MAJOR UNIPOLAR DEPRESSION--论文代写范文精选

有充分的证据表明,缺乏社会支持和关爱是产后抑郁症的原因,缺乏资源,关注照顾孩子的能力也与产后抑郁症密切相关(哈根1999)。抚养孩子的成本,其他人可以减轻似乎导致产后抑郁症。下面的essay代写范文进行详述。

Abstract
Numerous studies have shown that circumstances in which individuals may need to compel social assistance — adverse life events — are a potent cause of depression (Kendler et al. 1995; Mazure et al. 2000). Kendler et al.’s (1993) etiologic model of depression among female twins captures the essentials as well as any. In a longitudinal study of 680 female-female twin pairs, Kendler et al. found that the strongest predictors of a major depressive episode were, in descending order, (a) recent stressful life events, (b) genetic factors, (c) previous history of major depressive disorder, and (d) neuroticism. Their full, nine-variable model explained 50.1% of the variance in liability to depression (see also Kendler et al. 2002). 

For illustration, the four adverse life events which predicted onset of major depression in women with an odds ratio of 10 in a study by Kendler et al. (1995) were death of a close relative, assault, serious marital problems, and divorce/breakup. Cross-culturally, depression case rates strongly covary with rates of adverse life events (Brown 1998). Decades of research have shown that postpartum depression (PPD) is similar, if not identical, to depression in general (e.g., Whiffen and Gotlib 1993), and is therefore a good model for depression.4 Human mothers should not automatically invest in offspring, but rather should weigh the decision carefully based on infant viability, levels of social support, access to resources, negative consequences for their other children, etc. (Trivers 1972; Clutton-Brock 1991). There is excellent evidence that lack of social support is a cause of PPD and substantial evidence that problems with the pregnancy, delivery, or infant, lack of resources, and concern about their ability to care for their other children are also closely associated with PPD (Hagen 1999). Childrearing costs that others could mitigate appear to cause PPD.

Social Constraints: Viscous Social Markets and Monopoly Power 
Akey prediction of the bargaining model is that depression should be caused not simply by loss, failure, and other social costs, but also by circumstances where individuals cannot unilaterally alleviate these costs. There is considerable evidence that this is the case. A perceived inability to control events — variously termed external locus-of-control (e.g., Rotter 1966), helplessness or hopelessness (Abramson et al. 1989), or entrapment (Brown 1998) — is clearly implicated in depression. Meta-analyses of nearly 100 studies (Benassi et al. 1988; Presson and Benassi 1996) found that external locus-of-control and depression were significantly related, that the relation was moderately strong, and that it was consistent across studies; in addition, a belief that events were controlled by powerful others and chance was associated with higher levels of depression. 

Under the bargaining model, depression is a strategy to redress the causes of helplessness/ hopelessness/lack-of-control/entrapment and that is why depression is expected to be associated with them. In the EEA, even seemingly irredeemable losses, such as the abandonment by or death of a spouse, could often have been readily addressed by powerful individuals in one’s social group. Studies of PPD also support the contention that constraints on unilateral action are associated with depression. Hagen (2002) found that for mothers in general, there was no correlation between social constraints on abortion and their PPD levels, nor should there have been. Asocial constraint on abortion is inconsequential for mothers who want the new child. The depression scores of mothers with unwanted or unplanned pregnancies, however, significantly positively correlated with their perception that having an abortion would damage their relationship with their spouse (there was, however, an interesting nonlinearity). 

Because mothers’ perceptions could have been biased by their depression levels, fathers were also asked to report how much damage a wife’s abortion would have caused their relationship. Fathers’ perceptions of damage also correlated with mothers’ depression levels, suggesting that actual, and not merely perceived, social constraints on reproductive decision making are associated with PPD. Men’s reproductive decisions are also constrained. Men, but not women, can substantially increase their reproductive success by mating with multiple partners. Hence, the opportunity cost of socially imposed monogamy is predicted to be much higher for men, especially during the postpartum period when their nursing wives are infertile, encumbered with a new infant, and therefore significantly hindered from finding other mates. This cost, however, will only be borne by men who have additional mating opportunities. Hagen (2002) found exactly this. Men with more sexual opportunities were more depressed postpartum, whereas women with more sexual opportunities were not. About one half the effect for men was found to be due to relationship problems, whereas the other half was due simply to sexual opportunities.

Conflicts of Interest and Private Information in the EEA 
In the bargaining model, a need to influence others plus the inability to act unilaterally are necessary, but not sufficient, to cause major depression. There must also be a conflict of interest between group members and the individual, a conflict that can arise, in part, from private information (if there were no conflict, group members would simply provide the needed benefits). Note that this conflict need not be overt nor even consciously recognized by those involved. Although the evidence presented above certainly suggests a conflict with others, there is also considerable direct evidence that social conflict is involved. 

In a meta-analysis of 48 studies, Finch et al. (1999) found that social negativity had a significant correlation with depression in the expected direction, and results of longitudinal studies suggest a causal influence of negative social interactions on subsequent depression (e.g., Vinokur and van Ryn 1993); depression may, in turn, exacerbate social negativity (e.g., Coyne 1976). A follow-up study by Finch et al. (1999) suggests that interference/hindrance, anger, and insensitivity are the three aspects of social negativity that are most salient as predictors of depression. Each seems relevant to the bargaining model. 

Conclusion
Because changing social relations within a group can be a difficult and costly affair, most group members will resist such a change without clear evidence that it is necessary (Watson and Andrews 2002); otherwise group members could easily be exploited by deceptive individuals. If the individual has information that she is suffering a cost, but the other group members do not, the individual must credibly communicate this private information to others. Because this is a 106 E.H. Hagen novel aspect of the bargaining model, there is no evidence (yet) that private information is associated with depression. It is very likely, however, that individuals often had private information about their costs and benefits in important cooperative ventures. Childrearing provides a nice example. The mother, having carried the child for nine months, may have considerable information about its health that is unavailable to either the father or other family members, or she may have information about her own health that necessitates changing her levels of investment.

51Due网站原创范文除特殊说明外一切图文著作权归51Due所有；未经51Due官方授权谢绝任何用途转载或刊发于媒体。如发生侵犯著作权现象，51Due保留一切法律追诉权。
更多essay代写范文欢迎访问我们主页 www.51due.com 当然有essay代写需求可以和我们24小时在线客服 QQ:800020041 联系交流。-X