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Somatic symptoms vary in major depressive disorder in China
Comprehensive Psychiatry 87 (2018) 32–37
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Somatic symptoms vary in major depressive disorder in China☆ Dongmei Zhao a,b,1, Zhiguo Wu a,1, Huifeng Zhang a, David Mellor c, Lei Ding a, Haiyan Wu a, Chuangxin Wu a, Jia Huang a, Wu Hong a, Daihui Peng a,⁎, Yiru Fang a,d,e,⁎⁎ a
Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, No.600, South Wanping Road, Xuhui District, 200030 Shanghai, PR China Shanghai Changning Mental Health Center, No 229, Xiehe Road, Changning District, Shanghai 200042, PR China School of Psychology, Deakin University, Melbourne, Australia d Shanghai Key Laboratory of Psychotic Disorders, PR China e CAS Center for Excellence in Brain Science and Intelligence Technology, PR China b c
a r t i c l e
i n f o
Available online xxxx
a b s t r a c t Purpose: This study aimed to investigate the clinical characteristics of somatic symptoms of patients in China who suffer from major depressive disorder (MDD). Method: 3273 patients who met the diagnostic criteria of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) MDD were recruited from 16 general hospitals and 16 mental health centers in China. Physicians and patients completed complementary customized depression disorder symptomatology questionnaires assessing the clinical characteristics of patients with MDD. Result: 1. In this study we analyzed physician-recorded data. The major somatic symptoms in patients with MDD in China were insomnia (64.6%), pre-verbal physical complaints (46.9%), weight loss (38.5%), low appetite (37.6%), circulatory system complaints (31.3%), headache (31.3%), hyposexuality (31.0%), gastrointestinal symptom complaints (29.6%), and respiratory system complaints (29.6%). 2. Compared with MDD patients who sought medical help from mental health centers, MDD patients who sought medical help from general hospitals were more likely to suffer from urinary system complaints, headache, sensory system complaints, trunk pain, and nervous system complaints. A lower prevalence rate of insomnia and hyposexuality was also observed among MDD patients who visited general hospitals (p b .05). 3. Patients aged from 40 to 54 had the highest probability of pre-verbal physical complaints, respiratory system complaints, trunk pain, hyposexuality, limb pain and other pain conditions, while patients over 55 years of age had the lowest prevalence respiratory system complaints, hyposexuality, and other pain conditions, and they also had the highest rate of low appetite and insomnia. 4. Female patients appeared to exhibit higher rates of pre-verbal physical complaints, low appetite, and insomnia than male patients, but had fewer urinary systems complaints than male patients (p b .05). Conclusion: The major somatic symptoms in patients with MDD in China are insomnia, pre-verbal physical complaints, weight loss, low appetite, circulatory system complaints, headache, hyposexuality, gastrointestinal system complaints, and respiratory system complaints. These symptoms vary by the type of medical setting to which patients present, and well as by age, and gender. © 2018 Elsevier Inc. All rights reserved.
Currently, the prevalence rate of MDD is 4.4% worldwide [1] and 3.02% in China [2]. According to the World Health Organization (WHO), MDD ranks third in the list of burden of disease. By 2020, it is ☆ Funding: The National Key Research and Development Program of China 2016YFC1307100, 2016YFC0906400; Shanghai Jiao Tong University Foundation YG2015MS47; Shanghai Hospital Development Center Foundations SHDC12015131, SHDC12015302; The National Natural Science Foundation of China 81571327. ⁎ Corresponding author. ⁎⁎ Correspondence to: Y. Fang, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, No.600, South Wanping Road, Xuhui District, 200030 Shanghai, PR China. E-mail addresses: [email protected] (D. Peng), [email protected] (Y. Fang). 1 Co-first author: Dongmei Zhao, Zhiguo Wu.
https://doi.org/10.1016/j.comppsych.2018.08.013 0010-440X/© 2018 Elsevier Inc. All rights reserved.
expected to be the second heaviest burden after heart disease [3], and by 2030, it will account for the biggest portion of the global disease burden [4]. In China, due to the limited mental health resources and the social stigma associated with mental illness, many MDD patients with somatic symptoms such as stomachache or headache choose to visit general hospitals and this leads to missed diagnosis of their depression, and consequently missed opportunities for appropriate treatment [2]. In 1983, Wilson suggested that though somatic symptoms were not regarded as clinical diagnostic criteria of MDD, such symptoms both preceded and pararalled MDD in patients presenting at a family practice most of time [5]. In line with this, a systematic review of 70 studies conducted in European countries found a high comorbidity between painful physical symptoms and depressive symptoms in three populations:
D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
general populations, patients presenting to their general practitioner (GP), and patients treated at specialist pain clinics or psychiatric clinics. In many studies patients with MDD were reported to have presented for treatment because of somatic complaints rather than depression [6]. Over half of depressed patients experienced painful somatic symptoms, and somatic symptoms associated with depressive and anxious symptoms [7]. In China, where people tend to express physical discomfort instead of admitting to having depression symptoms [8,9], research has also revealed that over half of MDD patients believe that they have physical diseases rather than a mental illness [10]. Similarly, other research across 14 countries and 15 primary health care centers has shown that between 45 and 90% of MDD patients complained mainly about their somatic symptoms, indicating that somatic symptoms may be a core component of the clinical features of MDD [11]. Given that somatic symptoms seem to be often comorbid with MDD and the major focus of patients, somatization might be an early symptom of MDD, and an effective indicator for early diagnosis of MDD [12]. Research suggests that the severity of somatic symptoms is the most powerful indicator of MDD patients' prognosis [13]. A prospective study of 909 Chinese MDD patients found a positive correlation between somatic symptoms and severity of depression symptoms, while a negative correlation between somatic symptoms and remission rate has also been observed [14]. Somatic symptoms play a key role in emotion and decision-making process in MDD. However, to date, somatic symptoms have not been carefully studied in relation to the clinical diagnosis and treatment of MDD [15]. A research showed that Chinese people were more likely to consider some psychological symptoms such as “thinking life is not worth living” as the typical features for people with depression, rather than somatic features such as “sleep disturbance” [16]. It indicated that the somatic symptoms varied in MDD [17]. To analyze the clinical features of somatic symptoms of MDD patients, our study utilized data gathered in an epidemiological survey of major depression disorder in Chinese mental health centers and general hospitals conducted in 2014. 1. Subjects and method 1.1. Subjects From August 2014 to February 2015, 3516 patients were recruited from 16 psychiatric hospitals and 16 general hospitals across 7 administrative areas in mainland China. Approvals were gained from the ethics committee of each site, and all the patients signed consent forms. 1.2. Inclusion and exclusion criteria Inclusion criteria: (a) Age ≥ 16; (b) meeting the DSM-IV TR diagnostic criteria for MDD; (c) condition not well-controlled (HRSD reduction rate ≤ 50%) after maximum dose of antidepressants and full course of treatment (≤8 weeks). Exclusion criteria: (a) patients with suicide risks; (b) bipolar disorder; (c) patients who had received Modified Electra convulsive Therapy (MECT) treatment within one month; (d) females in pregnancy and/or lactating period. 1.3. Evaluation measures The National Survey on Symptomatology of Depression (NSSD) was designed to explore the severity of symptoms of MDD across a widespread symptomatology within and outside DSM framework. Due to the combined meaning of some diagnostic criteria, we divided a total of 9 sets of DSM symptoms into 20 separate items. Other 44 symptoms covered somatic, emotional, cognitive, anxious, interpersonal and other domains of MDD. Symptoms in other domains included diurnal changes, self-harm behavior, psychotic symptoms, as well as culturespecific symptoms like centrality of sleeplessness, distress of social
