Suicidality is an important contributor to disease burden worldwide. We examine the developmental and environmental correlates of reported suicidal ideation at age 15 and develop a new evolutionary model of suicidality based on life history trade-offs and hypothesized accompanying modulations of cognition. Data were derived from the National Longitudinal Survey of Children and Youth (Statistics Canada) which collected information on children’s social, emotional, and behavioral development in eight cycles between 1994 and 2009. We take a model selection approach to understand thoughts of suicide at age 15 (N ≈ 1,700). The most highly ranked models include social support, early life psychosocial stressors, prenatal stress, and mortality cues. Those reporting consistent early life stress had 2.66 greater odds of reporting thoughts of suicide at age 15 than those who reported no childhood stress. Social support of the primary caregiver, neighborhood cohesion, nonkin social support of the adolescent, and the number of social support sources are all associated with suicidal thoughts, where greater neighborhood cohesion and social support sources are associated with a reduction in experiencing suicidal thoughts. Mother’s prenatal smoking throughout pregnancy is associated with a 1.5 greater odds of suicidal thoughts for adolescents compared to children whose mother’s reported not smoking during pregnancy. We discuss these findings in light of evolutionary models of suicidality. This study identifies both positive and negative associations on suicidal thoughts at age 15 and considers these in light of adaptive response models of human development. Findings are relevant for mental health policy.

自杀是全世界疾病负担的一个重要因素。我们研究了 15 岁时报告的自杀意念的发展和环境相关性，并根据生活史权衡和假设的伴随认知调节开发了一种新的自杀进化模型。数据来自全国儿童和青少年纵向调查（加拿大统计局），该调查收集了 1994 年至 2009 年间八个周期中儿童社交、情感和行为发展的信息。我们采用模型选择方法来了解 15 岁时的自杀想法（N ≈ 1,700）。排名最高的模型包括社会支持、早期生活心理社会压力、产前压力和死亡线索。那些自称有持续的早期生活压力的人在 15 岁时报告自杀想法的几率比那些自称没有童年压力的人高出 2.66。主要照顾者的社会支持、邻里凝聚力、青少年的非亲属社会支持以及社会支持来源的数量都与自杀念头相关，其中更大的邻里凝聚力和社会支持来源与自杀念头的减少相关。与母亲报告在怀孕期间不吸烟的儿童相比，母亲在整个怀孕期间产前吸烟与青少年自杀念头的几率增加 1.5 倍有关。我们根据自杀的进化模型讨论这些发现。这项研究确定了 15 岁时自杀想法的积极和消极关联，并根据人类发展的适应性反应模型来考虑这些关联。研究结果与心理健康政策相关。