Psychometric investigation into the construct of neurasthenia and its related conditions: A comparative study on Chinese in Hong Kong and Mainland China

Objectives. The present study employed a psychometric approach to investigate the construct of neurasthenia in respect of two fundamental issues: (1) the major characteristics that constitute neurasthenia as a distinctive construct; and (2) the cultural variability in the construct of neurasthenia between Chinese samples in different cultural settings. Another major aim of the present research was to refine and update the Chinese Neurasthenia Scale originally developed by the author for assessing the construct of neurasthenia.;Methods. Two independent samples of Chinese from Hong Kong (N = 868) and Changsha (N = 1001) were compared on the newly refined Chinese Neurasthenia Scale (CN5-12), as well as a number of mood, personality and cognitive measures, including Depression Anxiety Stress Scale-21 (DASS-21), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Eysenck Personality Inventory (EPI) and Automatic Thought Questionnaire (ATQ). The construct of neurasthenia and its relationship with the relevant measures was examined by way of detailed psychometric, correlational and factor analyses. Different structural models of neurasthenia in relation to stress, anxiety, and depression were tested and compared in the two Chinese samples using Structural Equation Modeling. Comparisons of sample means were assessed by ANCOVA with potential confounds being controlled as covariates.;Results. All of the scales administered including the newly refined Chinese Neurasthenia scale (cNs-12) were found to attain very good psychometric properties. According to factor analyses, the construct of neurasthenia as assessed by CNs-12 was found to comprise four major components, namely (a) Irritability and Nervousness, (b) musculoskeletal Aches and Pains, (c) Functional Impairment, and (d) Sleep disturbances and Fatigue. contrary to current taxonomic systems, irritability rather than fatigue or weakness was found to represent the major feature of neurasthenia. As shown by correlational and multiple regression analyses, the construct of neurasthenia also showed closer resemblance to the concept of stress when compared to anxiety and depression. According to the results of SEM, both irritability and chronic fatigue were found to be the specific markers for neurasthenia when distinguishing from anxiety and depression. Moreover, the presence of irritability might constitute a specific marker to differentiate neurasthenia from chronic fatigue syndrome (CFS). No significant sample differences were found in the factor structure of neurasthenia, as well as its pattern of relationships with the relevant mood, personality and cognitive variables between the two Chinese samples. The most striking sample difference pertained to a general tendency for the Changsha sample to endorse a lower level of distress on both somatic and psychological symptoms than the Hong Kong sample.;Conclusion. The construct of neurasthenia was assessed to be characterized mainly by features of irritability and nervousness, which resembles more to the concept of stress rather than anxiety or depression. As predicted by recent theories on the relationship between negative affects, neurasthenia was found to share both unique and common characteristics with stress, anxiety and depression. In addition to sharing a common general distress factor, specific postulations were made about the distinctiveness of neurasthenia as a clinical syndrome from anxiety, depression and CFS. Between-group analysis showed a relatively stable and coherent construct of neurasthenia between the Hong Kong and Changsha samples. The early view that neurasthenia represents a disguise form of depression by way of somatization was not supported by the present results. The general tendency to endorse lower scores on both the somatic and psychological items for all of the administered scales in Changsha reflects a possible change in cultural templates of "neurasthenia" and "somatization" to more psychologically oriented templates of "stress" and "social desirability" for expressing somatic and psychological distress in modern china. The present research demonstrated the use and advantages of adopting a psychometric approach to investigate the construct of neurasthenia in a cross-cultural setting.