The process of scientific validation of the ICD-11 Clinical Descriptions and Diagnostic Requirements (CDDR) for Mental Disorders has spanned more than 10 years, being remarkably comprehensive and inclusive as well as truly international, with the involvement of many hundreds of clinicians and researchers from all regions of the world.

The field trials of the ICD-11 CDDR – contrary to those of the ICD-10 Clinical Descriptions and Diagnostic Guidelines (CDDG) and the DSM-5 diagnostic criteria – have been genuinely “developmental” (as opposed to “summative” or “evaluative”) in their nature¹. That is, they have been conducted before the finalization of the relevant sets of criteria or guidelines – thus allowing the identification of conceptual or terminological problems in the proposed texts, the correction of those texts, and the further testing of the revised versions – rather than being conducted or concluded after the finalization of the relevant sets of criteria or guidelines, thus just providing information to clinicians about what they could expect from those products. As we will see, several amendments to the CDDR were actually implemented as a consequence of this design.

The CDDR field trials can be subdivided into two main groups: a) Internet-based trials, implemented through the Global Clinical Practice Network (involving, at the time when the trials were conducted, more than 15,000 mental health and primary health care professionals from more than 150 countries), which used a case vignette methodology to assess the effects of specific differences between the CDDR and the ICD-10 CDDG on the participants’ clinical decision making; b) clinic-based (or ecological) trials, assessing the reliability and clinical utility of the CDDR in real clinical contexts. The clinic-based trials differed from the DSM-5 field trials in that they used a joint-rater design (with two clinicians jointly interviewing each patient) rather than a test-retest design (with two clinicians separately interviewing each patient at different time points), thus controlling for information variance and more specifically testing the reliability of the proposed guidelines (rather than testing more generally the reliability of the relevant psychiatric diagnoses)².

Among the Internet-based CDDR field trials, of special interest have been those focusing on disorders specifically associated with stress³, and on feeding and eating disorders⁴. A case-control field trial on the former grouping of disorders³, conducted with 1,738 mental health professionals from 76 countries, found that several changes introduced in the ICD-11 – including the addition of complex post-traumatic stress disorder (complex PTSD) and prolonged grief disorder – resulted in significantly improved diagnostic decisions. However, the trial also identified some problems with the proposed CDDR text (including difficulties with interpretation of the “re-experiencing” criterion for the PTSD diagnosis, and in differentiating prolonged grief disorder from normal bereavement), which led to a revision and further validation of the text.

Similarly, a case-control field trial on feeding and eating disorders⁴, conducted with 2,288 mental health professionals representing all world regions, found that the changes introduced in the ICD-11 CDDR improved the diagnostic accuracy and clinical utility compared to the ICD-10 CDDG. However, the trial also identified difficulties in determining whether a person with a diagnosis of anorexia nervosa was recovered, as well as problems in the identification of binge eating episodes, which led to a refinement of the definition of recovery for anorexia nervosa and to the specification that the subjective experience of loss of control over eating and related distress is a pathognomonic feature of binge eating even when the amount of food consumed is not objectively large.

Among the clinic-based CDDR field trials, the largest one – conducted among 1,806 patients in 13 countries and focusing on mental disorders which account for the greatest proportion of global disease burden (schizophrenia and other primary psychotic disorders, mood disorders, anxiety and fear-related disorders, and disorders specifically associated with stress) found that intraclass kappa coefficients for diagnoses ranged from 0.45 (for dysthymic disorder) to 0.88 (for social anxiety disorder), and could be considered moderate to almost perfect for all diagnoses, with an overall reliability superior for the CDDR compared to the ICD-10 CDDG². The same trial also found that the CDDR were perceived as easy to use, corresponding accurately to patients’ presentations, clear and understandable, providing an appropriate level of detail, taking about the same or less time than clinicians’ usual practice, and providing useful guidance about the distinction of each disorder from normality and from other disorders⁵.

The somewhat long period of time elapsed between the production of the first draft and the finalization of the CDDR has also allowed an extensive and detailed validation of some of the categories newly introduced in the ICD-11. Emblematic in this respect has been the validation of the new categories of prolonged grief disorder and complex PTSD.

According to a PubMed search performed on February 8, 2024, the papers with original data published since 2013 on prolonged grief disorder have been 57. Overall, they documented the construct validity of the new category, its differentiation from other disorders (e.g., depression and PTSD); its association with marked functional impairment (beyond the effects of concomitant disorders); and its higher consistency with patterns of prolonged grief in longitudinal studies compared to DSM-5 persistent complex bereavement disorder. This evidence has led to the inclusion of prolonged grief disorder in the DSM-5-TR⁶.

