Posttraumatic stress disorders in the Nanai after pollution of the Amur River: ethnocultural analysis

Chemical pollution of the Amur River has seriously damaged traditions and caused posttraumatic stress disorder (PTSD) among the Nanai, the indigenous people living along this river. This study was performed to clarify the ethnographic characteristics of PTSD in this unique population. The study group consisted of 75 male and 112 female randomly selected volunteers. PTSD severity measured using scores of the Impact of Event Scale – Revised (Total-I) and Clinical-Administered PTSD Scale (Total-C) was estimated according to demographic and ethnocultural backgrounds, clinical status, and ethnopsychological attitudes toward the Amur River. The differences in averages of Total-I and Total-C were not always the same in the groups divided by ethnographic information. Logistic regression analysis with a dependent variable, possibly without PTSD (Total-I <34 and Total-C <40)/possibly with PTSD (either Total-I ≥34 or Total-C ≥40), and categorical independent variables using ethnographic information extracted a low score when ‘priority values’ and ‘the Amur River for me is’ was “profession” and a high score when ‘dominant role in spousal relationship’ was “self,” when ‘predominant forms of response in stressful situations’ was “try to organize,” when ‘preferred method of medical treatment’ was specific for the Nanai, when “rely on something mystical” was manifested, and when the Amur River was believed to be “sacred”. Those with a pragmatic attitude were less likely to have PTSD. However, those who were required to make decisions within close relationships and were intimate with the Nanai tradition and the Amur River had increased likelihood of PTSD.


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More than two thirds of the general population may experience a significant traumatic event 49 at some point in their lives, and therefore traumatic experiences are relatively common [1]. 50 Mass traumatic events usually involve many people and may result in a wide range of mental 51 and physical health consequences [2]. Personal care is required because such experiences are 52 unusual and unique for each individual [3,4]. 53 Nanai is a small population of indigenous people in the Russian Far East, living along the  In addition, this population has always regarded the Amur River as part of their ethos, 63 symbolic culture, and inner world. They have a shamanistic religion with great reverence for 64 the bear and fire. They also believe that their ancestors originated from the Amur River, 65 which is also the guide to the world of spirits after death. These characteristic beliefs have led 66 to catastrophic effects in this case. The disaster started suddenly. However, pollutants settle to 67 the river bed and freeze into ice, and so their toxicities had prolonged stressful effects, leading 68 to chronic trauma, disadaptation, and powerlessness regarding the situation. PTSD is the most commonly studied and probably the most frequent and debilitating 74 psychological disorder that occurs after traumatic events, disasters, and life-threatening events 75 [1,3,4]. PTSD is the only psychiatric disorder that has an etiological component, i.e., 76 exposure to a traumatic event. According to the Diagnostic and Statistical Manual of Mental 77 Disorders, Fourth Edition (DSM-IV) [7], the diagnosis of PTSD requires three clusters of 78 symptoms, i.e., intrusion/reexperiencing of the event, avoidance/numbness, and hyperarousal 79 from exposure to traumatic events. On the other hand, there is increasing evidence suggesting 80 that PTSD is related not only to mental health impairment [8,9] and social functioning [9][10][11] 81 but also to increased risk of somatic diseases [12][13][14] and overall mortality [15]. 82 In the present study, to detect the special characteristics of PTSD of the indigenous Nanai 83 people after the disaster, the Impact of Event Scale-Revised (IES-R) and the Clinical-  The participants in this study were selected randomly and included 187 indigenous adult 90 Nanai volunteers over 18 years old (the age at which an individual does not require a guardian 91 according to the laws of the Russian Federation) from the general civilian population in the 8 92 villages of Nanai Regional District of Khabarovsk Regional Territory located in the Far East 93 of Russian Federation.

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The field-type survey was performed by visiting the yards in residential areas of the 95 participants during the daytime (usually from 9 am to 6 pm). The survey was carried out interviewer. This study was conducted with all participants' written informed consent to all 6 had experienced an event that involved threatened death or serious injury to which they 126 responded with intense fear, helplessness, or horror.

IES-R (Russian-language certified version)
128 IES-R consists of 22 items based on self-reports measured on a 5-point Likert-type scale 129 ranging from 0 to 4 (not at all, rarely, sometimes, often, and always, respectively) and involved Hyperarousal to physiological symptoms of irritability to describe the following 137 areas; anger and irritability, exaggerated startle response, difficulty in concentration, 138 psychophysiological arousal due to memories, and insomnia. Participants were presented with 139 three groups of questions, Intrusion (7 items), Avoidance (8 items), and Hyperarousal (7 140 items) that can be answered by the scheme of points 0, 1, 3, and 5 for the answer -no,‖ 141 -rarely,‖ -sometimes,‖ and -often,‖ respectively. Three subscale scores were obtained by 142 summing the relevant item scores and the total score was also obtained: score range, Intrusion 143 0 -28, Avoidance 0 -32, Hyperarousal 0 -28, and Total 0 -88. Several cut-off values were 144 reported to detect symptoms indicating a risk and/or vulnerability of PTSD. The mean IES-R 145 score for PTSD was 20, and a score of ≥ 20 on the IES-R was used to estimate the prevalence 146 of PTSD symptoms, with higher IES-R scores indicating more symptoms [8,9]. The PTSD 147 high-risk group was also defined as those scoring 25 or higher, based on the screening results 148 [20,21]. Individuals with a total IES-R score over 33 have been proposed to be regarded as a