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disharmony and pre-verbal physical complaints, which are common complaints by MDD in Chinese clinics and have been found to be significant in previous reports and being focused strongly by patients [18]. Because of the high prevalence of anxious depression in Chinese MDD patients [19,20] and high tendency to express somatic symptoms than psychological symptoms [9,21,22], we emphasized the assessment on anxious and somatic symptoms. The somatic symptoms included, besides diagnostic symptoms like changes in appetite, sleeping problems, weight loss, painful physical symptoms. The NSSD was constructed based on the following materials. (a) Diagnostic criteria: The DSM-IV, International Classification of diseases (ICD-10), and the Chinese Classification of Mental Disorders, 3rd version (CCMD-3). (b) Depression and anxiety rating scales like Montgomery-Asberg Depression Rating Scale (MADRS), Hamilton Rating Scale for Depression (HRSD), Quick Inventory of Depressive Symptomatology (QIDS), the Patient Health Questionnaires (PHQ-9 and PHQ-15), Hamilton Anxiety Scale (HAMA), Self-Rating Depression Scale (SDS), and Self-Rating Anxiety Scale (SAS). According to previous researches, those all have good reliability and validity among Chinese populations [23–26]. (c) Various of literatures examining classic description and clinical manifestation of MDD from Chinese textbooks, which represent views of Chinese top experts' on the important symptoms and signs of depression, as well as English textbooks (e.g., The American Psychiatric Publishing Textbook of Psychiatry, fifth edition) with Chinese translation. The symptoms of NSSD were discussed by a consultant group composed of 10 psychiatrists who have extensive expertise in psychiatric clinics and researches on depression in China. An article on clinical characteristics associated with therapeutic nonadherence of depression patients using NSSD was already published [27]. Each version of the questionnaire assesses 16 somatic symptoms: (1) Pre-verbal physical complaints; (2) Respiratory system complaints, including shortness of breath, suffocation, and respiratory distress; (3) Circulation system complaints, including chest tightness, flustered symptoms, and feeling of vessel beat; (4) Low appetite; (5) Urinary system complaints, including frequent urination and urgent urination; (6) Insomnia; (7) Limb pain; (8) Gastrointestinal system complaints, including discomfort in stomach and intestines; (9) Trunk pain; (10) Weight loss; (11) Headache; (12) Sensory system complaints, including allergy, skin chill, skin fever or skin discomfort; (13) Nervous system complaints, including dizziness, tinnitus, and sweating; (14) Hyposexuality; (15) Muscular system complaints, including muscular tightness, aches and twitching; (16) Other pain conditions. Weight reduction was divided into two levels (1 = yes, 2 = not at all). Other symptoms are divided into 4 levels: 1 = not at all, 2 = few time, 3 = most time, 4 = almost every day. Evaluators of the questionnaire (physician version) were required to be registered physicians. The questionnaire (patient version) was filled in independently according to the patient's subjective feelings. In this paper we report on the analyses of physician questionnaire data. 1.4. Statistical analysis SPSS23 was used for analyses of the NSSD questionnaire (physician version) data. Responses 1 and 2 (not at all and few time) were considered as asymptomatic, whereas 3 and 4 (most time and almost everyday) were taken as symptomatic. Fisher's z test of proportions and chi-square tests were used to examine associations among categorical data. 2. Results 2.1. Demographic data We recruited 3516 patients with MDD, but data from 243 were not included in the analyses because their questionnaires were not
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D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
2.3. Comparison of MDD somatic symptoms in different institutions
Table 1 General demographic data of MDD patients.
Gender
Age
Degree of education
Employment status
Receiving institution Visiting way
Male Female Missing data 16–39 40–54 ≥55 Below bachelor's degree Bachelor's degree or equivalence Graduate degree or higher Missing data Currently employed Student Unemployed Retired Missing data Psychiatric hospitals General hospitals Out-patient department In-patient department Missing data
Number (N)
Percentage (%)
1292 1973 8 1653 1040 580 1841 1187
39.6 60.4
115 130 1782 200 748 444 99 1806 1467 2393 876 8
We tested for differences in somatic symptomatology according to the type of institution at which patients sought help (see Table 2). We used Fisher's z-test to compare two proportion, using a significance level of 0.05, 2-tailed test. Those who visited general hospitals had a higher prevalence of urinary system complaints (z = 2.1, p = .0359), headache (z = 2.5, p = .0141), sensory system complaints (z = 2.3, p = .0207), trunk pain (z = 2, p = .0453), and nervous symptom complaints (z = 2.8, p = .0059) than patients who presented at psychiatric hospitals. In contrast, the prevalence rates of insomnia (z = 2.4, p = .0148) and hyposexuality (z = 2.9, p = .0039) were lower among patients who sought help at psychiatric hospitals.
50.5 31.8 17.7 58.6 37.8 3.6 56.1 6.3 23.6 14.0
2.4. Somatic symptoms of patients with MDD in different age ranges
55.2 44.8 73.2 26.8
complete. Of the remaining 3273 patients, 1292 were male patients, 1973 were female patients, and for 8 patients gender was not recorded. Patients' average age was 41.27 ± 13.33. For the purposes of analysis related to age, we divided the sample into three groups: 16–39 years (N = 1653), 40–54 years (N = 1040) and 55 years+ (N = 580). Other demographic data are summarized in Table 1. As also shown in Table 1, 2393 patients were out-patients, and 876 patients were in-patients. Such data were not recorded for 8 patients. Finally, 1806 patients were recruited from psychiatric hospitals and 1467 from general hospitals.
2.2. Prevalence rate of various somatic symptoms in MDD patients The prevalence of each of the 16 somatic symptoms among the 3273 MDD patients is summarized in Fig. 1 below. As can be seen, insomnia was the most common somatic symptom, present in 64.6% of the patients. Urinary system complaints were the least common, present in 15.9% of the patients.
Chi-square tests revealed significant age effects for eight MDD somatic symptoms. Patients from 40 to 54 years old had the highest prevalence of pre-verbal physical complaints (51.5%), respiratory system complaints (33.0%), trunk pain (29.4%), hyposexuality (34.5%), limb pain (27.9%) and other pain conditions (28.6%) than the other two age groups. Patients who are older than 55 appear to have the lowest prevalence rate of respiratory symptom complaints (25.2%), hyposexuality (24.0%), limb pain (20.9%) and other pain conditions (23.1%), but they also have the highest prevalence rates for low appetite (41.6%) and insomnia (71.5%). After Chi-square tests, there are 8 somatic symptoms have difference in 3 age groups, each symptom needs to be compared 3 times, to avoid the first-order-error, We adjust the α value, use the Bonferroni-correction, α = 0.05/3 = 0.0167. Then we used Fisher's ztest to compare pairwise the 3 age groups, using a significance level of 0.0167, 2-tailed test. The difference in pre-verbal physical complaint between age 1 and age 2 have significant difference. The difference in respiratory system complaints between age 2 and age 3 has significant difference. The difference in low appetite is only significant between age 2 and age 3. The difference in insomnia between age 1 and age 2, age 1 and age 3 are significant. The difference in trunk pain between age 1 and age 2 have significant difference. The difference of hyposexuality between age 2 and age 3, age 1 and age 3 are significant, no significant difference between age 1 and age 2. The difference in other pain conditions between age 1 and age 2, age 2 and age 3 are significant, no significant difference between age 1 and ages 3. The
64.6% 46.9% 38.5% 37.6% 31.3% 31.3% 31.0% 29.6% 29.6% 26.9% Incidence rate of various 25.3% somac symptoms 25.2% 25.2% 24.1% 20.8% 15.9%
Insomnia Pre-verbal physical complaints Weight loss Low appete Circulatory system complaints Headache Hyposexuality Gastrointesnal system complaints Respiratory system complaints Nervous system complaints Trunk pain Other pain condions Muscular system complaints Limb pain Sensory system complaints Urinary system complaints 0
0.1
0.2
0.3
0.4
0.5
Fig. 1. The prevalence rate of somatic symptoms in depression.
