Introduction
The concept of psychological resilience is derived from a previously published psychiatric report investigating children who appeared to be relatively unaffected by adverse life events. Psychosocial researchers have noted that some individuals are able to cope and survive better than others in the face of adverse conditions, and resilience research has focused on factors or characteristics that help individuals manage adversity.
1,2 Other studies have focused on the importance of resilience as a protective factor against the development of posttraumatic stress disorder (PTSD).
3,4
Resilience, a dynamic process in which individuals display positive adaptive skills despite experiencing significant adversity or trauma,
5 is a measure of the ability to cope with stress.
6 Resilient individuals have a comprehensive ability to adapt to various work and social situations as well as psychological and physical health states.
The original definition of resilience was framed in terms of a personality trait. More recently, resilience has been redefined as a dynamic, modifiable process. This definition has led to the development of resilience-based interventions and facilitated studies on the outcomes of such interventions.
5 The recent literature has focused on the derivation of resilience-based intervention and prevention programs, as well as genetic and other biological effects of resilience.
6-8 Psychological resilience is suggested to predict one's physiological response to stress. Thus, resilient individuals are able to use positive emotion to "bounce back" from stressful encounters. For example, researchers found that after the September 11, 2001 terrorist attack in New York, USA, resilient people had a more positive emotional response to the event, and these positive emotional responses were associated with a reduced incidence of depression.
9,10 Resilience has also been shown to protect against posttraumatic debility in the face of adversity and enhance pharmacotherapy outcomes in depression and anxiety.
11 Moreover, resilience may play a key role as a protective factor against depression and other psychiatric disorders.
12 Resilience is strongly associated with positive affect, which in turn is positively related to self-esteem.
13
In Korea, research on resilience has been relatively uncommon to date, although active interest is growing in positive psychology and resilience among Korean psychiatrists.
14,15 Several clinical instruments have been developed to assess resilience.
16-19 The Resilience Scale (RS), developed by Wagnild and Young
16 in 1993, is a reliable and valid tool to measure resilience and has been used with a wide range of study populations.
20 In 2003, Connor and Davidson
21 developed a new scale to assess resilience, known as the Connor-Davidson Resilience Scale (CD-RISC). They found the full-scale reliability and validity of the CD-RISC to be psychometrically strong with community populations, primary care and general psychiatric outpatients, and with individuals receiving treatment for generalized anxiety disorder and PTSD.
21 The CD-RISC is widely used in Western countries for resilience studies such as those addressing coping with stress and responses to pharmacotherapy for psychiatric and physical illness.
11,22 In Asia, however, only one study examining a Chinese population has been published.
23 In this study, we aimed to develop and validate a Korean version of the Connor-Davidson Resilience Scale (K-CD-RISC), to evaluate its potential for cross-cultural application in Korean subjects.
Discussion
In the present study, we found that the K-CD-RISC exhibited good reliability and validity. Internal consistency (Cronbach's α) of the K-CD-RISC was 0.93; this coefficient was within the optimal range for this value and consistent with the Cronbach's α of 0.89 reported for the original CD-RISC. The test-retest reliability of the K-CD-RISC was determined to be 0.70 (p<0.01) via Pearson's correlation.
K-CD-RISC scores were positively correlated with self-esteem and negatively correlated with depression, posttraumatic stress, and perceived stress, similar to what was observed with the initial characterization of the CD-RISC (PSS, r=-0.32, p<0.01). Psychological resilience can predict the physiological response to stress, and resilient individuals are able to use positive emotion to "bounce back" from stressful encounters. Resilience protects against posttraumatic debility in the face of adversity and enhances pharmacotherapeutic outcomes for depression and anxiety.
11 Resilience is a protective factor against depression, anxiety, PTSD, and other psychiatric disorders,
12 and is strongly associated with positive affect, which in turn is positively related to self-esteem.
13 The correlation patterns we observed confirm our hypotheses and provide convincing evidence regarding the validity of the K-CD-RISC among the Korean subjects.
In our study, five components with eigenvalues greater than 1.00 were extracted, which explained 57.2% of the variance in baseline K-CD-RISC scores, consistent with the original studies on the CD-RISC structure. The first factor, which accounted for 38.0% of the variation, was identified as hardiness, and was represented by nine items on the questionnaire. Factors 2, 3, 4, and 5 explained 6.2%, 4.7%, 4.2%, and 4.1% of the variation, respectively. As noted, the first factor was hardiness (including items 18, 19, 15, 16, 17, 23, 14, 4, and 1). The second factor was persistence (items 11, 21, 24, 25, 22, 5, 10, and 12). The third factor was optimism (items 9, 8, 7, and 6), the fourth factor was support (items 13 and 2), and the fifth factor was being spiritual in nature (items 20 and 3). The reliability of factors 1-5 according to Cronbach's α was 0.87, 0.87, 0.58, 0.59, and 0.25, respectively (
Table 5).
