Biopsychosocial Aspects of Pain Sensitivity

Abstract

Every fifth person worldwide suffers from chronic pain, with immense costs for both individuals and societies. Hence, chronic pain has been claimed as a global health priority. To understand pain, research from biological, behavioural, and social sciences is necessary, with the discipline of psychology at the forefront. Interestingly, basal pain sensitivity has been found to predict chronification in postoperative pain and has been argued to be a risk factor in the transition process from acute to persistent pain. Therefore, the present dissertation aimed to advance the basic understanding of biopsychosocial aspects of pain sensitivity. <br /> In the scope of the overarching research project, five studies have been designed, conducted, analysed, and published. Study 1 included a literature review and several meta-analyses investigating the catechol-O-methyltransferase (COMT) gene, which had previously been discussed as an important pain sensitivity gene. Study 2 examined brain activity patterns during self-referential pain imaginations by means of functional magnetic resonance imaging (fMRI) and asked whether pain sensitivity and locus of control were predictors of brain activation contrasts. Study 3 reported the development and validation of a new psychological instrument to be used in pain research, the General Attitudes Towards Pain Inventory (GATPI). Study 4 made use of this questionnaire and investigated the conjunct influence of pain attitudes and reward/punishment sensitivity on subjective and laboratory measures of pain sensitivity. Study 5 finally presented data from a novel vignette design, allowing for the differential analysis of sex and gender on pain sensitivity attributions to others. <br /> Findings suggest a role of a haplotype in the COMT gene in pain sensitivity while also implying an influence of internal locus of control and negative pain attitudes. Moreover, two clusters of participants were identified, showing distinct patterns of pain attitudes and reward/punishment sensitivity. Across six different measures, pain avoiders were found to be significantly more pain sensitive compared to pain approachers. The fMRI study further demonstrated activity in pain-related brain areas during self-referential pain imagination, although neither pain sensitivity nor locus of control were significant predictors. Last but not least, observer sex, target sex and gender, as well as ambivalent sexism towards women and gender ontological beliefs, were found to influence pain sensitivity judgments of others. <br /> The current dissertation offers a small but nonetheless valuable contribution to basic pain sensitivity research by means of a wide range of biopsychological methods. If comprehensive longitudinal studies in the future can corroborate pain sensitivity as a risk factor for chronic pain and resolve existing causality dilemmas, the here-found results could serve to guide preventive measures. These may include school programmes, training for health care providers, and personalised pain care for at-risk patients, pursuing the common goal to reduce suffering.