0.6
0.7
0.8
D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
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Table 2 Comparison of MDD somatic symptoms between general hospitals and psychiatric hospitals.
Urinary system complaints Insomnia Headache Sensory system complaints Trunk pain Nervous system complaints Hyposexuality Pre-verbal physical complaints Respiratory system complaints Circulation system complaints Low appetite Gastrointestinal system complaints Weight loss Muscular system complaints Other pain conditions Limb pain
General hospital (n = 1467) n1, n1/(n-n2)
95%CI
Psychiatric hospitals (n = 1806) n1, n1/(n-n2)
95%CI
Difference 95%CI
z value
p value
254(17.4%) 913(62.3%) 492(33.5%) 331(22.6%) 395(27.0%) 429(29.3%) 414(28.4%) 668(45.8%) 458(31.3%) 469(32.1%) 535(36.5%) 438(29.9%) 567(38.9%) 355(24.3%) 367(25.1%) 360(24.5%)
0.1546–0.1934 0.5982–0.6478 0.3108–0.3592 0.2046–0.2474 0.2473–0.2927 0.2697−0.3163 0.2608–0.3072 0.4324–0.4836 0.2892–0.3368 0.2971–0.3449 0.3403–0.3897 0.2756–0.3224 0.364–0.414 0.2201–0.2639 0.2288–0.2732 0.223–0.267
264(14.7%) 119(66.4%) 532(29.5%) 348(19.3%) 429(23.9%) 451(25.0%) 596(33.1%) 862(47.8%) 510(28.3%) 552(30.6%) 693(38.5%) 528(29.3%) 688(38.2%) 469(26.0%) 455(25.2%) 428(23.7%)
0.1307–0.1633 0.6422–0.6858 0.274–0.316 0.1748–0.2112 0.2193–0.2587 0.23–0.27 0.3093–0.3527 0.4549–0.5011 0.2622–0.3038 0.2847–0.3273 0.3625–0.4075 0.272–0.314 0.3596–0.4044 0.2398–0.2802 0.232–0.272 0.2174–0.2566
0.0018–0.0522 0.008–0.074 0.008–0.0719 0.005–0.061 0.001–0.0609 0.0124–0.0736 0.0151–0.0789 −0.0144–0.0544 −0.0015–0.0615 −0.017–0.047 −0.0134–0.0534 −0.0255–0.0375 −0.0266–0.0406 −0.0119–0.0479 −0.0289–0.0309 −0.0214–0.0374
2.1 2.4 2.5 2.3 2 2.8 2.9 1.1 1.9 0.9 1.2 0.4 0.4 1.2 0.1 0.5
.0359 .0148 .0141 .0207 .0453 .0059 .0039 .2551 .0619 .3581 .2406 .7086 .6831 .2385 .9478 .5944
n: all participants; n1:participants with symptom; n2:participants with missing data.
difference of limb pain between age 2 and age 3, age 1 and age 2, no significant difference between age 1 and age 3 (Table 3). 2.5. Comparison of MDD somatic symptoms between genders We used Fisher's z-test to compare proportions of male and female patients with various somatic symptomatologies. Female patients with MDD exhibited a higher probability of having pre-verbal physical complaints (z = 2.1, p = .0386), low appetite (z = 3.5, p = .0004), and insomnia (z = 3.1, p = .0020) than male patients, and a lower prevalence of urinary symptom complaints than male patients (z = 4.7, p b .0001) (Table 4). 3. Discussion Our study utilized data gathered from a 2014 epidemiological survey of major depression disorder in Chinese psychiatric hospitals and general hospitals, to investigate the prevalence rates of various somatic symptoms among MDD patients. We also analyzed how age and gender are related to the occurrence of somatic symptoms.
Our results indicate that the top three somatic symptoms among Chinese MDD patient are in order of frequency, insomnia (64.6%), preverbal physical complaints (46.9%), and weight loss (38.5%). MDD patients who visit general hospitals have higher prevalence of headache, trunk pain, urinary system complaints, sensory system complaints, and nervous system complaints than patients who visit mental health centers, while the frequency of insomnia and hyposexuality is higher in patients who visit mental health centers. The results correspond with those of previous research in China which reported that the rate of diagnosis of MDD patients with somatic symptoms was considerably higher in general hospitals and that those patients had relatively higher prevalence of abdominal ache, dizziness, headache, chest tightness, appetite reduction, and debilitation [28–30]. Similarly, international studies have indicated that common somatic symptoms of patients with MDD during treatment in primary care institutions were low appetite, palpitation, headache, difficulty in breath, trunk pain, muscular tightness, and back pain [31,32]. However, patients with MDD who visit general hospitals and primary care institutions often deny their mental symptoms and only present with somatic symptoms such as palpitation, debilitation, or trunk pain [6,10,12,33–35]. Previous research in
Table 3 Comparison of MDD somatic symptoms in different age ranges.
Pre-verbal physical complaints Respiratory system complaints Low appetite Insomnia Trunk pain Hyposexuality Other pain conditions Limb pain Circulation system complaints Urinary system complaints Gastrointestinal system complaints Weight loss Headache Sensory system complaints Nervous system complaints Muscular system complaints
Age = 1a (n = 1653) n1, n1/(n-n2)
Age = 2b (n = 1040) n1, n1/(n-n2)
Age = 3c (n = 580) n1, n1/(n-n2)
χ2
pd
Bonferroni group comparisone
718(43.5%) 480(29.1%) 628(38.1%) 994(60.2%) 381(23.1%) 516(31.3%) 391(23.7%) 377(22.8%) 492(29.8%) 265(16.1%) 502(30.4%) 643(39.1%) 517(31.3%) 333(20.2%) 420(25.4%) 391(23.7%)
534(51.5%) 342(33.0%) 359(34.6%) 702(67.6%) 305(29.4%) 356(34.5%) 297(28.6%) 290(27.9%) 346(33.4%) 168(16.2%) 297(28.6%) 394(38.1%) 331(31.8%) 225(21.6%) 293(28.2%) 287(27.6%)
278(48.3%) 146(25.2%) 241(41.6%) 414(71.5%) 138(23.9%) 138(24.0%) 134(23.1%) 121(20.9%) 183(31.8%) 85(14.7%) 167(28.8%) 218(37.7%) 176(30.3%) 121(20.9%) 167(28.9%) 146(25.3%)
16.689 11.255 7.952 29.925 14.059 19.415 9.616 13.092 3.864 0.686 1.131 0.490 0.381 0.859 3.884 5.251
b.001 .004 .019 b.001 b.001 b.001 .008 b.001 .145 .710 .568 .783 .827 .651 .143 .072
bNa bNc cNb b,c N a bNa a,b N c b N a,c b N a,c – – – – – – – –
n: all participants; n1: participants with symptom; n2:participants with missing data; –: no significant difference. a Age = 1 (age ≤ 39). b Age = 2 (age: 40–54). c Age = 3 (age ≥ 55). d Use Chi-square test to compare the differences between the three groups (significant level p b .05). e Use Fisher's z-test, Bonferroni-correction (significant level p b .0167) to compare pairwise among three groups.
