1. Background

Postwar survivors of combat continue to suffer from ill health. It has been seen among military service members from World War II, the Vietnam War, the Middle East conflict, and the Persian Gulf War. According to studies conducted among veterans of World War II, the Persian Gulf War, and the Korean War chronic mental health problems are prevalent among them. World War II veterans still experience war-related psychological distress even after fifty years. The study among older Korean War veterans reports over five times more depressed than the non-veteran group. Depressive symptoms among postwar veterans increase over time.

After the Vietnam War, the vast majority of American combat veterans were depressed. Classical depressive symptoms such as psychomotor retardation, difficulties in initiating and maintaining sleep, feeling of worthlessness, and concentration and memory difficulties were often present. Many veterans had generalized sense of helplessness about their experiences in Vietnam and prospects for the future.

The situation of the Vietnamese veterans was different. Vietnamese had justified reasons for engagement in the war. However, the casualties those Vietnamese veterans experienced were more than those of any other nation's veterans who involved in the Vietnam War suffered. After the Vietnam War, about 300,000 American veterans were wounded while the number was about 1,700,000 for Vietnamese veterans. Many studies on depressive symptoms have been conducted among American veterans of Vietnam War but not among Vietnamese veterans.

Victims of traumatic events cope with psychological difficulties they experience in many ways. Social support has been indicated as one of the important strategies to cope with such situation. In the situation of war stressors, previous studies found that combat veterans with low levels of social support are more likely to experience elevated levels of distress, or that social support sustains the person through the emotional turbulence following a trauma. Social support has been shown as an important protecting factor for depressive symptoms among elderly people in general population. Among the group of the elderly veterans, social support had the important role in post-war adjustment. Social support was a predictor of depressive symptoms at later life among veterans of the World War II and the Korean War. Support from family had the role of helping them adapt to civilian life and sometimes to come to terms with the long-term effects of wounds. Support from friends, especially friends through the war service, was a valuable resource for discussing war experiences among World War II veterans.

Previous study reported that marital status emerges as an important predictor of mental health. This can be explained that late-life support by the spouse is of importance to their psychological health. Widowhood has been found to be strongly associated with depression in some instances. In addition, people who remain single lack filial and spousal support. Under such circumstances, life events may thus be rendered much more unbearable, especially at an advanced age.

2. Objectives

The objectives of the study are as follows. The first one was to describe the sources of social support among the elderly veterans in Thaibinh, Vietnam. The second one was to identify the association between three sources of social support and depressive symptoms among the Vietnamese veterans. For this, we hypothesized that veterans who had more social support experience less depressive symptoms, and this association may vary between the sources of social support. The third objective was to identify the association between social support and depressive symptoms in relation to marital status. We hypothesized that the non-married veterans had lower levels of total social support (particularly family support) and higher levels of depressive symptoms than the married veterans. We also hypothesized that the association of non-family social support such as friend support would be greater among the non-married veterans than among married veterans. The information might be useful in identifying a high risk group for poor mental health and establishing a way of intervention for the high-risk group in Vietnamese veterans.

3. Methods

From June to August 2010, we conducted this cross-sectional study in Thaibinh, Vietnam. We included male military veterans aged 65 years and older who participated in the Vietnam War. We used a random sampling method to select 6 communes from totally 287 communes. This study was conducted through face-to-face interviews with a structured questionnaire among 828 participants in six communes in Thaibinh, Vietnam. This study was approved by the Ethical Committee of the University of Tokyo, Japan, and the Ethical Committee of Thaibinh Medical University, Vietnam.

Depressive symptoms were measured by the Center for Epidemiological Studies Depression Scale (CES-D). Social support was measured by the Multidimensional Scale of Perceived Social Support (MSPSS). War-related factors were characterized by wound in wartime history and history of loss of relative(s)/friend(s) during wartime. Physical disability was measured by two scales: the Activity of Daily Living (ADL) scale and the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) scale. Simultaneous linear regression was used to identify the association between social support and depressive symptoms, stratified by marital status. The factors included in the model were: socio-demographic factors, war-related factors, physical disability, and social support. We performed all statistical analyses using the Stata version 11. We conducted univariate and bivariate analysis to describe the sources of social support and to examine the association between depressive symptoms and social support. Multivariate analysis were employed to determine the association between social support and depressive symptoms, accounting for all confounding factors.

4. Results

The married veterans reported significantly higher scores on all three sources of support including support from family (p<0.001), support from friends (p<0.001), and support from significant other (p<0.001) compared to non-married veterans. Total social support was also significantly higher in the married group as compared to the non-married group (p<0.001). Total scores on the depressive symptoms among married veterans was lower than among non-married veterans. Average CES-D was significantly higher in the non-married group (22.54 ± 11.37) than in the married group (14.02 ±8.2 ; p < 0.001)

The association between depressive symptoms and total social support were described according to participant's marital status. In both of married and non-married veterans, social support were significantly negatively associated with depressive symptoms (p<0.001).

On the other hand, three sources of social support were uniquely associated with depressive symptoms among married and non-married veterans. The association between social support and depressive symptoms was stronger in non-married veterans than in married veterans. Family support shows strong association among married, but not among non-married. Also, friend support was significantly associated with depressive symptoms among non-married, but not among married veterans. Significant other support was not associated with depressive symptoms both in married and non-married veterans.

