This study examined the prospective course of posttraumatic stress disorder (PTSD) symptoms in a cohort of National Guard soldiers (N = 522) deployed to combat operations in Iraq. Participants were assessed 4 times: 1 month before deployment, 2–3 months after returning from deployment, 1 year later, and 2 years postdeployment. Growth mixture modeling revealed 3 distinct trajectories: low‐stable symptoms, resilient, 76.4%; new‐onset symptoms, 14.2%; and chronic distress, 9.4%. Relative to the resilient class, membership in both the new‐onset symptoms and chronic distress trajectory classes was predicted by negative emotionality/neuroticism, odds ratios (ORs) = 1.09, 95% CI [1.02, 1.17], and OR = 1.22, 95% CI [1.09,1.35], respectively; and combat exposure, OR = 1.07, 95% CI [1.02, 1.12], and OR = 1.12, 95% CI [1.02, 1.24], respectively. Membership in the new‐onset trajectory class was predicted by predeployment military preparedness, OR = 0.95, 95% CI [0.91, 0.98], perceived threat during deployment, OR = 1.07, 95% CI [1.03, 1.10], and stressful life events following deployment, OR = 1.44, 95% CI [1.05, 1.96]. Prior deployment to Iraq or Afghanistan, OR = 3.85, 95% CI [1.72, 8.69], predeployment depression, OR = 1.27, 95% CI [1.20, 1.36], and predeployment concerns about a deployment's impact on civilian/family life, OR = 1.09, 95% CI [1.02, 1.16], distinguished the chronic distress group relative to the resilient group. Identifying predeployment vulnerability and postdeployment contextual factors provides insight for future efforts to bolster resilience, prevent, and treat posttraumatic symptoms. Este estudio examinó el curso prospectivo de los síntomas del trastorno por estrés postraumático (TEPT) en una cohorte de Soldados de la Guardia Nacional (N = 522) desplegados para operaciones de combate en Iraq. Los participantes fueron evaluados cuatro veces: un mes antes del despliegue, 2 a 3 meses después del retorno tras el despliegue, 1 año y 2 años después del despliegue. El modelo de crecimiento de mezcla reveló tres trayectorias distintas: síntomas bajos y estables, resiliente, 76,4%; síntomas de inicio nuevo, 14,2%; y estrés crónico, 9,4%. Relativo a la clase resiliente, la pertenencia tanto a las clases de los síntomas de inicio nuevo, y la trayectorias de estrés crónico fue predicha por emocionalidad negativa/neuroticismo, razón de probabilidades (OR) = 1,09, 95% CI [1,02, 1,17] y OR = 1,22, 95% CI [1,09, 1,35], respectivamente; y exposición a combate OR = 1,07, 95% CI [1,02, 1,12] y OR = 1,12, 95% CI [1,02, 1,24], respectivamente. Pertenecer a la clase de trayectoria de inicio nuevo fue predicho por la preparación militar previa al despliegue, OR = 0,9, 95% CI [0,91, 0,98]; amenaza percibida durante el despliegue, OR = 1,44, 95% CI [1,03, 1,10; y eventos vitales estresantes tras el despliegue, OR = 1m44m 95% CI [1,05, 1,96]. Previo al despliegue a Iraq o Afganistán, OR = 3,85, 95% CI [1,72‐8,69]; depresión pre despliegue, OR = 1,27, 95% CI [1,20, 1,36]), y preocupaciones pre despliegue sobre el impacto del despliegue sobre la vida civil o familiar, OR = 1,09, 95% CI [1,02, 1,16], distinguiendo el grupo de estrés crónico con el grupo resiliente. Identificar la vulnerabilidad pre despliegue y factores contextuales post despliegue provee entendimiento sobre futuros esfuerzos para reforzar la resiliencia, prevenir, y tratar los síntomas postraumáticos. Traditional Chinese 標題: 出征伊拉克的美國國民警衛隊的恢復力與創傷後壓力症狀:針對潛在組別軌跡及其預測變量的前瞻性研究 撮要: 本研究透過出征伊拉克戰鬥的美國國民警衛隊樣本(N = 522), 檢視創傷後壓力症(PTSD)症狀的前瞻性發展。樣本接受了4次評估:於服役前1個月、完成服役歸來2至3個月後、1年後和2年後。增長混合模型顯示3種不同軌跡:低水平和穩定症狀—具恢復力(76.4%)、有新症狀(14.2%)、長期悲痛(9.4%)。與具恢復力的組別相比, 有新症狀與長期悲痛組別可被以下因素預測:負面情緒༏神經質 (機會比例(OR) 分別為 OR = 1.09, 95% CI [1.02, 1.17] 及 OR = 1.22, 95% CI [1.09‐1.35])、和戰鬥經歷 (分別為 OR = 1.07, 95% CI [1.02, 1.12] 及 OR = 1.12, 95% CI [1.02, 1.24])。有新症狀的組別能被以下因素預測:服役前的從軍準備 (OR = 0.95, 95% CI [0.91, 0.98])、服役時的威脅感知 (OR = 1.07, 95% CI [1.03, 1.10])、以及服役後構成壓力的生命事件 (OR = 1.44, 95% CI [1.05, 1.96])。曾前往伊拉克或阿富汗服役 (OR = 3.85, 95% CI [1.72‐8.69])、服役前的抑鬱症 (OR = 1.27, 95% CI [1.20, 1.36])、及服役前憂慮會對家庭與生活構成影響 (OR = 1.09, 95% CI [1.02, 1.16]), 構成長期悲痛軌跡, 使它不同於具恢復力組別。找出樣本服役前使其脆弱的因素與服役後的環境因素, 能有助我們日後提升患者的恢復力, 以及預防和治療創傷後壓力症狀。 Simplified Chinese 标题: 出征伊拉克的美国国民警卫队的恢复力与创伤后压力症状:针对潜在组别轨迹及其预测变量的前瞻性研究 撮要: 本研究透过出征伊拉克战斗的美国国民警卫队样本(N = 522), 检视创伤后压力症(PTSD)症状的前瞻性发展。样本接受了4次评估:于服役前1个月、完成服役归来2至3个月后、1年后和2年后。增长混合模型显示3种不同轨迹:低水平和稳定症状—具恢复力(76.4%)、有新症状(14.2%)、长期悲痛(9.4%)。与具恢复力的组别相比, 有新症状与长期悲痛组别可被以下因素预测:负面情绪༏神经质 (机会比例(OR) 分别为 OR = 1.09, 95% CI [1.02, 1.17] 及 OR = 1.22, 95% CI [1.09‐1.35])、和战斗经历 (分别为 OR = 1.07, 95% CI [1.02, 1.12] 及 OR = 1.12, 95% CI [1.02, 1.24])。有新症状的组别能被以下因素预测:服役前的从军准备 (OR = 0.95, 95% CI [0.91, 0.98])、服役时的威胁感知 (OR = 1.07, 95% CI [1.03, 1.10])、以及服役后构成压力的生命事件 (OR = 1.44, 95% CI [1.05, 1.96])。曾前往伊拉克或阿富汗服役 (OR = 3.85, 95% CI [1.72‐8.69])、服役前的抑郁症 (OR = 1.27, 95% CI [1.20, 1.36])、及服役前忧虑会对家庭与生活构成影响 (OR = 1.09, 95% CI [1.02, 1.16]), 构成长期悲痛轨迹, 使它不同于具恢复力组别。找出样本服役前使其脆弱的因素与服役后的环境因素, 能有助我们日后提升患者的恢复力, 以及预防和治疗创伤后压力症状。