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D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
Table 4 Comparison of MDD somatic symptoms between genders.
Pre-verbal physical complaints Low appetite Urinary system complaints Insomnia Respiratory system complaints Circulation system complaints Gastrointestinal system complaints Trunk pain Weight loss Headache Sensory system complaints Nervous system complaints Hyposexuality Muscular system complaints Other pain conditions Limb pain
Male (n = 1292) n1, n1/(n-n2)
95%CI
Female (n = 1973) n1, n1/(n-n2)
95%CI
Difference 95%CI
z value
p value
575(44.7%) 436(33.9%) 252(19.6%) 792(61.4%) 372(28.8%) 404(31.4%) 386(29.9%) 330(25.6%) 472(36.7%) 412(31.9%) 259(20.1%) 345(26.8%) 412(32.0%) 341(26.4%) 326(25.3%) 327(25.3%)
0.4198–0.4742 0.3131–0.3649 0.1743–0.2177 0.5874–0.6406 0.2633–0.3127 0.2886–0.3394 0.274–0.324 0.2322–0.2798 0.3407–0.3933 0.2936–0.3444 0.1791–0.2229 0.2438–0.2922 0.2945–0.3455 0.2399–0.2881 0.2293–0.2767 0.2293–0.2767
952(48.4%) 788(40.0%) 266(13.5%) 1313(66.7%) 595(30.2%) 616(31.3%) 578(29.4%) 493(25.1%) 779(39.7%) 610(30.9%) 419(21.3%) 535(27.2%) 594(30.3%) 482(24.5%) 496(25.2%) 460(23.3%)
0.4619–0.5061 0.3784–0.4216 0.1199–0.1501 0.6462–0.6878 0.2817–0.3223 0.2925–0.3335 0.2739–0.3141 0.2318–0.2702 0.3754–0.4186 0.2886–0.3294 0.1949–0.2311 0.2523–0.2917 0.2827–0.3233 0.226–0.264 0.2328–0.2712 0.2143–0.2517
0.0019–0.0721 0.027–0.095 0.0353–0.0867 0.0194–0.0866 −0.018–0.0461 −0.0316–0.0336 −0.027–0.037 −0.0255–0.0355 −0.0042–0.0642 −0.0225–0.0425 −0.0165–0.0405 −0.0272–0.0352 −0.0155–0.0495 −0.0115–0.0495 −0.0295–0.0315 −0.01–0.05
2.1 3.5 4.7 3.1 0.9 0.1 0.3 0.3 1.7 0.6 0.8 0.3 1 1.2 0.1 1.3
.0386 .0004 b.0001 .0020 .3921 .9521 .7597 .7483 .0857 .5468 .4092 .8013 .3054 .2221 .9488 .1913
n: all participants; n1: participants with symptom; n2: participants with missing data.
China investigating the clinical features of MDD in China have been geographically restricted and included only patients from either psychiatric hospitals or general hospitals. Subjects in our research were recruited from both general hospitals and psychiatric hospitals, and demonstrated a discrepancy in somatic symptoms of MDD patients who visit different types of institutions. Previous research shows that the prevalence of MDD varies across age. Among people of t 18 to 39 years, 40 to 54 years, and N55 years are 1.15%, 2.72%, and 3.82%, respectively [36]. We divided our subjects into three age groups: b39, 40–54, and ≥ 55 and found that compared to patients in the other two age groups, MDD patients aged between 40 and 54 had the highest occurrence of pre-verbal physical complaints (51.5%), respiratory system complaints (33.0%), trunk pain (29.4%), hyposexuality (34.5%), limb pain (27.9%) and other pain conditions (28.6%). Meanwhile, patients who are beyond 55 years of age exhibited the lowest prevalence of respiratory system complaints (25.2%), hyposexuality (24.0%), and other pain conditions (23.1%), while they also have the highest rate of having low appetite (41.6%) and insomnia (71.5%). Previous domestic research suggests that elderly patients with MDD show increased prevalence of body complaints [37–39]. Other international studies suggest that patients with MDD express somatic complaints more frequently as age increases [8,40–43]. On the other hand other studies have reported that MDD patients beyond 60 years of age have no worse somatic symptoms than other MDD patients [44] or that few somatic symptoms are found in MDD patients over 70 years of age [45]. One investigation of MDD and anxiety disorders associated with somatic symptoms among Chinese patients found that patients who were between 35 and 44 years of age old had the highest severity level of somatic symptoms [46]. Overall then, the results of our study are inconsistent with some studies, and in agreement with others. The differences may be due to different age stratification and participant numbers in age groups. Our research indicates that Chinese young adults who suffer MDD have as similar or even higher levels of somatic symptoms as elderly patients. To understand whether this result is unique to China or the Chinese culture more generally, further research is required. Epidemiologic data from China shows that the lifetime prevalence of MDD among females is twice that of males [26]. The adjusted prevalence for males is 1.55% and for female it is 2.60% [36]. International studies also report that the prevalence of somatic symptoms among female patients with MDD is higher than for male patients [47], specifically in appetite reduction and insomnia [48]. Our research suggests that for patients with MDD, gender mainly makes a difference in somatic symptoms such as pre-verbal physical complaints, low appetite, insomnia, and urinary system complaints. Except for urinary system
complaints, the other three symptoms have higher prevalence rate in female group. Research interview data from the USA National Comorbidity Survey, with a representative nationwide sample, revealed that women were much more likely than men to report clinical depression associated with appetite and sleep disturbances and fatigue, labeled “somatic depression” [47,49]. Depression associated with such somatic symptoms is more prevalent in females than males, and this may underlie the different prevalence rates for MDD for males and females [50]. It has therefore been suggested that if somatic symptoms were factored out, the prevalence of MDD would be the same for each gender [51]. Our investigation suggests somatic depression among females may involve different pathogenesis, so there should be some changes in treatment plans. Our study has some limitations. First, the sample sizes in different age groups varied considerably. Second, as we only analyzed physician reported data, self-reported patient data needs in-depth analysis. Our research group will continue to investigate if there exists differences between self-evaluation of patients and evaluation gathered by physicians. Somatic symptoms, being independent of psychiatric characteristics, physical diseases, and life styles, can be a predictive factor that affects prognosis. Somatic symptoms also have negative consequences for the course of MDD [52]. Patients with MDD who have somatic symptoms may conceal the core symptoms of depression which results in low recognition rate and delayed treatment. Somatic symptoms that MDD patients report should be carefully considered and treated, but not to the neglect of the depressive symptoms. In the future, patients with somatic symptoms should be followed up to discover the reason why prevalence varies in different age ranges and across gender. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi. org/10.1016/j.comppsych.2018.08.013.
