Complex traumas are traumatic experiences that involve multiple interpersonal threats during childhood or adolescence, such as repeated abuse. These traumas are hypothesised to cause more severe psychopathology and poorer cognitive function than other non-complex traumas. However, empirical testing has been limited to clinical/convenience samples and cross-sectional designs.

To investigate psychopathology and cognitive function in young people exposed to complex, non-complex or no trauma, from a population-representative longitudinal cohort, and to consider the role of pre-existing vulnerabilities.

Participants were from the Environmental Risk Longitudinal Twin Study, a population-representative birth cohort of 2232 British children. At age 18 years (93% participation), we assessed lifetime exposure to complex and non-complex trauma, past-year psychopathology and current cognitive function. We also prospectively assessed early childhood vulnerabilities: internalising and externalising symptoms at 5 years of age, IQ at 5 years of age, family history of mental illness, family socioeconomic status and sex.

Participants exposed to complex trauma had more severe psychopathology and poorer cognitive function at 18 years of age, compared with both trauma-unexposed participants and those exposed to non-complex trauma. Early childhood vulnerabilities predicted risk of later complex trauma exposure, and largely explained associations of complex trauma with cognitive deficits, but not with psychopathology.

By conflating complex and non-complex traumas, current research and clinical practice underestimate the severity of psychopathology, cognitive deficits and pre-existing vulnerabilities linked with complex trauma. A better understanding of the mental health needs of people exposed to complex trauma could inform the development of new, more effective interventions.

复杂的创伤是一种创伤经历，涉及童年或青春期的多种人际威胁，例如反复虐待。假设这些创伤比其他非复杂创伤会导致更严重的精神病理学和更差的认知功能。然而，经验测试仅限于临床/便利样本和横断面设计。

从具有代表性的人群纵向队列中研究暴露于复杂、非复杂或无创伤的年轻人的精神病理学和认知功能，并考虑预先存在的脆弱性的作用。

参与者来自环境风险纵向双胞胎研究，这是一个由 2232 名英国儿童组成的具有人口代表性的出生队列。在 18 岁时（93% 的参与），我们评估了终生暴露于复杂和非复杂创伤、过去一年的精神病理学和当前的认知功能。我们还前瞻性地评估了儿童早期的脆弱性：5 岁时的内化和外化症状、5 岁时的智商、精神疾病家族史、家庭社会经济地位和性别。

与未暴露于创伤的参与者和暴露于非复杂创伤的参与者相比，暴露于复杂创伤的参与者在 18 岁时具有更严重的精神病理学和较差的认知功能。儿童早期的脆弱性预示着后来复杂创伤暴露的风险，并在很大程度上解释了复杂创伤与认知缺陷的关联，但与精神病理学无关。

通过将复杂和非复杂创伤混为一谈，当前的研究和临床实践低估了与复杂创伤相关的精神病理学、认知缺陷和预先存在的脆弱性的严重性。更好地了解遭受复杂创伤的人的心理健康需求可以为开发新的、更有效的干预措施提供信息。