["Clinical Psychology &Psychotherapy, Volume 33, Issue 4, July/August 2026. ", "\nABSTRACT\nImpairments in interpersonal functioning are a core transdiagnostic feature of personality disorders (PDs). While interpersonal problems are known to worsen clinical outcomes, their mediating role between PDs and mental health requires further empirical examination. The study aims were: (1) to analyse gender differences in PDs, mental health and interpersonal problems; (2) to study the correlations between study variables; and (3) to examine the mediating role of interpersonal problems in the relationship between PDs and global mental health. The final sample comprised 291 participants (Mage = 38.30, SD = 13.80; 66.3% women) from a clinical population who completed the International Personality Disorder Examination (IPDE), the Inventory of Interpersonal Problems (IIP‐32) and the Symptom Checklist (SCL‐90). Women scored higher on the self‐sacrificing dimension (p = 0.023), and a significant gender difference was also found for narcissistic personality disorder, with men scoring slightly higher than women (p = 0.048). Higher scores on PDs and greater interpersonal difficulties were strongly associated with mental health problems (ρ‐values between 0.467 and 0.571). Finally, interpersonal problems mediated the association between personality cluster scores and mental health problems. Interpersonal problems, PDs and mental health symptoms form an interlinked pattern of psychological distress. Consequently, therapeutic interventions for PDs must prioritize the modification of maladaptive relational styles with the aim of preventing or mitigating co‐occurring mental health problems.\n"]