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Comprehensive Psychiatry journal homepage: www.elsevier.com/locate/comppsych
Somatic symptoms vary in major depressive disorder in China☆ Dongmei Zhao a,b,1, Zhiguo Wu a,1, Huifeng Zhang a, David Mellor c, Lei Ding a, Haiyan Wu a, Chuangxin Wu a, Jia Huang a, Wu Hong a, Daihui Peng a,⁎, Yiru Fang a,d,e,⁎⁎ a
Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, No.600, South Wanping Road, Xuhui District, 200030 Shanghai, PR China Shanghai Changning Mental Health Center, No 229, Xiehe Road, Changning District, Shanghai 200042, PR China School of Psychology, Deakin University, Melbourne, Australia d Shanghai Key Laboratory of Psychotic Disorders, PR China e CAS Center for Excellence in Brain Science and Intelligence Technology, PR China b c
a r t i c l e
i n f o
Available online xxxx
a b s t r a c t Purpose: This study aimed to investigate the clinical characteristics of somatic symptoms of patients in China who suffer from major depressive disorder (MDD). Method: 3273 patients who met the diagnostic criteria of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) MDD were recruited from 16 general hospitals and 16 mental health centers in China. Physicians and patients completed complementary customized depression disorder symptomatology questionnaires assessing the clinical characteristics of patients with MDD. Result: 1. In this study we analyzed physician-recorded data. The major somatic symptoms in patients with MDD in China were insomnia (64.6%), pre-verbal physical complaints (46.9%), weight loss (38.5%), low appetite (37.6%), circulatory system complaints (31.3%), headache (31.3%), hyposexuality (31.0%), gastrointestinal symptom complaints (29.6%), and respiratory system complaints (29.6%). 2. Compared with MDD patients who sought medical help from mental health centers, MDD patients who sought medical help from general hospitals were more likely to suffer from urinary system complaints, headache, sensory system complaints, trunk pain, and nervous system complaints. A lower prevalence rate of insomnia and hyposexuality was also observed among MDD patients who visited general hospitals (p b .05). 3. Patients aged from 40 to 54 had the highest probability of pre-verbal physical complaints, respiratory system complaints, trunk pain, hyposexuality, limb pain and other pain conditions, while patients over 55 years of age had the lowest prevalence respiratory system complaints, hyposexuality, and other pain conditions, and they also had the highest rate of low appetite and insomnia. 4. Female patients appeared to exhibit higher rates of pre-verbal physical complaints, low appetite, and insomnia than male patients, but had fewer urinary systems complaints than male patients (p b .05). Conclusion: The major somatic symptoms in patients with MDD in China are insomnia, pre-verbal physical complaints, weight loss, low appetite, circulatory system complaints, headache, hyposexuality, gastrointestinal system complaints, and respiratory system complaints. These symptoms vary by the type of medical setting to which patients present, and well as by age, and gender. © 2018 Elsevier Inc. All rights reserved.
Currently, the prevalence rate of MDD is 4.4% worldwide [1] and 3.02% in China [2]. According to the World Health Organization (WHO), MDD ranks third in the list of burden of disease. By 2020, it is ☆ Funding: The National Key Research and Development Program of China 2016YFC1307100, 2016YFC0906400; Shanghai Jiao Tong University Foundation YG2015MS47; Shanghai Hospital Development Center Foundations SHDC12015131, SHDC12015302; The National Natural Science Foundation of China 81571327. ⁎ Corresponding author. ⁎⁎ Correspondence to: Y. Fang, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, No.600, South Wanping Road, Xuhui District, 200030 Shanghai, PR China. E-mail addresses: [email protected] (D. Peng), [email protected] (Y. Fang). 1 Co-first author: Dongmei Zhao, Zhiguo Wu.
https://doi.org/10.1016/j.comppsych.2018.08.013 0010-440X/© 2018 Elsevier Inc. All rights reserved.
expected to be the second heaviest burden after heart disease [3], and by 2030, it will account for the biggest portion of the global disease burden [4]. In China, due to the limited mental health resources and the social stigma associated with mental illness, many MDD patients with somatic symptoms such as stomachache or headache choose to visit general hospitals and this leads to missed diagnosis of their depression, and consequently missed opportunities for appropriate treatment [2]. In 1983, Wilson suggested that though somatic symptoms were not regarded as clinical diagnostic criteria of MDD, such symptoms both preceded and pararalled MDD in patients presenting at a family practice most of time [5]. In line with this, a systematic review of 70 studies conducted in European countries found a high comorbidity between painful physical symptoms and depressive symptoms in three populations:
D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
general populations, patients presenting to their general practitioner (GP), and patients treated at specialist pain clinics or psychiatric clinics. In many studies patients with MDD were reported to have presented for treatment because of somatic complaints rather than depression [6]. Over half of depressed patients experienced painful somatic symptoms, and somatic symptoms associated with depressive and anxious symptoms [7]. In China, where people tend to express physical discomfort instead of admitting to having depression symptoms [8,9], research has also revealed that over half of MDD patients believe that they have physical diseases rather than a mental illness [10]. Similarly, other research across 14 countries and 15 primary health care centers has shown that between 45 and 90% of MDD patients complained mainly about their somatic symptoms, indicating that somatic symptoms may be a core component of the clinical features of MDD [11]. Given that somatic symptoms seem to be often comorbid with MDD and the major focus of patients, somatization might be an early symptom of MDD, and an effective indicator for early diagnosis of MDD [12]. Research suggests that the severity of somatic symptoms is the most powerful indicator of MDD patients' prognosis [13]. A prospective study of 909 Chinese MDD patients found a positive correlation between somatic symptoms and severity of depression symptoms, while a negative correlation between somatic symptoms and remission rate has also been observed [14]. Somatic symptoms play a key role in emotion and decision-making process in MDD. However, to date, somatic symptoms have not been carefully studied in relation to the clinical diagnosis and treatment of MDD [15]. A research showed that Chinese people were more likely to consider some psychological symptoms such as “thinking life is not worth living” as the typical features for people with depression, rather than somatic features such as “sleep disturbance” [16]. It indicated that the somatic symptoms varied in MDD [17]. To analyze the clinical features of somatic symptoms of MDD patients, our study utilized data gathered in an epidemiological survey of major depression disorder in Chinese mental health centers and general hospitals conducted in 2014. 1. Subjects and method 1.1. Subjects From August 2014 to February 2015, 3516 patients were recruited from 16 psychiatric hospitals and 16 general hospitals across 7 administrative areas in mainland China. Approvals were gained from the ethics committee of each site, and all the patients signed consent forms. 1.2. Inclusion and exclusion criteria Inclusion criteria: (a) Age ≥ 16; (b) meeting the DSM-IV TR diagnostic criteria for MDD; (c) condition not well-controlled (HRSD reduction rate ≤ 50%) after maximum dose of antidepressants and full course of treatment (≤8 weeks). Exclusion criteria: (a) patients with suicide risks; (b) bipolar disorder; (c) patients who had received Modified Electra convulsive Therapy (MECT) treatment within one month; (d) females in pregnancy and/or lactating period. 1.3. Evaluation measures The National Survey on Symptomatology of Depression (NSSD) was designed to explore the severity of symptoms of MDD across a widespread symptomatology within and outside DSM framework. Due to the combined meaning of some diagnostic criteria, we divided a total of 9 sets of DSM symptoms into 20 separate items. Other 44 symptoms covered somatic, emotional, cognitive, anxious, interpersonal and other domains of MDD. Symptoms in other domains included diurnal changes, self-harm behavior, psychotic symptoms, as well as culturespecific symptoms like centrality of sleeplessness, distress of social
