducing distress. However, the current research demonstrates that self-silencing may also be a promising target for intervention. Self-silencing is based on a wider understanding of the social context of depression. By targeting self-silencing, as well as rumination, depression may be more effectively treated.
(1) Throughout much of this thesis, the term "self-silencing" will be used to describe the active nature of this construct, and is consistent with the use of this term by other authors.||en_NZ