研究背景和目的

医学难以解释的躯体症状或功能性躯体综合征常见于综合医院门诊患者。为统一该组疾病的诊疗管理，《精神疾病诊断与统计手册》第五版（Diagnostic and Statistical Manual of Mental Disorders, fifth edition, DSM-5）引入躯体症状障碍 (somatic symptom disorder, SSD) 的概念，并强调了躯体症状相关心理行为特征的重要性。同一时期，Fink等人提出躯体不适综合征 (bodily distress syndrome, BDS）旨在统一诊断大多数功能性症状和疾病。SSD患者常常首诊于非精神心理科，目前对不同临床背景下SSD的差异知之甚少。精神专科领域内，SSD常常与焦虑、抑郁共病，临床上存在鉴别、诊疗困难的问题。SSD呈慢性迁延病程，本身具有躯体症状-情绪-行为等一系列问题交织的复杂性，当前研究多聚焦于SSD横断面特征或药物/心理干预效果。

因此，本研究旨在探讨SSD与BDS的分布特征及临床测量学差异，分析不同科室（现代生物医学科、中医科与心身医学科）SSD患者的临床特点及诊断工具截断值的异同，鉴别SSD与抑郁障碍（major depressive disorder, MDD）、广泛性焦虑障碍（general anxiety disorder, GAD）临床心理学特征上的差异，观察SSD患者躯体症状、情绪及行为8周随访时的变化规律。

研究方法

本研究包括四部分内容：第一部分是多中心横断面研究，连续入组北京、上海、成都、武汉、晋城等地区九所三甲医院的门诊患者。患者来自三种不同的临床背景，包括现代生物医学科（消化内科/神经科）、中医科和心身医学科。分别通过 DSM-5 临床定式检查-研究版（DSM-5 versions of the Structured Clinical Interview, SCID-5）、BDS-25检查表联合功能性躯体障碍和健康焦虑研究访谈 （Research Interview for Functional Somatic Disorders and Health Anxiety, RIFD）进行SSD和BDS的诊断评估。通过躯体症状障碍诊断B标准量表（Somatic Symptom Disorder–B Criteria Scale, SSD-12）、患者健康问卷躯体症状群量表（Patient Health Questionnaire-15, PHQ-15）、患者健康问卷抑郁量表（Patient Health Questionnaire-9, PHQ-9）、广泛性焦虑量表（7-items generalized anxiety disorder scale, GAD-7）、12项健康调查简表（Short-Form Health Survey, SF-12）评价患者躯体症状相关精神痛苦、躯体症状严重程度、抑郁水平、焦虑水平和健康质量。第二部分，研究样本同第一部分，通过SSD-12、PHQ-15、PHQ-9、GAD-7评估不同科室SSD患者的临床特征。第三部分，分别连续入组北京协和医院心理医学科门诊就诊的SSD、MDD和GAD患者，所有患者均经过简明国际神经精神访谈（Mini-International Neuropsychiatric Interview, MINI 7.0.2）完善诊断评估，通过SSD-12、PHQ-15、PHQ-9、GAD-7评估临床症状，通过人格功能水平量表-简表2.0 (Level of Personality Functioning Scale–Brief Form 2.0, LPFS-BF 2.0)、述情障碍问卷 (Toronto Alexithymia Scale, TAS-26)、防御方式问卷 (Defense Style Questionnaire, DSQ) 评估心理学特征。第四部分为单样本队列研究，在精神科门诊连续入组首次发作的SSD患者。研究者邀请其完成MINI诊断访谈及基线和8周后两次问卷填写，并记录入组后的治疗情况。通过SSD-12、PHQ-15、PHQ-9、GAD-7及附加问题（每天专注于症状本身的时间、过去一月就医次数、症状对生活的影响、患病归因）评估患者的躯体症状、情绪及行为。