33
disharmony and pre-verbal physical complaints, which are common complaints by MDD in Chinese clinics and have been found to be significant in previous reports and being focused strongly by patients [18]. Because of the high prevalence of anxious depression in Chinese MDD patients [19,20] and high tendency to express somatic symptoms than psychological symptoms [9,21,22], we emphasized the assessment on anxious and somatic symptoms. The somatic symptoms included, besides diagnostic symptoms like changes in appetite, sleeping problems, weight loss, painful physical symptoms. The NSSD was constructed based on the following materials. (a) Diagnostic criteria: The DSM-IV, International Classification of diseases (ICD-10), and the Chinese Classification of Mental Disorders, 3rd version (CCMD-3). (b) Depression and anxiety rating scales like Montgomery-Asberg Depression Rating Scale (MADRS), Hamilton Rating Scale for Depression (HRSD), Quick Inventory of Depressive Symptomatology (QIDS), the Patient Health Questionnaires (PHQ-9 and PHQ-15), Hamilton Anxiety Scale (HAMA), Self-Rating Depression Scale (SDS), and Self-Rating Anxiety Scale (SAS). According to previous researches, those all have good reliability and validity among Chinese populations [23–26]. (c) Various of literatures examining classic description and clinical manifestation of MDD from Chinese textbooks, which represent views of Chinese top experts' on the important symptoms and signs of depression, as well as English textbooks (e.g., The American Psychiatric Publishing Textbook of Psychiatry, fifth edition) with Chinese translation. The symptoms of NSSD were discussed by a consultant group composed of 10 psychiatrists who have extensive expertise in psychiatric clinics and researches on depression in China. An article on clinical characteristics associated with therapeutic nonadherence of depression patients using NSSD was already published [27]. Each version of the questionnaire assesses 16 somatic symptoms: (1) Pre-verbal physical complaints; (2) Respiratory system complaints, including shortness of breath, suffocation, and respiratory distress; (3) Circulation system complaints, including chest tightness, flustered symptoms, and feeling of vessel beat; (4) Low appetite; (5) Urinary system complaints, including frequent urination and urgent urination; (6) Insomnia; (7) Limb pain; (8) Gastrointestinal system complaints, including discomfort in stomach and intestines; (9) Trunk pain; (10) Weight loss; (11) Headache; (12) Sensory system complaints, including allergy, skin chill, skin fever or skin discomfort; (13) Nervous system complaints, including dizziness, tinnitus, and sweating; (14) Hyposexuality; (15) Muscular system complaints, including muscular tightness, aches and twitching; (16) Other pain conditions. Weight reduction was divided into two levels (1 = yes, 2 = not at all). Other symptoms are divided into 4 levels: 1 = not at all, 2 = few time, 3 = most time, 4 = almost every day. Evaluators of the questionnaire (physician version) were required to be registered physicians. The questionnaire (patient version) was filled in independently according to the patient's subjective feelings. In this paper we report on the analyses of physician questionnaire data. 1.4. Statistical analysis SPSS23 was used for analyses of the NSSD questionnaire (physician version) data. Responses 1 and 2 (not at all and few time) were considered as asymptomatic, whereas 3 and 4 (most time and almost everyday) were taken as symptomatic. Fisher's z test of proportions and chi-square tests were used to examine associations among categorical data. 2. Results 2.1. Demographic data We recruited 3516 patients with MDD, but data from 243 were not included in the analyses because their questionnaires were not
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D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
2.3. Comparison of MDD somatic symptoms in different institutions
Table 1 General demographic data of MDD patients.
Gender
Age
Degree of education
Employment status
Receiving institution Visiting way
Male Female Missing data 16–39 40–54 ≥55 Below bachelor's degree Bachelor's degree or equivalence Graduate degree or higher Missing data Currently employed Student Unemployed Retired Missing data Psychiatric hospitals General hospitals Out-patient department In-patient department Missing data
Number (N)
Percentage (%)
1292 1973 8 1653 1040 580 1841 1187
39.6 60.4
115 130 1782 200 748 444 99 1806 1467 2393 876 8
We tested for differences in somatic symptomatology according to the type of institution at which patients sought help (see Table 2). We used Fisher's z-test to compare two proportion, using a significance level of 0.05, 2-tailed test. Those who visited general hospitals had a higher prevalence of urinary system complaints (z = 2.1, p = .0359), headache (z = 2.5, p = .0141), sensory system complaints (z = 2.3, p = .0207), trunk pain (z = 2, p = .0453), and nervous symptom complaints (z = 2.8, p = .0059) than patients who presented at psychiatric hospitals. In contrast, the prevalence rates of insomnia (z = 2.4, p = .0148) and hyposexuality (z = 2.9, p = .0039) were lower among patients who sought help at psychiatric hospitals.
50.5 31.8 17.7 58.6 37.8 3.6 56.1 6.3 23.6 14.0
2.4. Somatic symptoms of patients with MDD in different age ranges
55.2 44.8 73.2 26.8
complete. Of the remaining 3273 patients, 1292 were male patients, 1973 were female patients, and for 8 patients gender was not recorded. Patients' average age was 41.27 ± 13.33. For the purposes of analysis related to age, we divided the sample into three groups: 16–39 years (N = 1653), 40–54 years (N = 1040) and 55 years+ (N = 580). Other demographic data are summarized in Table 1. As also shown in Table 1, 2393 patients were out-patients, and 876 patients were in-patients. Such data were not recorded for 8 patients. Finally, 1806 patients were recruited from psychiatric hospitals and 1467 from general hospitals.
2.2. Prevalence rate of various somatic symptoms in MDD patients The prevalence of each of the 16 somatic symptoms among the 3273 MDD patients is summarized in Fig. 1 below. As can be seen, insomnia was the most common somatic symptom, present in 64.6% of the patients. Urinary system complaints were the least common, present in 15.9% of the patients.
Chi-square tests revealed significant age effects for eight MDD somatic symptoms. Patients from 40 to 54 years old had the highest prevalence of pre-verbal physical complaints (51.5%), respiratory system complaints (33.0%), trunk pain (29.4%), hyposexuality (34.5%), limb pain (27.9%) and other pain conditions (28.6%) than the other two age groups. Patients who are older than 55 appear to have the lowest prevalence rate of respiratory symptom complaints (25.2%), hyposexuality (24.0%), limb pain (20.9%) and other pain conditions (23.1%), but they also have the highest prevalence rates for low appetite (41.6%) and insomnia (71.5%). After Chi-square tests, there are 8 somatic symptoms have difference in 3 age groups, each symptom needs to be compared 3 times, to avoid the first-order-error, We adjust the α value, use the Bonferroni-correction, α = 0.05/3 = 0.0167. Then we used Fisher's ztest to compare pairwise the 3 age groups, using a significance level of 0.0167, 2-tailed test. The difference in pre-verbal physical complaint between age 1 and age 2 have significant difference. The difference in respiratory system complaints between age 2 and age 3 has significant difference. The difference in low appetite is only significant between age 2 and age 3. The difference in insomnia between age 1 and age 2, age 1 and age 3 are significant. The difference in trunk pain between age 1 and age 2 have significant difference. The difference of hyposexuality between age 2 and age 3, age 1 and age 3 are significant, no significant difference between age 1 and age 2. The difference in other pain conditions between age 1 and age 2, age 2 and age 3 are significant, no significant difference between age 1 and ages 3. The
64.6% 46.9% 38.5% 37.6% 31.3% 31.3% 31.0% 29.6% 29.6% 26.9% Incidence rate of various 25.3% somac symptoms 25.2% 25.2% 24.1% 20.8% 15.9%
Insomnia Pre-verbal physical complaints Weight loss Low appete Circulatory system complaints Headache Hyposexuality Gastrointesnal system complaints Respiratory system complaints Nervous system complaints Trunk pain Other pain condions Muscular system complaints Limb pain Sensory system complaints Urinary system complaints 0
0.1
0.2
0.3
0.4
0.5
Fig. 1. The prevalence rate of somatic symptoms in depression.
