Association between pet ownership and mental health in university students with borderline personality disorder symptoms

Approximately 9.7% of university students exhibit symptoms of borderline personality disorder (BPD), characterized by disturbed self-identity, low self-esteem, and emotion dysregulation. Caring for a pet may enhance self-esteem and provide a sense of purpose, potentially benefiting those with BPD. This study aimed to explore the relationship between pet ownership and mental health in 346 university students with BPD symptoms. Participants were classified as pet owners or non-pet owners. Mental health outcomes were assessed using validated self-report instruments, including the Outcome Inventory-21 (OI-21), the Rosenberg Self-Esteem Scale–Thai Revised (RSES-TR), the Revised Thai version of the Multidimensional Scale of Perceived Social Support (R-Thai MSPSS), the Thai version of the 10-item Perceived Stress Scale (T-PSS-10), and the Inner Strength-Based Inventory (iSBI). No significant differences were observed between the two groups in adverse mental health outcomes. However, pet owners demonstrated higher levels of inner strengths, including truthfulness (t (240) = 4.10, p < 0.001), wisdom (t (240) = 3.72, p < 0.001), generosity (t (242) = 2.16, p = 0.032), tolerance (t (242) = 2.44, p = 0.016), determination (t (237) = 2.43, p = 0.017), and loving-kindness (t (242) = 2.04, p = 0.043). Notably, dog owners reported lower levels of anxiety (t (237) = -2.40, p = 0.017), depression (t (243) = -2.03, p = 0.043), and somatization (t (244) = -2.56, p = 0.025), while also scoring higher in self-esteem (t (242) = 2.15, p = 0.032) compared to non-pet owners. In contrast, no significant differences in mental health outcomes were found between cat owners and non-pet owners. These findings suggest that pet ownership, especially ownership of dogs, may be positively associated with mental health among university students with BPD symptoms. Future research should explore intervention-based approaches to validate these results.