研究结果

第一部分共有694名门诊患者完成临床结构化访谈和调查问卷。

同时符合SSD和BDS诊断的患者有126名（年龄：42.60 ± 14.51；女性：65.9%），只符合SSD诊断的患者有109名（年龄：43.38 ± 13.58；女性：54.1%），只符合BDS者60名（年龄：40.92 ± 14.80；女性：58.3%），两诊断均不符合者399名（年龄：43.15 ± 14.27；女性：62.4%）。符合SSD诊断患者中，53.6%（126/235）符合BDS诊断；符合BDS诊断患者中，67.7%（126/186）符合SSD诊断；SSD和BDS间存在中度重叠（kappa = 0.43）。四组患者社会人口学和生活方式特征方面无明显统计学差异。
只符合SSD诊断者SSD-12得分更高，只符合BDS诊断者PHQ-15得分更高。
与既不符合SSD也不符合BDS诊断的患者和只符合SSD或只符合BDS诊断的患者相比，同时符合SSD和BDS诊断的患者明显表现出更高的躯体症状相关心理困扰（SSD-12）、躯体症状严重程度（PHQ-15）、抑郁（PHQ-9）和焦虑（GAD-7）水平，以及更低的精神和躯体健康质量（SF-12）；符合任何一种诊断的患者都比两种诊断均不符合的患者表现出更严重的躯体、心理和生活质量损害。

2. 第二部分的研究样本同第一部分，现代生物医学科、中医科、心身医学科入组的患者分别为224、231、239名。其中，符合SSD诊断的患者分别为90、44、101名。

1) 生物医学科、中医科和心身医学科中，SSD检出率分别为40.2%、19.0%和42.3%，且差异具有统计学意义（c2 = 34.153, p ≤ 0.001）。

2) 三个科室符合SSD诊断患者PHQ-15、PHQ-9、GAD-7评分差异具有统计学意义（p < 0.05），心身医学科SSD患者PHQ-15、PHQ-9、GAD-7得分显著高于现代生物医学科（p < 0.05）。三个科室SSD患者SSD-12评分没有明显统计学差异。

3) 现代生物医学科、中医科和心身医学科SSD患者与非SSD患者临床测量学特征比较，SSD-12、PHQ-15、PHQ-9、GAD-7评分差异均具有统计学意义（p < 0.05）。

4) 不同科室SSD患者躯体症状（PHQ-15）分析显示，中医科SSD患者月经问题明显多于现代生物医学科，心身医学科SSD患者头痛、胸痛和性交痛/问题比现代生物医学科SSD患者更常见（p < 0.05）。其他症状无显著差异。

5) 现代生物医学科、中医科和心身医学科，SSD-12诊断SSD的截断值分别为16、16和17分；PHQ-15诊断SSD的截断值分别为8、9、11。

3. 第三部分共招募患者165例，包括SSD55例、MDD55例、GAD55例。

1）临床症状方面，三组患者SSD-12、PHQ-9、GAD-7得分存在显著差异（p < 0.05），PHQ-15得分无显著差异。具体来说，SSD组SSD-12得分显著高于MDD组和GAD组；SSD组GAD-7得分显著低于MDD组和GAD组（p < 0.05）；MDD组PHQ-9得分显著高于SSD组和GAD组（p < 0.05）。

2）心理学特征方面，三组患者LPFS-BF2.0、TAS-26、不成熟防御机制、中间型防御机制得分存在显著差异（p < 0.05），成熟防御机制得分无显著差异。SSD组LPFS-BF2.0总分、自我功能和人际功能得分显著低于MDD组、GAD组 (p < 0.05)；SSD组TAS-26总分、描述情感的能力因子得分、认识和区分情感与躯体感受的能力因子得分显著低于MDD组 (p < 0.05)，SSD组认识和区分情感与躯体感受的能力因子得分、外向性思维因子得分显著低于GAD组 (p < 0.05)；SSD组不成熟防御机制均分显著低于MDD组和GAD组 (p < 0.05)。

3）自我功能、认识和区分情感与躯体感受的能力、不成熟防御机制对SSD-12具有显著正向预测作用；TAS-26总分、认识和区分情感与躯体感受的能力、不成熟防御机制对PHQ-15具有显著正向预测作用；LPFS-BF2.0总分、自我功能对PHQ-9具有显著正向预测作用；LPFS-BF2.0总分、自我功能、幻想对GAD-7具有显著正向预测作用。

