A principal components analysis of negative affect-related constructs relevant to pain: evidence for a three component structure.

UNLABELLED: A number of negative affect-related constructs are important in pain. Some are general, such as anxiety, depression and negative affectivity, whereas others are more specifically pain-related (eg, fear of pain, pain anxiety, and pain catastrophizing). In addition, some more specific fear-related constructs, such as anxiety sensitivity, illness/injury sensitivity, and fear of negative evaluation have emerged as important to pain. Although these various constructs are considered conceptually separate, there is likely to be overlap between them. Since the extent of this overlap is unknown, the aim of the current study was to investigate these constructs in 1 sample in order to identify their common and unique features. Frequently used psychological measures were completed by 508 pain-free participants. Principal components analysis resulted in the extraction of three components: 1) General distress; 2) Fear of pain from injury/insult; and 3) Cognitive intrusion of pain. The results presented here suggest that there is indeed commonality between constructs, which may be due to either an overlap between items within measures or to close conceptual relatedness. The implications of these core dimensions are discussed with reference to future research and theory. PERSPECTIVE: This article explores the relationships between various negative-affect pain-related measures and discusses the results from a principal components analysis. The findings show that some questionnaires may measure the same latent construct. A measure could be developed to measure these 3 core components more concisely for both clinical and research purposes.

Can a sexually dimorphic index of prenatal hormonal exposure be used to examine cold pressor pain perception in men and women?

There is considerable evidence to suggest that important differences exist between men and women in their experience of pain. Research has now turned to determine what the mechanisms of such differences actually are. One potential explanation is the effect of sex hormones, especially those typically found in greater concentration within women, e.g., estrogen, progesterone. However, it is also possible that other hormones, such as testosterone may be important. The current study employed a non-invasive sexually dimorphic index (digit ratio) that is believed to reflect prenatal exposure to testosterone, and related this to the cold pressor pain experiences of 23 men and 27 healthy women. As expected, females had greater symmetry between the second and fourth digits, and also reported lower pain tolerance levels. Although some significant relationships were found between digit ratio/digit length and cold pressor pain reports they were relatively inconsistent. Furthermore, the main finding, that pain thresholds were positively related to digit ratio in women but not men, is somewhat inconsistent with predictions. The results are discussed in light of methods for investigating the effect of prenatal hormonal exposure on pain sensitivity in men and women.

Assessing the relationship between cold pressor pain responses and dimensions of the anxiety sensitivity profile in healthy men and women.

Anxiety sensitivity (AS) has been shown previously to be an important factor in the perception and experience of experimentally induced pain within healthy adults. The aim of the current study was to extend this research by: (i) using the Anxiety Sensitivity Profile (ASP) as an alternative measure of AS; (ii) examining whether different coping instructions affect pain reports; and (iii) investigating potential differences between men and women. Participants were 50 healthy adults (23 males, 27 females) who were required to complete 2 versions of the cold pressor pain task; one version required the use of control instructions, whereas the other made use of acceptance-based instructions. Although the coping instructions were found to affect pain thresholds (acceptance resulted in lower thresholds), a similar pattern of correlations were found between the pain indexes and AS under both conditions. Of the ASP subscales, the gastrointestinal and cognitive concerns components were found to be the most strongly related to pain experiences. When the analysis was conducted separately for each sex, the ASP scales were related to the self-report measures of pain in women, whereas they were related to the behavioural measures of pain in men. These results not only confirm that AS is associated with experimental pain, but that there may be sex differences in this relationship.