Identifying the blue patient: preoperative screening for depression.

Preoperative depression is an underappreciated comorbidity that has important implications for postoperative outcomes. Screening for symptoms of depression before surgery can identify patients with or without a previous diagnosis of depression who could benefit from perioperative interventions to improve mood. Preoperative screening programmes are feasible to implement, although care must be taken to ensure that patients who are most likely to benefit are included.