4. 第四部分，共招募SSD患者42人，完成研究者35人。

1）19人入组前曾接受药物或心理治疗，8周随访期内25人接受药物治疗，9人接受心理治疗，5人同时接受药物治疗和心理治疗，6人未接受药物/心理治疗。

2）8周后SSD患者各项结果（躯体症状相关精神痛苦、躯体症状严重程度、抑郁水平、焦虑水平、每日专注于症状的时间、过去一月的就医次数、症状对生活的影响）均较前显著下降，多数患者由躯体归因转为心理归因，且不受患者基线治疗情况的影响。

结论：

SSD和BDS的检出率存在中度重叠，SSD与BDS可能反映不同的精神病理——SSD更关注心理困扰，而BDS更侧重躯体症状本身。同时满足两种诊断的患者心理社会多维损伤更为突出。
心身医学科SSD患者较中医科与现代生物医学科表现出更严重的躯体症状、抑郁及焦虑水平。本研究中，不同临床背景下SSD-12筛查的截断值相对稳定（统一为 ≥ 16分），使用PHQ-15筛查SSD患者时应注意不同临床背景下应用的截断值不同: 现代生物医学科、中医科及心身医学科分别建议为 ≥ 8分、≥ 9分和 ≥ 11分。
SSD是独立于MDD、GAD的精神障碍，躯体症状相关的心理行为特征是SSD的重要标志。述情障碍、人格功能水平、防御机制等跨诊断心理特征是连接三种疾病的重要因素，总的来说，MDD、GAD患者上述跨诊断心理特征的损伤较SSD更为突出。
随访中大部分患者积极接受治疗，且总体症状-情绪-行为改善，SSD早诊断、早治疗是重要的。

Background and objective:

Medically unexplained somatic symptoms or functional somatic syndromes are commonly seen in outpatients of general hospitals. In order to unify the diagnosis and treatment management of this group of diseases, the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) introduces the concept of somatic symptom disorder (SSD) and emphasizes the importance of psycho-behavioral characteristics associated with somatic symptoms. At the same time, Fink et al. proposed bodily distress syndrome (BDS) to uniformly diagnose most functional symptoms and diseases. Patients with SSD are often first visited to non-psychiatric departments, and little is known about the differences in SSD in different clinical settings. In the field of psychiatry, SSD is often comorbidities with anxiety and depression, and there are problems in clinical diagnosis and treatment. SSD presents a chronic and protracted disease course, which itself is complicated by a series of intertwined problems such as physical symptoms, emotions and behaviors. Current studies mostly focus on the cross-sectional characteristics of SSD or the effects of drug/psychological intervention.

Therefore, this study aims to explore the distribution characteristics and psychometric differences between SSD and BDS, analyze differences in clinical features of SSD patients across different settings (modern biomedical departments, traditional Chinese medicine, and psychosomatic settings) and variations in diagnostic tool cutoff values, compare clinical and psychological characteristics among SSD, Major Depressive Disorder (MDD), and Generalized Anxiety Disorder (GAD), and observe changes in somatic symptoms, emotions, and behaviors in SSD patients over an 8-week follow-up.

Methods: 

