Associations between depression, pain behaviors, and partner responses to pain in metastatic breast cancer.

Women with metastatic breast cancer (MBC) rely on their partners for emotional and practical support. They also experience significant pain and depression, which can trigger maladaptive pain behaviors (eg, distorted ambulation). The biopsychosocial model of pain posits that partner solicitous responses can reinforce pain behaviors, whereas punishing or distracting responses can minimize their occurrence. This study explored how psychosocial variables (ie, depression and partner responses) influence patient pain behaviors and partner responses in 191 couples coping with MBC. Because few studies have examined the biopsychosocial model in cancer, it also examined associations between partner responses and patient pain behaviors. Multilevel models showed that depression partially mediated: (1) associations between patients' and partners' reports of patient pain (MPI) and their ratings of patient pain behaviors (PBCL), accounting for 41% to 71% of the variance; and (2) associations between both partners' reports of patient pain and the partner's distracting and punishing responses (MPI), accounting for 66% to 75% of the variance. Partner punishing responses moderated associations between patient pain severity and pain behaviors. Specifically, punishing responses were associated with more pain behaviors for patients with low levels of pain and fewer pain behaviors for patients with higher levels of pain (effect size r=.18). These findings provide partial support for the biopsychosocial model of pain but also clarify and extend it in the cancer context. Future pain management programs in MBC may benefit from addressing both partners' depression levels and teaching partners to engage in fewer punishing responses when the patient is experiencing low levels of pain.