0.6
0.7
0.8
D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
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Table 2 Comparison of MDD somatic symptoms between general hospitals and psychiatric hospitals.
Urinary system complaints Insomnia Headache Sensory system complaints Trunk pain Nervous system complaints Hyposexuality Pre-verbal physical complaints Respiratory system complaints Circulation system complaints Low appetite Gastrointestinal system complaints Weight loss Muscular system complaints Other pain conditions Limb pain
General hospital (n = 1467) n1, n1/(n-n2)
95%CI
Psychiatric hospitals (n = 1806) n1, n1/(n-n2)
95%CI
Difference 95%CI
z value
p value
254(17.4%) 913(62.3%) 492(33.5%) 331(22.6%) 395(27.0%) 429(29.3%) 414(28.4%) 668(45.8%) 458(31.3%) 469(32.1%) 535(36.5%) 438(29.9%) 567(38.9%) 355(24.3%) 367(25.1%) 360(24.5%)
0.1546–0.1934 0.5982–0.6478 0.3108–0.3592 0.2046–0.2474 0.2473–0.2927 0.2697−0.3163 0.2608–0.3072 0.4324–0.4836 0.2892–0.3368 0.2971–0.3449 0.3403–0.3897 0.2756–0.3224 0.364–0.414 0.2201–0.2639 0.2288–0.2732 0.223–0.267
264(14.7%) 119(66.4%) 532(29.5%) 348(19.3%) 429(23.9%) 451(25.0%) 596(33.1%) 862(47.8%) 510(28.3%) 552(30.6%) 693(38.5%) 528(29.3%) 688(38.2%) 469(26.0%) 455(25.2%) 428(23.7%)
0.1307–0.1633 0.6422–0.6858 0.274–0.316 0.1748–0.2112 0.2193–0.2587 0.23–0.27 0.3093–0.3527 0.4549–0.5011 0.2622–0.3038 0.2847–0.3273 0.3625–0.4075 0.272–0.314 0.3596–0.4044 0.2398–0.2802 0.232–0.272 0.2174–0.2566
0.0018–0.0522 0.008–0.074 0.008–0.0719 0.005–0.061 0.001–0.0609 0.0124–0.0736 0.0151–0.0789 −0.0144–0.0544 −0.0015–0.0615 −0.017–0.047 −0.0134–0.0534 −0.0255–0.0375 −0.0266–0.0406 −0.0119–0.0479 −0.0289–0.0309 −0.0214–0.0374
2.1 2.4 2.5 2.3 2 2.8 2.9 1.1 1.9 0.9 1.2 0.4 0.4 1.2 0.1 0.5
.0359 .0148 .0141 .0207 .0453 .0059 .0039 .2551 .0619 .3581 .2406 .7086 .6831 .2385 .9478 .5944
n: all participants; n1:participants with symptom; n2:participants with missing data.
difference of limb pain between age 2 and age 3, age 1 and age 2, no significant difference between age 1 and age 3 (Table 3). 2.5. Comparison of MDD somatic symptoms between genders We used Fisher's z-test to compare proportions of male and female patients with various somatic symptomatologies. Female patients with MDD exhibited a higher probability of having pre-verbal physical complaints (z = 2.1, p = .0386), low appetite (z = 3.5, p = .0004), and insomnia (z = 3.1, p = .0020) than male patients, and a lower prevalence of urinary symptom complaints than male patients (z = 4.7, p b .0001) (Table 4). 3. Discussion Our study utilized data gathered from a 2014 epidemiological survey of major depression disorder in Chinese psychiatric hospitals and general hospitals, to investigate the prevalence rates of various somatic symptoms among MDD patients. We also analyzed how age and gender are related to the occurrence of somatic symptoms.
Our results indicate that the top three somatic symptoms among Chinese MDD patient are in order of frequency, insomnia (64.6%), preverbal physical complaints (46.9%), and weight loss (38.5%). MDD patients who visit general hospitals have higher prevalence of headache, trunk pain, urinary system complaints, sensory system complaints, and nervous system complaints than patients who visit mental health centers, while the frequency of insomnia and hyposexuality is higher in patients who visit mental health centers. The results correspond with those of previous research in China which reported that the rate of diagnosis of MDD patients with somatic symptoms was considerably higher in general hospitals and that those patients had relatively higher prevalence of abdominal ache, dizziness, headache, chest tightness, appetite reduction, and debilitation [28–30]. Similarly, international studies have indicated that common somatic symptoms of patients with MDD during treatment in primary care institutions were low appetite, palpitation, headache, difficulty in breath, trunk pain, muscular tightness, and back pain [31,32]. However, patients with MDD who visit general hospitals and primary care institutions often deny their mental symptoms and only present with somatic symptoms such as palpitation, debilitation, or trunk pain [6,10,12,33–35]. Previous research in
Table 3 Comparison of MDD somatic symptoms in different age ranges.
Pre-verbal physical complaints Respiratory system complaints Low appetite Insomnia Trunk pain Hyposexuality Other pain conditions Limb pain Circulation system complaints Urinary system complaints Gastrointestinal system complaints Weight loss Headache Sensory system complaints Nervous system complaints Muscular system complaints
Age = 1a (n = 1653) n1, n1/(n-n2)
Age = 2b (n = 1040) n1, n1/(n-n2)
Age = 3c (n = 580) n1, n1/(n-n2)
χ2
pd
Bonferroni group comparisone
718(43.5%) 480(29.1%) 628(38.1%) 994(60.2%) 381(23.1%) 516(31.3%) 391(23.7%) 377(22.8%) 492(29.8%) 265(16.1%) 502(30.4%) 643(39.1%) 517(31.3%) 333(20.2%) 420(25.4%) 391(23.7%)
534(51.5%) 342(33.0%) 359(34.6%) 702(67.6%) 305(29.4%) 356(34.5%) 297(28.6%) 290(27.9%) 346(33.4%) 168(16.2%) 297(28.6%) 394(38.1%) 331(31.8%) 225(21.6%) 293(28.2%) 287(27.6%)
278(48.3%) 146(25.2%) 241(41.6%) 414(71.5%) 138(23.9%) 138(24.0%) 134(23.1%) 121(20.9%) 183(31.8%) 85(14.7%) 167(28.8%) 218(37.7%) 176(30.3%) 121(20.9%) 167(28.9%) 146(25.3%)
16.689 11.255 7.952 29.925 14.059 19.415 9.616 13.092 3.864 0.686 1.131 0.490 0.381 0.859 3.884 5.251
b.001 .004 .019 b.001 b.001 b.001 .008 b.001 .145 .710 .568 .783 .827 .651 .143 .072
bNa bNc cNb b,c N a bNa a,b N c b N a,c b N a,c – – – – – – – –
n: all participants; n1: participants with symptom; n2:participants with missing data; –: no significant difference. a Age = 1 (age ≤ 39). b Age = 2 (age: 40–54). c Age = 3 (age ≥ 55). d Use Chi-square test to compare the differences between the three groups (significant level p b .05). e Use Fisher's z-test, Bonferroni-correction (significant level p b .0167) to compare pairwise among three groups.