This study includes four parts: The first part is a multi-center cross-sectional study, which continuously enrolled outpatients from nine first-class hospitals in Beijing, Shanghai, Chengdu, Wuhan, Jincheng and other areas. The patients come from three different clinical backgrounds, including modern biomedical (gastroenterology/neurology), Traditional Chinese medicine, and psychosomatic medicine. DSM-5 Versions of the Structured Clinical Interview (SCID-5) and BDS-25 check list combined with Research Interview for Functional Somatic Disorders and Health Anxiety (RIFD) was used to the diagnostic evaluation of SSD and BDS, respectively. According to Somatic Symptom Disorder - B Criteria Scale (SSD-12), Patient Health Questionnaire-15 (PHQ-15), Patient Health Questionnaire-9 (PHQ-9), 7-items generalized anxiety disorder scale (GAD-7), 12 Short-Form Health Survey (SF-12) evaluated somatic symptom-related mental distress, somatic symptom severity, depression level, anxiety level, and health status. In the second part, the study samples were the same as the first part, and the clinical characteristics of patients were evaluated by SSD-12, PHQ-15, PHQ-9, and GAD-7. In the third part, SSD, MDD, and GAD patients were successively enrolled in the outpatient department of Psychological Medicine of Peking Union Medical College Hospital. All patients underwent MINI diagnostic interview, and their clinical symptoms were evaluated by SSD-12, PHQ-15, PHQ-9, and GAD-7. Level of Personality Functioning Scale - Brief Form 2.0 (LPFS-BF 2.0), the Toronto Alexithymia Scale (TAS-26), and the Defense Style Questionnaire (DSQ) were used to assess psychological characteristics. The fourth part is a single-sample cohort study, which continuously enrolled patients with first episode of SSD in psychiatric outpatient department. They were invited to complete the MINI diagnostic interview and two questionnaires at baseline and 8 weeks later, and their treatment status was recorded after enrollment. Physical symptoms, mood, and behavior were assessed by SSD-12, PHQ-15, PHQ-9, GAD-7, and additional questions (time per day to focus on symptoms themselves, visits to the doctor in the past month, impact of symptoms on life, and attribution of illness).

Results:

1. The first part is based on a secondary analysis of data from 694 outpatients who completed clinical structured interviews and questionnaires.

1) SSD and BDS had a moderate overlap (kappa value = 0.43). Among them, 126 (Age: 42.60±14.51; Female: 65.9%) met the criteria of both diagnoses, 109 (Age: 43.38±13.58; Female: 54.1%) met the criteria of only SSD, 60 (Age: 40.92±14.80; Female: 58.3%) met the criteria of only BDS, and 399 (Age: 43.15±14.27; Female: 62.4%) met the criteria of neither SSD nor BDS. Of patients meeting SSD criteria, 53.6% (126/235) met BDS criteria. Of patients diagnosed with BDS, 67.7% (126/186) met SSD criteria. There were no significant differences in socio-demographic and lifestyle characteristics among the four groups.

2) Patients who only met SSD had higher SSD-12 scores, whereas those with only BDS had higher PHQ-15 scores (p < 0.001).

3) Patients who fulfilled both SSD and BDS showed significantly higher levels of symptom-related psychological distress (SSD-12), somatic symptom severity (PHQ-15), depression (PHQ-9), general anxiety (GAD-7), as well as lower mental and physical quality of life (SF-12) compared to patients who met neither SSD nor BDS diagnosis and patients who met only SSD or BDS diagnosis.

4) Patients with either diagnosis showed more severe physical, psychological and quality of life impairment than those with neither diagnosis.

2. In the second part of the study, 90 out of 224 participants in biomedical settings, 44 out of 231 participants in TCM departments, and 101 out of 239 participants in psychosomatic departments were diagnosed with SSD.

1）The prevalence of SSD was 40.2, 19.0 and 42.3% in the biomedical, TCM and psychosomatic settings, respectively. The differences were significant (χ2 = 34.153, p ≤ 0.001).

2) Significant differences in scores of PHQ-15, PHQ-9 and GAD-7 were identified between patients diagnosed with SSD in the biomedical, TCM and psychosomatic settings (p < 0.05). The scores of PHQ-15, PHQ-9 and GAD-7 were significantly higher among SSD patients in psychosomatic departments than that in biomedical settings (p < 0.05). However, no difference was found in SSD-12 scores among patients with SSD in the biomedical, TCM and psychosomatic settings.

3) There were significant differences in scores of SSD-12, PHQ-15, PHQ-9, and GAD-7 between patients with and without SSD in the modern biomedical settings, TCM departments and psychosomatic medicine departments, respectively (p < 0.05).

