Abstract: Pain perception, including nociceptive component, sensory-discriminative component (intensity), motivational-affective component (unpleasantness) and cognitive-behavioral component, may be influenced by psychological factors such as pain-related fear, psychological distress, and somatization. Though effect on pain perception of pain-related fear has been widely confirmed and thus based its effect on chronic pain initiation, development and maintenance, no studies have yet assured its dominance against other psychological factors such as psychological distress and somatization. One methodological concern with research in the area has been a reliance on using single scales to measure complex constructs such as psychological distress and pain-related fear. Furthermore, a majority of studies have used chronic pain samples, so it is not clear whether possible elevations in somatization, psychological distress and pain-related fear influenced pain perception or resulted from experiences of ongoing pain. This cross-sectional research was designed to clarify these issues within a general university student sample. A pilot study was designed to evaluate the structure and distinctiveness of somatization, psychological distress and pain-related fear using multiple rather than single measures to represent each factor. Then, the impact of each of these psychological dimensions on pain perception was evaluated within a laboratory pain paradigm. 653 university students (69.60% female) completed a battery of five pain-related fear scales, three measures of psychological distress not specifically related to pain, and two somatization scales. Exploratory factor analysis (EFA) and confirmatory factor analyses (CFA) were respectively conducted on random equal subsets of the total sample to determine whether initially derived factor solutions were replicable in a new group. 8 weeks later, 105 participants (70.45% female) completed the questionnaire battery and Cold Pressor Test (CPT), controlling for order effects. Hierarchical regression models and moderation/mediation analyses were conducted to assess effects of these three psychological factors on four indices of pain perception (i.e., threshold, tolerance, intensity, unpleasantness). EFA results identified a three factor solution consistent with the psychological constructs above. CFA confirmed that this solution had a good fit for the data. The main results were as follows: (1) the pain-related fear and psychological distress factors significantly and positively predicted both pain intensity and pain unpleasantness, but impact of psychological distress were fully mediated by pain-related fear, (2) higher scores on the pain-related fear predicted lower pain tolerance levels to a marginally-significant extent (p=0.097) while neither somatization nor psychological distress had effects, and (3) among participants reporting high levels of pain-related fear, elevations in somatization had significant negative associations with pain unpleasantness. Mediation of pain-related fear on psychological distress may indicate non-pain-oriented factors influence subjective pain experience primarily through their relations with pain-specific factors. The negative association between somatization and subjective pain experience may indicate the tendency to focus on somatic symptoms is a protective adaptation that helps to maintain homeostasis, specifically among vulnerable individuals including those who are highly pain-fearful and undergoing noxious stimulation. Taken together, results indicated that pain-related fear, rather than psychological distress or somatization, was the key dimension associated with exaggerated pain perception, especially regarding subjective intensity and unpleasantness of pain. To cope with accidental pain better in daily life, efforts of reducing exaggerated pain-related fear were recommended.

Key words: pain, pain-related fear, psychological distress, somatization, cold pressor test, mediation, moderation

摘要： 首次在无痛群体中比较疼痛恐惧、心理忧虑和躯体化对疼痛感知的预测作用大小及调节和中介关系。以多个同类量表得分的Z分数加和作为三者的因子分，以冷压痛觉测验（CPT）疼痛指标（阈限、耐受性、强度、不愉快度）为目标变量，通过分层回归及调节和中介作用分析，发现疼痛恐惧对疼痛不愉快度的预测作用最强，心理忧虑对疼痛体验（强度、不愉快度）的预测作用被疼痛恐惧完全中介，躯体化只有在高疼痛恐惧条件下才显著负向预测疼痛不愉快度。综上，疼痛恐惧是三因素中预测CPT疼痛体验的主要因素。

关键词: 疼痛, 疼痛恐惧, 心理忧虑, 躯体化, 冷压痛觉测验, 中介效应, 调节效应