A cluster analysis of psychological variables to identify profiles of Nociplastic pain: A cross-sectional study in women with fibromyalgia, chronic headache and vulvodynia

Background: Nociplastic pain (NP) arises from altered nociceptive processing without detectable tissue damage and is common in conditions such as fibromyalgia (FM), vulvodynia (VU), and chronic headaches (CH). Objectives: This study aimed to identify subgroups of NP patients using cluster analysis based on psychological variables, including central sensitivity syndrome manifestations, environmental sensitivity, traumatic experiences, personality traits, defense mechanisms, and alexithymia. A secondary aim was to compare these clusters with clinical diagnoses (FM, CH, VU, and comorbid cases) to explore potential overlaps between psychological profiles and conditions. Methods: A total of 895 Italian women were recruited via snowball sampling through patient associations. Participants completed a web survey featuring self-administered psychological measures assessing central sensitivity, environmental sensitivity, traumatic experiences, personality traits, defense mechanisms, and alexithymia. Results: Cluster analysis identified three meaningful groups—“severe,” “moderate,” and “mild” psychological impairment—based on 20 psychological variables. A one-way MANOVA revealed significant differences among clusters, with central sensitization, alexithymia, and personality traits contributing most to the variance. Chi-square analysis showed significant differences in the distribution of NP conditions across clusters. FM and comorbid cases were associated with “moderate” and “severe” impairment clusters, indicating more compromised psychological profiles compared to other conditions. Conclusions: These findings highlight the presence of distinct psychological profiles within NP conditions, supporting the need for a multidimensional approach to assessment and treatment. Tailored psychological interventions addressing these profiles could improve outcomes for NP patients.