5. Conclusions

In conclusion, this study elucidated the sources of social support including family support, friend support and significant other support, and association between social support and depressive symptoms among elderly military veterans aged 65 years and older in Thaibinh, Vietnam.

The married veterans reported higher scores on all three sources of support compared to the non-married veterans. However, total social support was negatively associated with depressive symptoms among both group of married and non-married veterans. Family plays an important role in supporting elderly veterans in Vietnam in the relation with depressive symptoms, which is particularly true for the married-veterans.

This study suggest that the non-married veterans are at higher risk of depression, which makes social support become more meaningful for them in terms of predicting depressive symptoms compared to the married one. Among different types of social support to the non-married veterans, friend support had significant association with depressive symptoms. This result implies that the role of friends in alleviating mental health problems seems to be important among non-married veterans.

Veterans in Vietnam had different characteristics as compared to veterans from other countries involved in the Vietnam War; veterans with functional disabilities also appeared to report higher levels of depressive symptoms. Nevertheless, social support remained an important factor associated with their depressive symptoms. Therefore depressive symptoms should be of concern of not only health staff members but also family and friends around the elderly veterans.

The ease of obtaining a high response rate is itself an indication of interest in the effects of war experience in the veteran population. Evidence presented here demonstrate that there is a need for a comprehensive understanding of social support and depressive symptoms among veterans in their later life. Veterans are now in their 70s and 80s and still looking forward to many years of active and fulfilling life as long as their needs are recognized and acted upon.

本研究は2010年6月から8月にかけてベトナム、タイピン省に在住するベトナム戦争に従事した65歳以上の退役軍人を対象にソーシャルサポートと欝に関する質問調査を実施し、その関連性を分析したものであり、下記の結果を得ている。

1.ベトナムの退役軍人における欝とソーシャルサポートの現状を把握するために、国際的に使用されているCenter for Epidemiological Studies Depression Scale(CES-D)およびMultidimensional Scale of Perceived Social Support(MSPSS)のベトナムバージョンを使用し、65歳以上の退役軍人828名に対し、インフォームドコンセントを得た後、質問調査を行った。CES-Dは20問から成る自己報告式の質問票であり、欝を計測するための国際的な指標である。しかしながらベトナムでは20問の内1問は質問の妥当性を欠くということで使用されていない。従って本研究でも19問の質問票を使用した。MSPSSは12問から成る家族、友人、大切な人からのソーシャルサポートの有無を図るスケールであり、それぞれ回答は'非常に反対する'から'非常に賛成する'まで5段階のリッカート尺度で計測される。

2.その結果として、CES-Dの平均値は15.4(SD9.2)であった。ソーシャルサポートの結果は平均値によって'高い'または'低い'レベルに分けられた。同様に家族からのサポート、友人からのサポート、大切な人からのサポートも平均値によって'高い''低い'に分けられた。これらの関連は重線形回帰分析によって解析された。CES-Dの結果は質問票の性質上、国際的比較は不可能であったが、いずれもベトナムの退役軍人との間で鯵とソーシャルサポートは統計的に有意な相関があった。

3.また、家族、友人、大切な人からのサポートに分けそれぞれ欝との関連を重線形回帰分析によって解析した結果、家族からのソーシャルサポートとの間に強い相関性がみられた。これにより、ベトナムの退役軍人における家族の役割の重要性が示唆された。

4.更に、参加者を妻帯者、非妻帯者(未婚、離婚、死別)に区別した場合、妻帯者は693人であり、非妻帯者は135人であった。それぞれのCES-Dの平均値は妻帯者14.02(8.02)、非妻帯者2254(11.37)であり、両グループ間の平均値の差は有意であった。そこでそれぞれのグループにて家族からのサポート、友人からのサポート、大切な人からのサポートとの関連をカイ二乗検定にて調べたところ、いずれも妻帯者のほうがより多くのサポートを感受していることがわかった。しかし、それぞれの層別に重線形回帰分析を行った結果、両グループにおいてソーシャルサポートは欝と強い関連性を持っことがわかった。

5.しかし、層別重線形回帰分析にて更に家族からのサポート、友人からのサポート、大切な人からのサポートと欝との関連を分析したところ、それぞれの種類のソーシャルサポートと欝との関連に特徴がみられた。妻帯者のグループでは家族からのサポートをより感受する人が、非妻帯者のグループでは友人からのサポートを感受する人がより低いCES-Dスコアと有意に相関していた。この結果により、非妻帯者は妻帯者と比べてソーシャルサポートを感受しにくい傾向があるにも関わらず、中でも友人からのサポートは、退役軍人にとって欝を減少させるために重要な存在であることがわかった。

上記の結果を以って、本研究はベトナムの退役軍人の欝の傾向とソーシャルサポートの現状を明らかにし、また、妻帯者と非妻帯者間のサポートの感受の差異や、欝と強い関連のあるサポートのタイプを解明した。ベトナム戦争に従事したベトナム退役軍人を対象にしたこのような研究は初めてである。また、ソーシャルサポートを受けにくい立場にいる非妻帯者へのメンタルヘルスの向上に重要なエビデンスを提供した。本研究は調査地に特異的な提言をし、重要な貢献をなしたと考えられることから、学位の授与に値するものと考えられる。