Factor 1 representing hardiness implied that the subject was "not easily frustrated when facing an adverse situation and had strong internal belief or boldness". The first factor included all items from factor 1 (hardiness) from the original CD-RISC in addition to items 15 and 23. In the original article, items 15 and 23 were "I can make decisions that are unpopular or difficult to others" and "I like challenges," respectively. Some aspects of the first factor in our study were implicated in factor 4 (persistence) of the original CD-RISC. Decision-making requires conviction and propulsive force, but "difficulty" was more closely related to endurance. As Korean participants focused more on "decision-making" than on "difficulty," items 15 and 23 reflected aspects of hardiness. Factor 2 was identified as "persistence." Factor 2 included a large portion of items from factor 4 (persistence) of the original study as well as items 21 and 22. This factor focused on tolerance to negative affect, the strengthening effects of stress and circumspect thinking, and decision-making when coping with stress. Factor 3 represented optimism. Optimism is the feeling of being hopeful about the future or about the chances of success of a particular event. Items involved in factor 3 included "see the humorous side of things", "coping with stress strengthens", "tend to bounce back after illness or hardship", and "things happen for a reason, whether good or bad". Item 9, 8, 7, and 6 were all related to optimism. Factor 4 represented support and implied the ability to receive help from another. Items involved in factor 4 were "know where to turn for help" and "close and secure relationships" Social support and meaningful relationships contribute to resilient outcomes.
Factor 5 represented spiritual influence, but two items (items 20 and 3) did not load on any factor, and the Cronbach's α of factor 5 was relatively low (0.25). In the original study, item 3 ("sometimes fate or God can help") was related to spiritual influence. Spirituality correlates with closeness to God and feelings of interconnectedness in the world and between living things.
33,34 This concept is based on Christian values. However, item 3 may have had a different meaning to Korean subjects because the word 'God' was partially lost in translation. Many Korean subjects interpreted item 3 as a question about luck, chance, or things out of their control, and thus is may not have reflected spiritual influence. Therefore, future use of this scale to should include amendments to items 20 and 3. Our results differed from assessments of the original CD-RISC. The original study by Connor and Davidson resulted in a five-factor solution, whereas in the Chinese version a three-factor structure (tenacity, strength, optimism) explained 45% of the variance.
23 Campbell-Stills and Stein
24 reported that a four-factor structure did not include spiritual influence, consistent with what we report here. Resilience protects individuals against adversity, and the concept of resilience is thought to be universal. However, cultural differences arise due to distinct historical, social, and geological environments, and the concept of resilience may differ across cultures. This may explain why the K-CD-RISC had a different factor structure than the original United States version of the scale.
21
The mean CD-RISC scores in the general population, primary care patients, psychiatric outpatients, patients with generalized anxiety disorder, and patients with PTSD in the US were 80.4 (SD=12.8), 71.8 (SD=18.4), 68.0 (SD=15.3), 62.4 (SD=10.7), 47.8 (SD=19.5), and 52.8 (SD=20.4), respectively.
21 In our study, the mean score on the K-CD-RISC was 61.2 (SD=13.0). This discrepancy might be attributable to subjects suffering from mild or moderate anxiety and depressive symptoms who were not excluded, and to different socioepidemiological variables such as age, sex, religion, and education. Some variation is likely to occur due to cultural differences.
The present findings must be cautiously interpreted considering the following limitations. First, while convergent validity was demonstrated, divergent validity was not evaluated. Second, the study subjects were not recruited randomly from the general population and included only university students, hospital nurses, and firefighters. The study sample consisted of healthy, young (mean=27.4 years of age, SD=5.16) subjects, mostly female (91%) and unmarried. Thus, generalizing the results across the general population would be difficult.
In conclusion, the K-CD-RISC had good psychometric properties and can be used as a reliable and valid tool to assess resilience, although some cultural variation was apparent. Further studies are needed to fully evaluate the K-CD-RISC, including its application to the general population, primary care patients, psychiatric outpatients, patients with PTSD, and those with other special psychiatric disorders.