CAPS (Russian-language certified version)
151 7 CAPS is a structured interview developed to diagnose and rate the severity of PTSD [18,19]. presented with all questions that could be answered by the scheme scores for frequency and 160 intensity on a 5-point Likert-type scale. For answers of frequency: 0, none, 1, rarely (0% -161 25% of the period), 2; sometimes (25% -50%), 3; often (50% -75%); and 4, always (> 162 75%). For answers of intensity: 0, no such feelings; 1, weak intensity of symptoms; 2, 163 moderate intensity; 3, high intensity; and 4, very high intensity. Estimation of severity scores 164 for each group and the total was made by summing the frequency and intensity ratings. The

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The means of total scores of IER-S and CAPS (respectively, Total-I and Total-C) for all 178 subjects were 31.5 ± 20.1 and 35.0 ± 16.2, respectively (Table 1). Although scores of Total-I 179 and Total-C were significantly correlated, they were not identical. Around 42% (79 of 187) 180 and 36% (67) had Total-I score ≥ 34 and Total-C score ≥ 40 (Fig. 1).

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To evaluate the relationships among symptoms available by these two tests, we utilized 182 principal factor analysis and three factors were extracted (Table 2) (Tables 1 and 3 -5).

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Although all the scores of age group -18 -29‖ tended to be lower than those of other age 193 groups, the difference in Total-C between -18 -29‖ and -30 -39‖ alone was significant 194 ( Table 1). The averages of all IER-S and CAPS scores of -settlement residents‖ were very 195 low and significantly different from those of -villagers.‖ Excluding these two differences, 196 dividing the groups by general demographic information did not show specific tendencies.

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Next, we performed a comparison between groups divided according to ethnocultural 198 information (Table 3). -Inferior‖ feeling regarding their own nationality resulted in a 199 significantly higher Total-C than -equal‖ feeling. -Not tolerate‖ toward other nationalities 200 was usually associated with higher scores for all items compared to -friendly‖ and -tolerate,‖ 201 while only very high Total-C (48.7 ± 16.8) showed a significant difference. The data from 202 questions related to religion seemed not to be useful. For example, 120 participants answered 203 9 that they were -nonbelievers‖ but the number of those who expressed -religious beliefs‖ was 204 153. This contradiction was probably because it was prohibited to have religious beliefs 205 during the Soviet Union period. We omitted these categories from further analysis. The 206 groups divided according to information about family relations, such as dominant role in 207 spouse position, age hierarchy, domestic atmosphere, and having children or not, showed no 208 obvious effects. There were also no obvious effects among the groups divided according to 209 attitude toward ethnic customs, such as observance of national ceremonies and belief of 210 national myths and omens, or attitudes toward mental illness and suicide. Among the groups 211 divided by medical treatment preference, Total-C of -Western‖ was significantly lower than 212 that of -shamanism,‖ with low Avoidance-C and Hyperarousal-C.

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With regard to clinical examination, the effects of psychopathological family history were 214 ambiguous but psychopathological episodes in childhood displayed obvious effects (Table 4).

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Although episodes of organic-type disorders, such as enuresis, night terror, sleep walking, 216 etc., alone and those with affective type disorders, such as phobias, depressive reaction, 217 irritability, etc., alone had no obvious effects, their combination was associated with an 218 extremely high Total-C of 54.6 ± 11.6 due to very high Avoidance-C and Hyperarousal-C.

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Those who had a -balanced‖ response to stressful situations tended to have lower means of all 220 IER-S and CAPS scores than those who reported different responses. However, significant 221 differences in Total-C were observed only against -expressive‖ and -self-aggressive.‖