4) The physical symptom profile of SSD patients in different settings were analyzed and the result showed that patients in the TCM departments reported significantly more menstrual problems than patients in biomedical settings (p < 0.05), and headaches, chest pain and pain or problems during sexual intercourse were more common in psychosomatic settings than in biomedical settings (p < 0.05). No significant differences were observed in terms of other symptoms.

5) The cutoff point for SSD-12 were found to be 16, 16, 17 in biomedical, TCM and psychosomatic settings, respectively; the cutoff point for PHQ-15 were found to be 8, 9, 11 in biomedical, TCM and psychosomatic settings, respectively.

3. In the third part, a total of 165 patients were recruited, including 55 patients with SSD, 55 patients with MDD and 55 patients with GAD.

1）In terms of clinical symptoms, there were significant differences in SSD-12, PHQ-9 and GAD-7 scores among the three groups (p < 0.05), but no significant differences in PHQ-15 scores. Specifically, the score of SSD-12 in SSD group was significantly higher than that in MDD group and GAD group; the score of GAD-7 in SSD group was significantly lower than that in MDD group and GAD group; the PHQ-9 score of MDD group was significantly higher than that of SSD group and GAD group (p < 0.05).

2) In terms of psychological characteristics, there were significant differences in the scores of LPFS-BF2.0, TAS-26, immature and intermediate defense mechanisms among the three groups (p < 0.05), but no significant differences in the scores of mature defense mechanisms. The total score of LPFS-BF2.0, self-functioning and interpersonal functioning in SSD group were significantly lower than those in MDD group and GAD group (p < 0.05); The total score of TAS-26, the score of ability to describe emotion, and the score of ability to recognize and distinguish emotion and body feeling in SSD group were significantly lower than those in MDD group (p < 0.05), and the score of ability to recognize and distinguish emotion and body feeling and extroversion thinking factor in SSD group were significantly lower than those in GAD group (p < 0.05). The mean score of immature defense mechanisms in SSD group was significantly lower than that in MDD group and GAD group (p < 0.05).

3）Self-functioning, ability to recognize and distinguish between emotion and body sensation, and immature defense mechanisms had significant positive predictive effect on SSD-12. The total score of TAS-26, the ability to recognize and distinguish between emotion and body sensation, and immature defense mechanisms had significant positive predictive effect on PHQ-15. LPFS-BF2.0 total score and self-functioning had significant positive predictive effect on PHQ-9. LPFS-BF2.0 total score, self-functioning and fantasy have significant positive predictive effect on GAD-7.

4. In the fourth part, a total of 42 SSD patients were recruited and 35 completed.

1) 19 participants received medication or psychotherapy before enrollment, 25 received medication, 9 received psychotherapy, 5 received both medication and psychotherapy, and 6 did not receive medication/psychotherapy during the 8-week follow-up period.

2) After 8 weeks, all outcomes (somatic symptom-related mental distress, severity of physical symptoms, depression level, anxiety level, time spent focusing on symptoms per day, visits to the doctor in the past month, and impact of symptoms on life) in the present study were significantly lower than before, and most patients switched from somatic to psychological attribution, independent of the baseline treatment.

Conclusions:

1. SSD and BDS appear to represent somewhat different psychopathologies, with SSD more associated with psychological distress and BDS associated with greater experience of somatic symptoms. Patients fulfilling both diagnosis show higher symptom severity in various psychosocial aspects.

2. SSD patients from psychosomatic departments had higher level of somatic symptom severity, depression and anxiety than from TCM and biomedical settings. In our specific sample, a cutoff point of ³ 16 for SSD-12 could be recommended in all three settings. But the cutoff point of PHQ-15 differs much between different settings, which was ³ 8, 9, and 11 in biomedical, TCM, and psychosomatic settings, respectively.

3. SSD is a distinct psychiatric disorder from MDD and GAD, the psychological and behavioral characteristics related to somatic symptoms are important signs of SSD. Somatic symptoms, anxiety/depression severity, and transdiagnostic psychological traits serve as critical links among these conditions.

4. During the follow-up, most of the patients actively accepted the treatment, and the overall symptom-emotion-behavior improved. Thus, early diagnosis and treatment of SSD are important.