A PubMed search performed on the same date detected 199 papers with original data published since 2013 on complex PTSD. Overall, they documented the validity of the new category, and its differentiation from PTSD in a wide range of cultures, in children and adolescents as well as in adults, and across several traumatized populations⁷. This research has been facilitated by the development and validation – prompted by the circulation of the CDDR drafts – of a new specific assessment instrument, the International Trauma Questionnaire.

A further significant difference between the ICD-11 CDDR and the DSM-5 diagnostic criteria which has been tested internationally is that concerning the classification of severe irritability in children and adolescents. A study conducted with 196 clinicians from 48 countries⁸ found that the formulation proposed in the CDDR (using chronic irritability-anger as a specifier for the diagnosis of oppositional defiant disorder) led to a more accurate identification of severe irritability and a better differentiation from boundary presentations compared to both the DSM-5 solution (introducing the new category of disruptive mood dysregulation disorder) and the ICD-10 classification (listing oppositional defiant disorder as one of several conduct disorders without attention to irritability). Participants using the DSM-5 often failed to apply the diagnosis of disruptive mood dysregulation disorder when it was required, whereas they more often applied a psychiatric diagnosis to irritability that was normative in relation to the developmental stage.

One more innovative aspect of the process of validation of the ICD-11 CDDR has been the systematic involvement of experts by experience, through an international study (INCLUDE) conducted in India, the UK and the US⁹. This study collected users’ input on five diagnoses: depressive episode, generalized anxiety disorder, schizophrenia, bipolar I disorder, and personality disorder. Overall, the CDDR were in many cases perceived as useful and relevant to lived experience.

Of course, a currently missing key element in the scientific validation of the CDDR is their performance in ordinary clinical practice. The ongoing efforts to translate them in as many languages as possible, to widely disseminate them, and to accelerate their endorsement and implementation by national governments, will be crucial in this respect, and a regular update of the text (every two years)⁷, to be performed on this basis, is already being planned.

ICD-11 精神障碍临床描述和诊断要求 (CDDR) 的科学验证过程已历时 10 多年，非常全面、包容性强，而且真正具有国际性，来自世界各地的数百名临床医生和研究人员参与其中。世界所有地区。

ICD-11 CDDR 的现场试验——与 ICD-10 临床描述和诊断指南 (CDDG) 以及 DSM-5 诊断标准相反——是真正的“发展性”（而不是“总结性”或“评估性”） ”) 本质上¹ .也就是说，它们是在相关标准或指南最终确定之前进行的，从而可以识别拟议文本中的概念或术语问题，更正这些文本，并对修订版本进行进一步测试，而不是在相关标准或指南最终确定后进行或结束，因此只是向临床医生提供有关他们对这些产品的期望的信息。正如我们将看到的，由于这种设计，实际上对 CDDR 进行了几项修订。

CDDR 现场试验可分为两大类： a) 基于互联网的试验，通过全球临床实践网络实施（试验进行时，涉及来自多个国家的 15,000 多名心理健康和初级卫生保健专业人员）超过 150 个国家），使用案例小插图方法来评估 CDDR 和 ICD-10 CDDG 之间的具体差异对参与者临床决策的影响； b) 基于临床（或生态）的试验，评估 CDDR 在真实临床环境中的可靠性和临床实用性。基于临床的试验与 DSM-5 现场试验的不同之处在于，它们采用联合评估者设计（两名临床医生共同采访每位患者），而不是重测设计（两名临床医生在不同时间点分别采访每位患者） ），从而控制信息方差并更具体地测试拟议指南的可靠性（而不是更普遍地测试相关精神病学诊断的可靠性） ² 。

在基于互联网的 CDDR 现场试验中，特别感兴趣的是那些关注与压力特别相关的疾病³以及喂养和饮食失调^{4 的}试验。对来自 76 个国家的 1,738 名精神卫生专业人员进行的一项针对前一组疾病的病例对照现场试验³发现，ICD-11 中引入了一些变化，包括增加了复杂的创伤后应激障碍（复杂的 PTSD）和长期悲伤障碍——导致诊断决策显着改善。然而，该试验也发现了拟议的 CDDR 文本的一些问题（包括解释 PTSD 诊断的“重新体验”标准的困难，以及区分长期悲伤障碍与正常丧亲之痛的困难），这导致了修订和进一步验证的文本。