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Regardless of whether it was significant or not, those who had -no‖ sphere of 223 psychotraumatic situation tended to have low scores. Especially, their Avoidance-C, 224 Hyperarousal-C, and Total-C were significantly lower than those with such spheres. Although 225 significances was observed only in CAPS scores, all of the scores of -always‖ for anxiety 226 were higher than those of -no‖ or -situational.‖ Those who manifested work disadaptation, 227 such as -underperformance‖ and -loss of rhythm,‖ had higher CAPS scores than those who 228 reported -none.‖ Especially, the mean Total-C of those who displayed -underperformance‖ Total-C were significantly lower than those in the -basic and important food‖ group (Table   237 5). However, the effects of whether they really -eat‖ fish from the river or not were not 238 always obvious. Those who thought that this pollution was -not terrible‖ had significantly 239 lower IES-R and CAPS scores than those who accepted it as a -disaster.‖ The groups divided having Total-I < 34 and Total-C < 40 (n = 77, approx. 40%) ( Table 6). As the presence of 245 anxiety and manifestation of work disadaptation seemed to have very high co-linearity with 246 PTSD judgment, they were removed from the determinants. Age groups -30 -39‖ and -40 -247 49‖ showed greater risk than other age groups. -Villagers‖ were at higher risk than 248 -settlement residents,‖ and -state house‖ than -own house‖ or -no house‖ groups. Higher 249 educational level seemed to be protective because the odds ratio of -secondary‖ over 250 -elementary‖ was 0.06 (P = 0.02) ( Table 6) and -higher‖ over -elementary‖ 0.05 (P = 0.07) 251 (data not shown). Relations to other people was significant: -not married‖ was a risk 252 compared to -married‖ as well as -widowed/divorced‖ who were currently single. -Superior‖ 253 feeling regarding their own nationality compared to -inferior‖; -friendly‖ feeling toward other 254 nationalities compared to other feelings; -parity‖ compared to alone; -spouse‖ compared to 255 11 -self‖; -respect but not subordinate‖ compared to -subordinate‖; age hierarchy; and -formal‖ 256 or -conflict‖ compared to -friendly‖ family relation were protective. Similarly, having -no‖ 257 children was protective compared to -yes.‖ In terms of priority values, however, -health‖ was 258 a greater potential risk than -family‖ as well as -profession‖ and -material well-being.‖ 259 -Public recognition‖ was a greater potential risk than the others. With regard to tradition, both 260 -observance of ceremonies‖ and -no observance of ceremonies‖ were risks compared to 261 -sometimes,‖ while medical treatment preference for -shamanism‖ was a risk compared to 262 -traditional‖ and -Western‖ medicine. Individual attitude to mental illness to be both 263 -civilized‖ and -superstitious‖ were risks compared to -uncertain,‖ and the existence of  The groups divided by general demographic conditions did not always show differences in 295 either IES-R or CAPS scores, and so the effects of -settlement resident‖ were difficult to 296 estimate.

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When the groups were divided by ethnocultural and clinicopsychological situations as well as 298 relations to the Amur River, significant differences were more easily found in CAPS than in 299 IES-R. For example, the groups divided by relation to their own nationality and relations to 300 other nationalities showed significant differences only in CAPS scores. Moreover, significant 301 differences in Total-C tended to correspond to those in Avoidance-C and Hyperarousal-C but 302 not those in Intrusion-C. The definition of each category was different between IES-R and 303 CAPS, which was in good accordance with the results of factor analysis. In addition, for 304 comparison of averaged scores of divided groups, CAPS may be utilized more easily than 305 IES-R probably because the standard deviation of CAPS was narrower than that of IES-R.

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High CAPS scores were associated with negative feelings toward both their own and other 307 nationalities, the existence of psychopathological episodes in childhood, and extroversive 308 reaction to stressful situations. It is natural that the existence of anxiety was associated with 309 high CAPS scores as well as manifestation of work and social disadaptation. Especially, 310 manifestation of work disadaptation caused not only high CAPS scores but also high IES-R 311 scores.

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It is obvious that those who felt that this pollution was not terrible had a low risk of PTSD, 313 but the effects of intimacy toward the Amur River were not obvious. Thus, logistic regression 314 analysis was applied to extract risk and protective factors by removing confounding factors.

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The middle-aged group was at higher risk than the younger and older groups, and it is 316 conceivable that those who had high responsibility to the society displayed higher risk. -State 317 house‖ itself was a risk and was one of the reasons why -villagers‖ were at elevated risk 318 because all state houses were in the village. Higher education seemed to be protective, and in 319 fact people engaged in -education‖ were at lower risk than those with other professions. This 320 pollution was caused by another nation, and so it was natural that maintaining a -friendly‖ 321 attitude toward other nationalities was protective.

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Experience of -marriage,‖ and -equal‖ or -partner's dominance‖ in spouse position were 323 protective but having -friendly‖ family and -having children‖ were risk factors. These 324 findings are not surprising because having a good relationship with a partner seems to be 325 supportive, but once they had family to be protected, this situation may represent a burden.

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When priority values were estimated, -family‖ was protective compared to -health‖ and 327 -public recognition,‖ and a risk factor compared to -profession.‖ It is not surprising that 328 -health‖ was a potential risk factor. However, with regard to sphere of psychotraumatic 329 situation, both -family‖ and -profession‖ were recognized as risk factors. These findings may 330 have been because -family‖ and -profession‖ were recognized sometimes to be the same and 331 sometimes not the same. To have -public recognition‖ as a priority value was recognized as 332 14 the highest risk factor, which may be due to the same background where the -middle-aged 333 group‖ and some professions showed increased risk.
No factor was extracted form gender, native language, superstition, attitude to suicide, and fish in the Amur was polluted.