Dispositional optimism is a potentially modifiable factor and has been associated with multiple physical health outcomes, but its relationship with depression, especially later in life, remains unclear. In the Nurses´ Health Study (n = 33,483), we examined associations between dispositional optimism and depression risk in women aged 57–85 (mean = 69.9, SD = 6.8), with 4,051 cases of incident depression and 10 years of follow-up (2004–2014). We defined depression as either having a physician/clinician-diagnosed depression, or regularly using antidepressants, or the presence of severe depressive symptoms using validated self-reported scales. Age- and multivariable-adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs) across optimism quartiles and for a 1-standard deviation (SD) increment of the optimism score. In sensitivity analyses we explored more restrictive definitions of depression, potential mediators, and moderators. In multivariable-adjusted models, women with greater optimism (top vs. bottom quartile) had a 27% (95%CI = 19–34%) lower risk of depression. Every 1-SD increase in the optimism score was associated with a 15% (95%CI = 12–18%) lower depression risk. When applying a more restrictive definition for clinical depression, the association was considerably attenuated (every 1-SD increase in the optimism score was associated with a 6% (95%CI = 2–10%-) lower depression risk. Stratified analyses by baseline depressive symptoms, age, race, and birth region revealed comparable estimates, while mediators (emotional support, social network size, healthy lifestyle), when combined, explained approximately 10% of the optimism-depression association. As social and behavioral factors only explained a small proportion of the association, future research should investigate other potential pathways, such as coping strategies, that may relate optimism to depression risk.

性格乐观是一个潜在的可改变因素，并与多种身体健康结果相关，但其与抑郁症的关系，尤其是晚年的抑郁症，仍不清楚。在护士健康研究（n = 33,483）中，我们检查了 57-85 岁女性的性格乐观与抑郁风险之间的关联（平均值 = 69.9，SD = 6.8），有 4,051 例抑郁症事件和 10 年的随访（2004-2014）。我们将抑郁症定义为医生/临床医生诊断为抑郁症，或定期使用抗抑郁药，或使用经过验证的自我报告量表存在严重抑郁症状。年龄和多变量调整 Cox 比例风险模型用于估计风险比 (HR)，乐观四分位数为 95% 置信区间 (95% CI) 和 1 个标准差 ( SD) 乐观分数的增量。在敏感性分析中，我们探索了对抑郁症、潜在中介和调节者的更严格定义。在多变量调整模型中，更乐观的女性（最高与最低四分位数）患抑郁症的风险降低了 27%（95%CI = 19-34%）。乐观评分每增加 1-SD 与抑郁风险降低 15% (95%CI = 12–18%) 相关。当对临床抑郁症应用更严格的定义时，这种关联显着减弱（乐观评分每增加 1-SD 与抑郁症风险降低 6% (95%CI = 2–10%-) 相关。按基线进行分层分析抑郁症状、年龄、种族和出生地区显示出可比较的估计值，而中介因素（情感支持、社交网络规模、健康生活方式）结合起来，解释了大约 10% 的乐观-抑郁关联。由于社会和行为因素只解释了一小部分关联，未来的研究应该调查其他可能的途径，例如应对策略，这些途径可能将乐观情绪与抑郁症风险联系起来。