同样，一项针对喂养和饮食失调^{4 的}病例对照现场试验，由代表世界各地区的 2,288 名精神卫生专业人员进行，发现与 ICD-10 相比，ICD-11 CDDR 中引入的变化提高了诊断准确性和临床实用性CDDG。然而，该试验还发现了确定神经性厌食症诊断患者是否康复的困难，以及识别暴食发作的问题，这导致对神经性厌食症康复的定义和规范进行了细化即使客观上消耗的食物量并不大，对饮食失去控制和相关痛苦的主观体验也是暴食的一个特征。

在基于临床的 CDDR 现场试验中，规模最大的一项在 13 个国家的 1,806 名患者中进行，重点关注占全球疾病负担比例最大的精神障碍（精神分裂症和其他原发性精神障碍、情绪障碍、焦虑和恐惧）相关疾病和与压力特别相关的疾病）发现，诊断的类内 kappa 系数范围为 0.45（心境恶劣障碍）到 0.88（社交焦虑障碍），并且可以认为所有诊断都中等至几乎完美，总体可靠性与 ICD-10 CDDG ²相比，CDDR 更优越。同一项试验还发现，CDDR 被认为易于使用，与患者的表现准确对应，清晰易懂，提供适当的详细程度，花费与临床医生通常实践相同或更少的时间，并提供有用的指导关于每种疾病与正常疾病和其他疾病的区别⁵ ．

从初稿的制定到 CDDR 的定稿之间经历了一段较长的时间，这也使得 ICD-11 中新引入的一些类别得到了广泛而详细的验证。在这方面具有代表性的是对长期悲伤障碍和复杂创伤后应激障碍（PTSD）新类别的验证。

根据 2024 年 2 月 8 日进行的 PubMed 搜索，自 2013 年以来发表的有关长期悲伤障碍的原始数据论文有 57 篇。总体而言，他们记录了新类别的构建有效性及其与其他疾病（例如抑郁症和抑郁症）的区别。创伤后应激障碍）；其与明显的功能障碍的关联（超出伴随疾病的影响）；与 DSM-5 持续性复杂丧亲障碍相比，它与纵向研究中的长期悲伤模式具有更高的一致性。这一证据导致将长期悲伤障碍纳入 DSM-5-TR ⁶ 。

同日进行的 PubMed 检索发现了 199 篇论文，其中包含自 2013 年以来发表的有关复杂 PTSD 的原始数据。总体而言，他们记录了新类别的有效性，以及它与多种文化中的创伤后应激障碍（PTSD）的区别，包括儿童、青少年以及成人，以及几个受创伤的人群⁷ 。这项研究得到了新的具体评估工具——国际创伤问卷——的开发和验证（CDDR 草案的流通推动）的推动。

ICD-11 CDDR 和已在国际上测试过的 DSM-5 诊断标准之间的另一个显着差异是关于儿童和青少年严重烦躁的分类。一项对来自 48 个国家 196 名临床医生进行的研究⁸发现，CDDR 中提出的表述（使用慢性烦躁-愤怒作为诊断对立违抗性障碍的说明符）可以更准确地识别严重烦躁，并更好地区分边界与 DSM-5 解决方案（引入破坏性情绪失调障碍的新类别）和 ICD-10 分类（将对立违抗障碍列为几种行为障碍之一，而不关注易激惹）进行比较。使用 DSM-5 的参与者常常未能在需要时应用破坏性情绪失调障碍的诊断，而他们更经常将精神科诊断应用于与发育阶段相关的规范性易激惹。

ICD-11 CDDR 验证过程的一个更具创新性的方面是，通过在印度、英国和美国进行的一项国际研究 (INCLUDE)，经验丰富的专家系统地参与其中⁹ 。这项研究收集了用户对五种诊断的意见：抑郁症、广泛性焦虑症、精神分裂症、I型双相情感障碍和人格障碍。总体而言，CDDR 在许多情况下被认为是有用的并且与生活经验相关。

当然，目前 CDDR 科学验证中缺少的一个关键要素是它们在普通临床实践中的表现。在这方面，持续努力将其翻译成尽可能多的语言、广泛传播并加速各国政府的认可和实施将至关重要，并且定期更新文本（每两年） ⁷ ，在此基础上开展的工作，已经在规划之中。