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D. Zhao et al. / Comprehensive Psychiatry 87 (2018) 32–37
Table 4 Comparison of MDD somatic symptoms between genders.
Pre-verbal physical complaints Low appetite Urinary system complaints Insomnia Respiratory system complaints Circulation system complaints Gastrointestinal system complaints Trunk pain Weight loss Headache Sensory system complaints Nervous system complaints Hyposexuality Muscular system complaints Other pain conditions Limb pain
Male (n = 1292) n1, n1/(n-n2)
95%CI
Female (n = 1973) n1, n1/(n-n2)
95%CI
Difference 95%CI
z value
p value
575(44.7%) 436(33.9%) 252(19.6%) 792(61.4%) 372(28.8%) 404(31.4%) 386(29.9%) 330(25.6%) 472(36.7%) 412(31.9%) 259(20.1%) 345(26.8%) 412(32.0%) 341(26.4%) 326(25.3%) 327(25.3%)
0.4198–0.4742 0.3131–0.3649 0.1743–0.2177 0.5874–0.6406 0.2633–0.3127 0.2886–0.3394 0.274–0.324 0.2322–0.2798 0.3407–0.3933 0.2936–0.3444 0.1791–0.2229 0.2438–0.2922 0.2945–0.3455 0.2399–0.2881 0.2293–0.2767 0.2293–0.2767
952(48.4%) 788(40.0%) 266(13.5%) 1313(66.7%) 595(30.2%) 616(31.3%) 578(29.4%) 493(25.1%) 779(39.7%) 610(30.9%) 419(21.3%) 535(27.2%) 594(30.3%) 482(24.5%) 496(25.2%) 460(23.3%)
0.4619–0.5061 0.3784–0.4216 0.1199–0.1501 0.6462–0.6878 0.2817–0.3223 0.2925–0.3335 0.2739–0.3141 0.2318–0.2702 0.3754–0.4186 0.2886–0.3294 0.1949–0.2311 0.2523–0.2917 0.2827–0.3233 0.226–0.264 0.2328–0.2712 0.2143–0.2517
0.0019–0.0721 0.027–0.095 0.0353–0.0867 0.0194–0.0866 −0.018–0.0461 −0.0316–0.0336 −0.027–0.037 −0.0255–0.0355 −0.0042–0.0642 −0.0225–0.0425 −0.0165–0.0405 −0.0272–0.0352 −0.0155–0.0495 −0.0115–0.0495 −0.0295–0.0315 −0.01–0.05
2.1 3.5 4.7 3.1 0.9 0.1 0.3 0.3 1.7 0.6 0.8 0.3 1 1.2 0.1 1.3
.0386 .0004 b.0001 .0020 .3921 .9521 .7597 .7483 .0857 .5468 .4092 .8013 .3054 .2221 .9488 .1913
n: all participants; n1: participants with symptom; n2: participants with missing data.
China investigating the clinical features of MDD in China have been geographically restricted and included only patients from either psychiatric hospitals or general hospitals. Subjects in our research were recruited from both general hospitals and psychiatric hospitals, and demonstrated a discrepancy in somatic symptoms of MDD patients who visit different types of institutions. Previous research shows that the prevalence of MDD varies across age. Among people of t 18 to 39 years, 40 to 54 years, and N55 years are 1.15%, 2.72%, and 3.82%, respectively [36]. We divided our subjects into three age groups: b39, 40–54, and ≥ 55 and found that compared to patients in the other two age groups, MDD patients aged between 40 and 54 had the highest occurrence of pre-verbal physical complaints (51.5%), respiratory system complaints (33.0%), trunk pain (29.4%), hyposexuality (34.5%), limb pain (27.9%) and other pain conditions (28.6%). Meanwhile, patients who are beyond 55 years of age exhibited the lowest prevalence of respiratory system complaints (25.2%), hyposexuality (24.0%), and other pain conditions (23.1%), while they also have the highest rate of having low appetite (41.6%) and insomnia (71.5%). Previous domestic research suggests that elderly patients with MDD show increased prevalence of body complaints [37–39]. Other international studies suggest that patients with MDD express somatic complaints more frequently as age increases [8,40–43]. On the other hand other studies have reported that MDD patients beyond 60 years of age have no worse somatic symptoms than other MDD patients [44] or that few somatic symptoms are found in MDD patients over 70 years of age [45]. One investigation of MDD and anxiety disorders associated with somatic symptoms among Chinese patients found that patients who were between 35 and 44 years of age old had the highest severity level of somatic symptoms [46]. Overall then, the results of our study are inconsistent with some studies, and in agreement with others. The differences may be due to different age stratification and participant numbers in age groups. Our research indicates that Chinese young adults who suffer MDD have as similar or even higher levels of somatic symptoms as elderly patients. To understand whether this result is unique to China or the Chinese culture more generally, further research is required. Epidemiologic data from China shows that the lifetime prevalence of MDD among females is twice that of males [26]. The adjusted prevalence for males is 1.55% and for female it is 2.60% [36]. International studies also report that the prevalence of somatic symptoms among female patients with MDD is higher than for male patients [47], specifically in appetite reduction and insomnia [48]. Our research suggests that for patients with MDD, gender mainly makes a difference in somatic symptoms such as pre-verbal physical complaints, low appetite, insomnia, and urinary system complaints. Except for urinary system
complaints, the other three symptoms have higher prevalence rate in female group. Research interview data from the USA National Comorbidity Survey, with a representative nationwide sample, revealed that women were much more likely than men to report clinical depression associated with appetite and sleep disturbances and fatigue, labeled “somatic depression” [47,49]. Depression associated with such somatic symptoms is more prevalent in females than males, and this may underlie the different prevalence rates for MDD for males and females [50]. It has therefore been suggested that if somatic symptoms were factored out, the prevalence of MDD would be the same for each gender [51]. Our investigation suggests somatic depression among females may involve different pathogenesis, so there should be some changes in treatment plans. Our study has some limitations. First, the sample sizes in different age groups varied considerably. Second, as we only analyzed physician reported data, self-reported patient data needs in-depth analysis. Our research group will continue to investigate if there exists differences between self-evaluation of patients and evaluation gathered by physicians. Somatic symptoms, being independent of psychiatric characteristics, physical diseases, and life styles, can be a predictive factor that affects prognosis. Somatic symptoms also have negative consequences for the course of MDD [52]. Patients with MDD who have somatic symptoms may conceal the core symptoms of depression which results in low recognition rate and delayed treatment. Somatic symptoms that MDD patients report should be carefully considered and treated, but not to the neglect of the depressive symptoms. In the future, patients with somatic symptoms should be followed up to discover the reason why prevalence varies in different age ranges and across gender. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi. org/10.1016/j.comppsych.2018.08.013.
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