Differentiation of self – the ability to emotionally self-regulate and to maintain a sense of autonomy within a deep intimate relationship – has been proposed as a relevant factor in couple satisfaction, but the mechanisms underlying this association remain unclear. Sexual desire and intimacy have recently drawn increased attention due to the proposal that some of the relational benefits of long-term intimacy (e.g., predictability) might be detrimental to desire and satisfaction. This study aimed to test a model illustrating the role played by differentiation of self in couple satisfaction through the underlying mechanisms of sexual desire and intimacy, in a survey of 428 heterosexual individuals. The findings supported the proposed model, suggesting that differentiation of self is a predictor of desire, intimacy and couple satisfaction. Desire mediated the association between differentiation and couple satisfaction, and also the association between differentiation and intimacy. Intimacy mediated the association between desire and satisfaction. The model was sustained for women, but a different mechanism was found for men. The results provide support for the close association between intimacy, sexual desire and satisfaction, while suggesting that differentiation of self has a fundamental role in sexual desire, intimacy and couple satisfaction.

The scientific community underlines that one of the main challenges for couples is the effect of time on sexual desire. Some studies suggest that although some dimensions associated with intimacy tend to increase during the relationship, sexual desire and the related constructs tend to decrease. Some researchers have recently suggested that couples’ relationships with high degrees of sharing and fusion might be particularly detrimental for the sustenance of sexual desire. However, the authors found no empirical or theoretical studies that investigate the relations between intimacy and desire. Recovering the concept of differentiation as a possible influencing variable between intimacy and desire, this article develops reflections on this theme, which is of paramount relevance for the couple viability.

The fibromyalgia syndrome (FM) is a chronic widespread pain condition whose etiology remains unknown and no treatment has satisfactory levels of success. A meta-analysis has identified a distinct Minnesota Multiphasic Personality Inventory-2 (MMPI-2) clinical profile between FM female patients and healthy controls, and differences between FM and other chronic pain condition with clear etiology have also been found. However, heterogeneity in this population has been suggested in several studies. We aim to assess clinical aspects in FM patients, based on personality psychopathology characteristics, in order to explore heterogeneity and the existence of core common aspects. In this cross-sectional study, a relatively homogeneous sample of 56 female FM patients (M_age = 45.95, SD_age = 9.39) was assessed through MMPI-2. A K-Means cluster analysis identified two clusters, one (n = 24) with clinically significant levels in Negative Emotionality and Introversion scales. Subsequent MANOVAs identified important features of this cluster on several MMPI-2 dimensions. Moreover, several dimensions are clinically elevated in both clusters. In conclusion, the combination of psychopathological negative emotionality, interpersonal isolation, and low hedonic capacity, in a group of patients, has implications for the daily living and treatment of FM patients, and several core aspects of FM need to be addressed.